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10g Release 1 (10.1)

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156
UTL_HTTP

The UTL_HTTP package makes Hypertext Transfer Protocol (HTTP) callouts from SQL and PL/SQL. You can use it to access data on the Internet over HTTP.

When the package fetches data from a Web site using HTTPS, it requires Oracle Wallet Manager to set up an Oracle wallet. Non-HTTPS fetches do not require an Oracle wallet.

See Also:

This chapter contains the following topics:


Using UTL_HTTP


Overview

With UTL_HTTP, you can write PL/SQL programs that communicate with Web (HTTP) servers. UTL_HTTP also contains a function that can be used in SQL queries. The package also supports HTTP over the Secured Socket Layer protocol (SSL), also known as HTTPS, directly or through an HTTP proxy. Other Internet-related data-access protocols (such as the File Transfer Protocol (FTP) or the Gopher protocol) are also supported using an HTTP proxy server that supports those protocols.


Constants

Table 156-1 Constants
Constant and Syntax Purpose

HTTP_VERSION_1_0 CONSTANT VARCHAR2(10) := 'HTTP/1.0';

Denotes HTTP version 1.0 that can be used in the function begin_request.

HTTP_VERSION_1 CONSTANT VARCHAR2(10) := 'HTTP/1.1';

Denotes HTTP version 1.1 that can be used in the function begin_request.

DEFAULT_HTTP_PORT CONSTANT PLS_INTEGER := 80;

The default TCP/IP port (80) at which a Web server or proxy server listens

DEFAULT_HTTPS_PORT CONSTANT PLS_INTEGER := 443;

The default TCP/IP port (443) at which an HTTPS Web server listens

Table 156-2  HTTP 1.1 Status Codes:
Constant and Syntax

HTTP_VERSION_1_0 CONSTANT VARCHAR2(10) := 'HTTP/1.0';

HTTP_VERSION_1 CONSTANT VARCHAR2(10) := 'HTTP/1.1';

DEFAULT_HTTP_PORT CONSTANT PLS_INTEGER := 80;

DEFAULT_HTTPS_PORT CONSTANT PLS_INTEGER := 443;

The following denote all the HTTP 1.1 status codes:

HTTP_CONTINUE CONSTANT PLS_INTEGER := 100;

HTTP_SWITCHING_PROTOCOLS CONSTANT PLS_INTEGER := 101;

HTTP_OK CONSTANT PLS_INTEGER := 200;

HTTP_CREATED CONSTANT PLS_INTEGER := 201;

HTTP_ACCEPTED CONSTANT PLS_INTEGER := 202;

HTTP_NON_AUTHORITATIVE_INFO CONSTANT PLS_INTEGER := 203;

HTTP_NO_CONTENT CONSTANT PLS_INTEGER := 204;

HTTP_RESET_CONTENT CONSTANT PLS_INTEGER := 205;

HTTP_PARTIAL_CONTENT CONSTANT PLS_INTEGER := 206;

HTTP_MULTIPLE_CHOICES CONSTANT PLS_INTEGER := 300;

HTTP_MOVED_PERMANENTLY CONSTANT PLS_INTEGER := 301;

HTTP_FOUND CONSTANT PLS_INTEGER := 302;

HTTP_SEE_OTHER CONSTANT PLS_INTEGER := 303;

HTTP_NOT_MODIFIED CONSTANT PLS_INTEGER := 304;

HTTP_USE_PROXY CONSTANT PLS_INTEGER := 305;

HTTP_TEMPORARY_REDIRECT CONSTANT PLS_INTEGER := 307;

HTTP_BAD_REQUEST CONSTANT PLS_INTEGER := 400;

HTTP_UNAUTHORIZED CONSTANT PLS_INTEGER := 401;

HTTP_PAYMENT_REQUIRED CONSTANT PLS_INTEGER := 402;

HTTP_FORBIDDEN CONSTANT PLS_INTEGER := 403;

HTTP_NOT_FOUND CONSTANT PLS_INTEGER := 404;

HTTP_NOT_ACCEPTABLE CONSTANT PLS_INTEGER := 406;

HTTP_PROXY_AUTH_REQUIRED CONSTANT PLS_INTEGER := 407;

HTTP_REQUEST_TIME_OUT CONSTANT PLS_INTEGER := 408;

HTTP_CONFLICT CONSTANT PLS_INTEGER := 409;

HTTP_GONE CONSTANT PLS_INTEGER := 410;

HTTP_LENGTH_REQUIRED CONSTANT PLS_INTEGER := 411;

HTTP_PRECONDITION_FAILED CONSTANT PLS_INTEGER := 412;

HTTP_REQUEST_ENTITY_TOO_LARGE CONSTANT PLS_INTEGER := 413;

HTTP_REQUEST_URI_TOO_LARGE CONSTANT PLS_INTEGER := 414;

HTTP_UNSUPPORTED_MEDIA_TYPE CONSTANT PLS_INTEGER := 415;

HTTP_REQ_RANGE_NOT_SATISFIABLE CONSTANT PLS_INTEGER := 416;

HTTP_EXPECTATION_FAILED CONSTANT PLS_INTEGER := 417;

HTTP_NOT_IMPLEMENTED CONSTANT PLS_INTEGER := 501;

HTTP_BAD_GATEWAY CONSTANT PLS_INTEGER := 502;

HTTP_SERVICE_UNAVAILABLE CONSTANT PLS_INTEGER := 503;

HTTP_GATEWAY_TIME_OUT CONSTANT PLS_INTEGER := 504;

HTTP_VERSION_NOT_SUPPORTED CONSTANT PLS_INTEGER := 505;


Types

REQ Type

Use this PL/SQL record type to represent an HTTP request.

Syntax
TYPE req IS RECORD (
   url           VARCHAR2(32767),
   method        VARCHAR2(64),
   http_version  VARCHAR2(64));
Parameters
Table 156-3 REQ Type Parameters
Parameter Description

url

The URL of the HTTP request. It is set after the request is created by begin_request.

method

The method to be performed on the resource identified by the URL. It is set after the request is created by begin_request.

http_version

The HTTP protocol version used to send the request. It is set after the request is created by begin_request.

Usage Notes

The information returned in REQ from the interface begin_request is for read only. Changing the field values in the record has no effect on the request.

There are other fields in REQ record type whose names begin with the prefix private_. The fields are private and are intended for use by implementation of the UTL_HTTP package. You should not modify the fields.

RESP Type

This PL/SQL record type is used to represent an HTTP response.

Syntax
TYPE resp IS RECORD (
   status_code    PLS_INTEGER,
   reason_phrase  VARCHAR2(256),
   http_version   VARCHAR2(64));
Parameters
Table 156-4 RESP Type Parameters
Parameter Description

status_code

The status code returned by the Web server. It is a 3-digit integer that indicates the results of the HTTP request as handled by the Web server. It is set after the response is processed by get_response.

reason_phrase

The short textual message returned by the Web server that describe the status code. It gives a brief description of the results of the HTTP request as handled by the Web server. It is set after the response is processed by get_response.

http_version

The HTTP protocol version used in the HTTP response. It is set after the response is processed by get_response.

Usage Notes

The information returned in RESP from the interface get_response is read-only. There are other fields in the RESP record type whose names begin with the prefix private_. The fields are private and are intended for use by implementation of the UTL_HTTP package. You should not modify the fields.

COOKIE and COOKIE_TABLE Types

The COOKIE type is the PL/SQL record type that represents an HTTP cookie. The COOKIE_TABLE type is a PL/SQL index-by-table type that represents a collection of HTTP cookies.

Syntax
TYPE cookie IS RECORD (
   name  VARCHAR2(256),
   value  VARCHAR2(1024),
   domain  VARCHAR2(256),
   expire  TIMESTAMP WITH TIME ZONE,
   path  VARCHAR2(1024),
   secure  BOOLEAN,
   version  PLS_INTEGER,
   comment  VARCHAR2(1024));

TYPE cookie_table IS TABLE OF cookie INDEX BY binary_integer;
Fields of COOKIE Record Type

Table 156-5 shows the fields for the COOKIE and COOKIE_TABLE record types.

Table 156-5 Fields of COOKIE and COOKIE_TABLE Type
Field Description

name

The name of the HTTP cookie

value

The value of the cookie

domain

The domain for which the cookie is valid

expire

The time by which the cookie will expire

path

The subset of URLs to which the cookie applies

secure

Should the cookie be returned to the Web server using secured means only.

version

The version of the HTTP cookie specification the cookie conforms. This field is NULL for Netscape cookies.

comment

The comment that describes the intended use of the cookie. This field is NULL for Netscape cookies.

Usage Notes

PL/SQL programs do not usually examine or change the cookie information stored in the UTL_HTTP package. The cookies are maintained by the package transparently. They are maintained inside the UTL_HTTP package, and they last for the duration of the database session only. PL/SQL applications that require cookies to be maintained beyond the lifetime of a database session can read the cookies using get_cookies, store them persistently in a database table, and re-store the cookies back in the package using add_cookies in the next database session. All the fields in the cookie record, except for the comment field, must be stored. Do not alter the cookie information, which can result in an application error in the Web server or compromise the security of the PL/SQL and the Web server applications. See "Retrieving and Restoring Cookies".

CONNECTION Type

Use the PL/SQL record type to represent the remote hosts and TCP/IP ports of a network connection that is kept persistent after an HTTP request is completed, according to the HTTP 1.1 protocol specification. The persistent network connection may be reused by a subsequent HTTP request to the same host and port. The subsequent HTTP request may be completed faster because the network connection latency is avoided. connection_table is a PL/SQL table of connection.

For a direct HTTP persistent connection to a Web server, the host and port fields contain the host name and TCP/IP port number of the Web server. The proxy_host and proxy_port fields are not set. For an HTTP persistent connection that was previously used to connect to a Web server using a proxy, the proxy_host and proxy_port fields contain the host name and TCP/IP port number of the proxy server. The host and port fields are not set, which indicates that the persistent connection, while connected to a proxy server, is not bound to any particular target Web server. An HTTP persistent connection to a proxy server can be used to access any target Web server that is using a proxy.

The ssl field indicates if Secured Socket Layer (SSL) is being used in an HTTP persistent connection. An HTTPS request is an HTTP request made over SSL. For an HTTPS (SSL) persistent connection connected using a proxy, the host and port fields contain the host name and TCP/IP port number of the target HTTPS Web server and the fields will always be set. An HTTPS persistent connection to an HTTPS Web server using a proxy server can only be reused to make another request to the same target Web server.

Syntax
TYPE connection IS RECORD (
   host  VARCHAR2(256),
   port  PLS_INTEGER,
   proxy_host  VARCHAR2(256),
   proxy_port  PLS_INTEGER,
   ssl  BOOLEAN);

TYPE connection_table IS TABLE OF connection INDEX BY BINARY_INTEGER;

Operational Notes

Operational Flow

The UTL_HTTP package provides access to the HTTP protocol. The interfaces must be called in the order shown in Figure 156-1, or an exception will be raised.

Figure 156-1 Flow of the Core UTL_HTTP Package

Text description of arpls006.gif follows

Text description of the illustration arpls006.gif

The following can be called at any time:

Simple HTTP Fetches

REQUEST and REQUEST_PIECES take a string uniform resource locator (URL), contact that site, and return the data (typically HTML) obtained from that site.

You should not expect REQUEST or REQUEST_PIECES to succeed in contacting a URL unless you can contact that URL by using a browser on the same machine (and with the same privileges, environment variables, and so on.)

If REQUEST or REQUEST_PIECES fails (for example, if it raises an exception, or if it returns an HTML-formatted error message, but you believe that the URL argument is correct), then try contacting that same URL with a browser to verify network availability from your machine. You may have a proxy server set in your browser that needs to be set with each REQUEST or REQUEST_PIECES call using the optional proxy parameter.


Note:

UTL_HTTP can also use environment variables to specify its proxy behavior. For example, on UNIX, setting the environment variable http_proxy to a URL uses that service as the proxy server for HTTP requests. Setting the environment variable no_proxy to a domain name does not use the HTTP proxy server for URLs in that domain. When the UTL_HTTP package is executed in the Oracle database server, the environment variables are the ones that are set when the database instance is started.


See Also:

Simple HTTP Fetches in a Single Call Subprograms

Session Settings

Session settings manipulate the configuration and default behavior of UTL_HTTP when HTTP requests are executed within a database user session. When a request is created, it inherits the default settings of the HTTP cookie support, follow-redirect, body character set, persistent-connection support, and transfer timeout of the current session. Those settings can be changed later by calling the request interface. When a response is created for a request, it inherits those settings from the request. Only the body character set can be changed later by calling the response interface.

See Also:

Session Settings Subprograms

HTTP Requests

The HTTP Requests group of subprograms begin an HTTP request, manipulate attributes, and send the request information to the Web server. When a request is created, it inherits the default settings of the HTTP cookie support, follow-redirect, body character set, persistent-connection support, and transfer timeout of the current session. The settings can be changed by calling the request interface.

See Also:

HTTP Requests Subprograms

HTTP Responses

The HTTP Responses group of subprograms manipulate an HTTP response obtained from GET_RESPONSE and receive response information from the Web server. When a response is created for a request, it inherits settings of the HTTP cookie support, follow-redirect, body character set, persistent-connection support, and transfer timeout from the request. Only the body character set can be changed by calling the response interface.

See Also:

HTTP Responses Subprograms

HTTP Cookies

The UTL_HTTP package provides subprograms to manipulate HTTP cookies.

See Also:

HTTP Cookies Subprograms

HTTP Persistent Connections

The UTL_HTTP package provides subprograms to manipulate persistent connections.

See Also:

HTTP Persistent Connections Subprograms

Error Conditions

The UTL_HTTP package provides subprograms to retrieve error information.

See Also:

Error Conditions Subprograms


Exceptions

Table 156-6 lists the exceptions that the UTL_HTTP package interface can raise. By default, UTL_HTTP raises the exception request_failed when a request fails to execute. If the package is set to raise a detailed exception by set_detailed_excp_support, the rest of the exceptions will be raised directly (except for the exception end_of_body, which will be raised by read_text, read_line, and read_raw regardless of the setting).

Table 156-6  UTL_HTTP Exceptions
Exception Error Code Reason Where Raised

request_failed

29273

The request fails to executes

Any HTTP request or response interface when detailed_exception is disabled

bad_argument

29261

The argument passed to the interface is bad

Any HTTP request or response interface when detailed_exception is enabled

bad_url

29262

The requested URL is badly formed

begin_request, when detailed_exception is enabled

protocol_error

29263

An HTTP protocol error occurs when communicating with the Web server

set_header, get_response, read_raw, read_text, and read_line, when detailed_exception is enabled

unknown_scheme

29264

The scheme of the requested URL is unknown

begin_request and get_response, when detailed_exception is enabled

header_not_found

29265

The header is not found

get_header, get_header_by_name, when detailed_exception is enabled

end_of_body

29266

The end of HTTP response body is reached

read_raw, read_text, and read_line, when detailed_exception is enabled

illegal_call

29267

The call to UTL_HTTP is illegal at the current state of the HTTP request

set_header, set_authentication, and set_persistent_conn_support, when detailed_exception is enabled

http_client_error

29268

From get_response, the response status code indicates that a client error has occurred (status code in 4xx range). Or from begin_request, the HTTP proxy returns a status code in the 4xx range when making an HTTPS request through the proxy.

get_response, begin_request when detailed_exception is enabled

http_server_error

29269

From get_response, the response status code indicates that a client error has occurred (status code in 5xx range). Or from begin_request, the HTTP proxy returns a status code in the 5xx range when making an HTTPS request through the proxy.

get_response, begin_request when detailed_exception is enabled

too_many_requests

29270

Too many requests or responses are open

begin_request, when detailed_exception is enabled

partial_multibyte_exception

29275

No complete character is read and a partial multibyte character is found at the end of the response body

read_text and read_line, when detailed_exception is enabled

transfer_timeout

29276

No data is read and a read timeout occurred

read_text and read_line, when detailed_exception is enabled


NOTE:

The partial_multibyte_char and transfer_timeout exceptions are duplicates of the same exceptions defined in UTL_TCP. They are defined in this package so that the use of this package does not require the knowledge of the UTL_TCP. As those exceptions are duplicates, an exception handle that catches the partial_multibyte_char and transfer_timeout exceptions in this package also catch the exceptions in the UTL_TCP.


For REQUEST and REQUEST_PIECES, the request_failed exception is raised when any exception occurs and detailed_exception is disabled.


Examples

The following examples demonstrate how to use UTL_HTTP.

General Usage

SET serveroutput ON SIZE 40000
  
DECLARE
  req   utl_http.req;
  resp  utl_http.resp;
  value VARCHAR2(1024);
BEGIN

  utl_http.set_proxy('proxy.my-company.com', 'corp.my-company.com');

  req := utl_http.begin_request('http://www-hr.corp.my-company.com');
  utl_http.set_header(req, 'User-Agent', 'Mozilla/4.0');
  resp := utl_http.get_response(req);
  LOOP
    utl_http.read_line(resp, value, TRUE);
    dbms_output.put_line(value);
  END LOOP;
  utl_http.end_response(resp);
EXCEPTION
  WHEN utl_http.end_of_body THEN
    utl_http.end_response(resp);
END;

Retrieving HTTP Response Headers

SET serveroutput ON SIZE 40000
  
DECLARE
  req   utl_http.req;
  resp  utl_http.resp;
  name  VARCHAR2(256);
  value VARCHAR2(1024);
BEGIN

  utl_http.set_proxy('proxy.my-company.com', 'corp.my-company.com');
 
  req := utl_http.begin_request('http://www-hr.corp.my-company.com');
  utl_http.set_header(req, 'User-Agent', 'Mozilla/4.0');
  resp := utl_http.get_response(req);

  dbms_output.put_line('HTTP response status code: ' || resp.status_code);
  dbms_output.put_line('HTTP response reason phrase: ' || resp.reason_phrase);

  FOR i IN 1..utl_http.get_header_count(resp) LOOP
    utl_http.get_header(resp, i, name, value);
    dbms_output.put_line(name || ': ' || value);
  END LOOP;
  utl_http.end_response(resp);
END;

Handling HTTP Authentication

SET serveroutput ON SIZE 40000
  
CREATE OR REPLACE PROCEDURE get_page (url      IN VARCHAR2,
                                      username IN VARCHAR2 DEFAULT NULL,
                                      password IN VARCHAR2 DEFAULT NULL,
                                      realm    IN VARCHAR2 DEFAULT NULL) AS
  req       utl_http.req;
  resp      utl_http.resp;
  my_scheme VARCHAR2(256);
  my_realm  VARCHAR2(256);
  my_proxy  BOOLEAN;
BEGIN

  -- Turn off checking of status code. We will check it by ourselves.
  utl_http.http_response_error_check(FALSE);

  req := utl_http.begin_request(url);
  IF (username IS NOT NULL) THEN
    utl_http.set_authentication(req, username, password); -- Use HTTP Basic 
Authen. Scheme
  END IF;

  resp := utl_http.get_response(req);
  IF (resp.status_code = utl_http.HTTP_UNAUTHORIZED) THEN
    utl_http.get_authentication(resp, my_scheme, my_realm, my_proxy);
    IF (my_proxy) THEN
       dbms_output.put_line('Web proxy server is protected.');
       dbms_output.put('Please supplied the required ' || my_scheme || ' 
authentication username/password for realm ' || my_realm || ' for the proxy 
server.');
    ELSE
      dbms_output.put_line('Web page ' || url || ' is protected.');
      dbms_output.put('Please supplied the required ' || my_scheme || ' 
authentication username/password for realm ' || my_realm || ' for the Web 
page.');
    END IF;
    utl_http.end_response(resp);
    RETURN;
  END IF;

  FOR i IN 1..utl_http.get_header_count(resp) LOOP
    utl_http.get_header(resp, i, name, value);
    dbms_output.put_line(name || ': ' || value);
  END LOOP;
  utl_http.end_response(resp);

END;

Retrieving and Restoring Cookies

CREATE TABLE my_cookies (
    session_id  INTEGER,
    name        VARCHAR2(256),
    value       VARCHAR2(1024),
    domain      VARCHAR2(256),
    expire      DATE,
    path        VARCHAR2(1024),
    secure      VARCHAR2(1),
    version     INTEGER
);

CREATE SEQUENCE session_id;

SET serveroutput ON SIZE 40000

REM Retrieve cookies from UTL_HTTP

CREATE OR REPLACE FUNCTION save_cookies RETURN PLS_INTEGER AS
  cookies        utl_http.cookie_table;
  my_session_id  PLS_INTEGER;
  secure         VARCHAR2(1);
BEGIN

  /* assume that some cookies have been set in previous HTTP requests. */

  utl_http.get_cookies(cookies);
  select session_id.nextval into my_session_id from dual;

  FOR i in 1..cookies.count LOOP
    IF (cookies(i).secure) THEN
      secure := 'Y';
    ELSE
      secure := 'N';
    END IF;
    insert into my_cookies
    values (my_session_id, cookies(i).name, cookies(i).value,
cookies(i).domain,
           cookies(i).expire, cookies(i).path, secure, cookies(i).version);
  END LOOP;

  RETURN my_session_id;

END;
/

REM Retrieve cookies from UTL_HTTP

CREATE OR REPLACE PROCEDURE restore_cookies (this_session_id IN PLS_INTEGER)
AS
  cookies        utl_http.cookie_table;
  cookie         utl_http.cookie;
  i              PLS_INTEGER := 0;
  CURSOR c (c_session_id PLS_INTEGER) IS
    SELECT * FROM my_cookies WHERE session_id = c_session_id;
BEGIN

  FOR r IN c(this_session_id) LOOP
    i := i + 1;
    cookie.name   := r.name;
    cookie.value  := r.value;
    cookie.domain := r.domain;
    cookie.expire := r.expire;
    cookie.path   := r.path;
    IF (r.secure = 'Y') THEN
      cookie.secure := TRUE;
    ELSE
      cookie.secure := FALSE;
    END IF;
    cookie.version := r.version;
    cookies(i) := cookie;
  END LOOP;

  utl_http.clear_cookies;
  utl_http.add_cookies(cookies);

END;
/

Subprogram Groups


Simple HTTP Fetches in a Single Call Subprograms

Table 156-7  UTL_HTTP Subprograms--Simple HTTP Fetches in a Single Call
Subprogram Description

REQUEST Function

Returns up to the first 2000 bytes of the data retrieved from the given URL. This function can be used directly in SQL queries

REQUEST_PIECES Function

Returns a PL/SQL table of 2000-byte pieces of the data retrieved from the given URL


Session Settings Subprograms

Table 156-8  UTL_HTTP Subprograms--Session Settings
Subprogram Description

GET_BODY_CHARSET Procedure

Retrieves the default character set of the body of all future HTTP requests

GET_COOKIE_SUPPORT Procedure

Retrieves the current cookie support settings

GET_DETAILED_EXCP_SUPPORT Procedure

Checks if the UTL_HTTP package will raise a detailed exception or not

GET_FOLLOW_REDIRECT Procedure

Retrieves the follow-redirect setting in the current session

GET_PERSISTENT_CONN_SUPPORT Procedure

Checks if the persistent connection support is enabled and gets the maximum number of persistent connections in the current session

GET_PROXY Procedure

Retrieves the current proxy settings

GET_RESPONSE_ERROR_CHECK Procedure

Checks if the response error check is set or not

GET_TRANSFER_TIMEOUT Procedure

Retrieves the current network transfer timeout value

SET_BODY_CHARSET Procedures

Sets the default character set of the body of all future HTTP requests when the media type is text and the character set is not specified in the Content-Type header

SET_COOKIE_SUPPORT Procedures

Sets whether or not future HTTP requests will support HTTP cookies; sets the maximum number of cookies maintained in the current database user session

SET_DETAILED_EXCP_SUPPORT Procedure

Sets the UTL_HTTP package to raise a detailed exception

SET_FOLLOW_REDIRECT Procedures

Sets the maximum number of times UTL_HTTP follows the HTTP redirect instruction in the HTTP responses to future requests in the get_response function

SET_PERSISTENT_CONN_SUPPORT Procedure

Sets whether or not future HTTP requests will support the HTTP 1.1 persistent connection; sets the maximum number of persistent connections maintained in the current database user session

SET_PROXY Procedure

Sets the proxy to be used for requests of HTTP or other protocols

SET_RESPONSE_ERROR_CHECK Procedure

Sets whether or not get_response raises an exception when the Web server returns a status code that indicates an error--a status code in the 4xx or 5xx ranges

SET_TRANSFER_TIMEOUT Procedure

Sets the timeout value for UTL_HTTP to read the HTTP response from the Web server or proxy server

SET_WALLET Procedure

Sets the Oracle Wallet used for all HTTP requests over Secured Socket Layer (SSL), that is, HTTPS


HTTP Requests Subprograms

Table 156-9  UTL_HTTP Subprograms--HTTP Requests
Subprogram Description

BEGIN_REQUEST Function

Begins a new HTTP request. UTL_HTTP establishes the network connection to the target Web server or the proxy server and sends the HTTP request line.

END_REQUEST Procedure

Ends the HTTP request.

SET_HEADER Procedure

Sets an HTTP request header. The request header is sent to the Web server as soon as it is set.

SET_AUTHENTICATION Procedure

Sets HTTP authentication information in the HTTP request header. The Web server needs this information to authorize the request.

SET_BODY_CHARSET Procedures

Sets the character set of the request body when the media type is text but the character set is not specified in the Content-Type header.

SET_COOKIE_SUPPORT Procedures

Enables or disables support for the HTTP cookies in the request.

SET_FOLLOW_REDIRECT Procedures

Sets the maximum number of times UTL_HTTP follows the HTTP redirect instruction in the HTTP response to this request in the GET_RESPONSE Function.

SET_PERSISTENT_CONN_SUPPORT Procedure

Enables or disables support for the HTTP 1.1 persistent-connection in the request.

WRITE_LINE Procedure

Writes a text line in the HTTP request body and ends the line with new-line characters (CRLF as defined in UTL_TCP).

WRITE_RAW Procedure

Writes some binary data in the HTTP request body.

WRITE_TEXT Procedure

Writes some text data in the HTTP request body.


HTTP Responses Subprograms

Table 156-10  UTL_HTTP Subprograms--HTTP Responses
Subprogram Description

END_RESPONSE Procedure

Ends the HTTP response. It completes the HTTP request and response.

GET_AUTHENTICATION Procedure

Retrieves the HTTP authentication information needed for the request to be accepted by the Web server as indicated in the HTTP response header.

GET_HEADER Procedure

Returns the nth HTTP response header name and value returned in the response.

GET_HEADER_BY_NAME Procedure

Returns the HTTP response header value returned in the response given the name of the header.

GET_HEADER_COUNT Function

Returns the number of HTTP response headers returned in the response.

GET_RESPONSE Function

Reads the HTTP response. When the function returns, the status line and the HTTP response headers have been read and processed.

READ_LINE Procedure

Reads the HTTP response body in text form until the end of line is reached and returns the output in the caller-supplied buffer.

READ_RAW Procedure

Reads the HTTP response body in binary form and returns the output in the caller-supplied buffer.

READ_TEXT Procedure

Reads the HTTP response body in text form and returns the output in the caller-supplied buffer.

SET_BODY_CHARSET Procedures

Sets the character set of the response body when the media type is "text" but the character set is not specified in the "Content-Type" header.


HTTP Cookies Subprograms

Table 156-11  UTL_HTTP Subprograms--HTTP Cookies
Subprogram Description

ADD_COOKIES Procedure

Adds the cookies maintained by UTL_HTTP.

CLEAR_COOKIES Procedure

Clears all cookies maintained by the UTL_HTTP package.

GET_COOKIE_COUNT Function

Returns the number of cookies currently maintained by the UTL_HTTP package set by all Web servers.

GET_COOKIES Function

Returns all the cookies currently maintained by the UTL_HTTP package set by all Web servers.


HTTP Persistent Connections Subprograms

Table 156-12  UTL_HTTP Subprograms--HTTP Persistent Connections
Subprogram Description

CLOSE_PERSISTENT_CONN Procedure

Closes an HTTP persistent connection maintained by the UTL_HTTP package in the current database session.

CLOSE_PERSISTENT_CONNS Procedure

Closes a group of HTTP persistent connections maintained by the UTL_HTTP package in the current database session.

GET_PERSISTENT_CONN_COUNT Function

Returns the number of network connections currently kept persistent by the UTL_HTTP package to the Web servers.

GET_PERSISTENT_CONNS Procedure

Returns all the network connections currently kept persistent by the UTL_HTTP package to the Web servers.


Error Conditions Subprograms

Table 156-13  UTL_HTTP Subprograms--Error Conditions
Subprogram Description

GET_DETAILED_SQLCODE Function

Retrieves the detailed SQLCODE of the last exception raised.

GET_DETAILED_SQLERRM Function

Retrieves the detailed SQLERRM of the last exception raised.


Summary of UTL_HTTP Subprograms

Table 156-14  UTL_HTTP Package Subprograms
Subprogram Description

ADD_COOKIES Procedure

Adds the cookies maintained by UTL_HTTP (see HTTP Cookies and HTTP Cookies Subprograms)

BEGIN_REQUEST Function

Begins a new HTTP request. UTL_HTTP establishes the network connection to the target Web server or the proxy server and sends the HTTP request line (see HTTP Requests and HTTP Requests Subprograms)

CLEAR_COOKIES Procedure

Clears all cookies maintained by the UTL_HTTP package (see HTTP Cookies and HTTP Cookies Subprograms)

CLOSE_PERSISTENT_CONN Procedure

Closes an HTTP persistent connection maintained by the UTL_HTTP package in the current database session (see HTTP Persistent Connections and HTTP Persistent Connections Subprograms)

CLOSE_PERSISTENT_CONNS Procedure

Closes a group of HTTP persistent connections maintained by the UTL_HTTP package in the current database session (see HTTP Persistent Connections and HTTP Persistent Connections Subprograms)

END_REQUEST Procedure

Ends the HTTP request (see HTTP Requests and HTTP Requests Subprograms)

END_RESPONSE Procedure

Ends the HTTP response. It completes the HTTP request and response (see HTTP Responses and HTTP Responses Subprograms)

GET_AUTHENTICATION Procedure

Retrieves the HTTP authentication information needed for the request to be accepted by the Web server as indicated in the HTTP response header (see HTTP Responses and HTTP Responses Subprograms)

GET_BODY_CHARSET Procedure

Retrieves the default character set of the body of all future HTTP requests (see Session Settings and Session Settings Subprograms)

GET_COOKIE_COUNT Function

Returns the number of cookies currently maintained by the UTL_HTTP package set by all Web servers (see HTTP Cookies and HTTP Cookies Subprograms)

GET_COOKIE_SUPPORT Procedure

Retrieves the current cookie support settings (see Session Settings and Session Settings Subprograms)

GET_COOKIES Function

Returns all the cookies currently maintained by the UTL_HTTP package set by all Web servers (see HTTP Cookies and HTTP Cookies Subprograms)

GET_DETAILED_EXCP_SUPPORT Procedure

Checks if the UTL_HTTP package will raise a detailed exception or not (see Session Settings and Session Settings Subprograms)

GET_DETAILED_SQLCODE Function

Retrieves the detailed SQLCODE of the last exception raised (see Error Conditions and Error Conditions Subprograms)

GET_DETAILED_SQLERRM Function

Retrieves the detailed SQLERRM of the last exception raised (see Error Conditions and Error Conditions Subprograms)

GET_FOLLOW_REDIRECT Procedure

Retrieves the follow-redirect setting in the current session (see Session Settings and Session Settings Subprograms)

GET_HEADER Procedure

Returns the nth HTTP response header name and value returned in the response (see HTTP Responses and HTTP Responses Subprograms)

GET_HEADER_BY_NAME Procedure

Returns the HTTP response header value returned in the response given the name of the header (see HTTP Responses and HTTP Responses Subprograms)

GET_HEADER_COUNT Function

Returns the number of HTTP response headers returned in the response (see HTTP Responses and HTTP Responses Subprograms)

GET_PERSISTENT_CONN_COUNT Function

Returns the number of network connections currently kept persistent by the UTL_HTTP package to the Web servers (see HTTP Persistent Connections and HTTP Persistent Connections Subprograms)

GET_PERSISTENT_CONN_SUPPORT Procedure

Sees whether or not future HTTP requests will support the HTTP 1.1 persistent connection; sets the maximum number of persistent connections maintained in the current database user session (see Session Settings and Session Settings Subprograms)

GET_PERSISTENT_CONN_SUPPORT Procedure

Checks if the persistent connection support is enabled and gets the maximum number of persistent connections in the current session (see Session Settings and Session Settings Subprograms)

GET_PERSISTENT_CONNS Procedure

Returns all the network connections currently kept persistent by the UTL_HTTP package to the Web servers (see HTTP Persistent Connections and HTTP Persistent Connections Subprograms)

GET_PROXY Procedure

Retrieves the current proxy settings (see Session Settings and Session Settings Subprograms)

GET_RESPONSE Function

Reads the HTTP response. When the function returns, the status line and the HTTP response headers have been read and processed (see HTTP Responses and HTTP Responses Subprograms)

GET_RESPONSE_ERROR_CHECK Procedure

Checks if the response error check is set or no (see Session Settings and Session Settings Subprograms)t

GET_TRANSFER_TIMEOUT Procedure

Retrieves the current network transfer timeout value (see Session Settings and Session Settings Subprograms)

READ_LINE Procedure

Reads the HTTP response body in text form until the end of line is reached and returns the output in the caller-supplied buffer (see HTTP Responses and HTTP Responses Subprograms)

READ_RAW Procedure

Reads the HTTP response body in binary form and returns the output in the caller-supplied buffer (see HTTP Responses and HTTP Responses Subprograms)

READ_TEXT Procedure

Reads the HTTP response body in text form and returns the output in the caller-supplied buffer (see HTTP Responses and HTTP Responses Subprograms)

REQUEST Function

Returns up to the first 2000 bytes of the data retrieved from the given URL. This function can be used directly in SQL queries (see Simple HTTP Fetches and Simple HTTP Fetches in a Single Call Subprograms)

REQUEST_PIECES Function

Returns a PL/SQL table of 2000-byte pieces of the data retrieved from the given URL (see Simple HTTP Fetches and Simple HTTP Fetches in a Single Call Subprograms)

SET_AUTHENTICATION Procedure

Sets HTTP authentication information in the HTTP request header. The Web server needs this information to authorize the request (see HTTP Requests and HTTP Requests Subprograms)

SET_BODY_CHARSET Procedures

Sets the default character set of the body of all future HTTP requests when the media type is text and the character set is not specified in the Content-Type header (see Session Settings and Session Settings Subprograms)

SET_BODY_CHARSET Procedures

Sets the character set of the request body when the media type is text but the character set is not specified in the Content-Type header (see HTTP Requests and HTTP Requests Subprograms)

SET_BODY_CHARSET Procedures

Sets the character set of the response body when the media type is "text" but the character set is not specified in the "Content-Type" header (see HTTP Responses, HTTP Responses Subprograms, Session Settings and Session Settings Subprograms)

SET_COOKIE_SUPPORT Procedures

Enables or disables support for the HTTP cookies in the request (see HTTP Requests and HTTP Requests Subprograms)

SET_DETAILED_EXCP_SUPPORT Procedure

Sets whether or not future HTTP requests will support HTTP cookies; sets the maximum number of cookies maintained in the current database user session (see Session Settings and Session Settings Subprograms)

SET_DETAILED_EXCP_SUPPORT Procedure

Sets the UTL_HTTP package to raise a detailed exception (see Session Settings and Session Settings Subprograms)

SET_FOLLOW_REDIRECT Procedures

Sets the maximum number of times UTL_HTTP follows the HTTP redirect instruction in the HTTP response to this request in the GET_RESPONSE function (see HTTP Requests and HTTP Requests Subprograms)

SET_HEADER Procedure

Sets the maximum number of times UTL_HTTP follows the HTTP redirect instruction in the HTTP responses to future requests in the get_response function (see Session Settings and Session Settings Subprograms)

SET_HEADER Procedure

Sets an HTTP request header. The request header is sent to the Web server as soon as it is set (see HTTP Requests and HTTP Requests Subprograms)

SET_PERSISTENT_CONN_SUPPORT Procedure

Enables or disables support for the HTTP 1.1 persistent-connection in the request (see HTTP Requests and HTTP Requests Subprograms)

SET_PROXY Procedure

Sets the proxy to be used for requests of HTTP or other protocols (see Session Settings and Session Settings Subprograms)

SET_RESPONSE_ERROR_CHECK Procedure

Sets whether or not get_response raises an exception when the Web server returns a status code that indicates an error--a status code in the 4xx or 5xx ranges (see Session Settings and Session Settings Subprograms)

SET_TRANSFER_TIMEOUT Procedure

Sets the timeout value for UTL_HTTP to read the HTTP response from the Web server or proxy server (see Session Settings and Session Settings Subprograms)

SET_WALLET Procedure

Sets the Oracle Wallet used for all HTTP requests over Secured Socket Layer (SSL), that is, HTTPS (see Session Settings and Session Settings Subprograms)

WRITE_LINE Procedure

Writes a text line in the HTTP request body and ends the line with new-line characters (CRLF as defined in UTL_TCP) (see HTTP Requests and HTTP Requests Subprograms)

WRITE_RAW Procedure

Writes some binary data in the HTTP request body (see HTTP Requests and HTTP Requests Subprograms)

WRITE_TEXT Procedure

Writes some text data in the HTTP request body (see HTTP Requests and HTTP Requests Subprograms)


ADD_COOKIES Procedure

This procedure adds the cookies maintained by UTL_HTTP.

See Also:

HTTP Cookies and HTTP Cookies Subprograms

Syntax

UTL_HTTP.ADD_COOKIES (
   cookies  IN cookie_table);

Parameters

Table 156-15 ADD_COOKIES Procedure Parameters
Parameter Description

cookies

The cookies to be added.

Usage Notes

The cookies that the package currently maintains are not cleared before new cookies are added.


BEGIN_REQUEST Function

This functions begins a new HTTP request. UTL_HTTP establishes the network connection to the target Web server or the proxy server and sends the HTTP request line. The PL/SQL program continues the request by calling some other interface to complete the request. The URL may contain the username and password needed to authenticate the request to the server. The format is

scheme://[user[:password]@]host[:port]/[...]

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.BEGIN_REQUEST (
   url           IN VARCHAR2,
   method        IN VARCHAR2 DEFAULT 'GET',
   http_version  IN VARCHAR2 DEFAULT NULL)
RETURN req;

Parameters

Table 156-16 BEGIN_REQUEST Function Parameters
Parameter Description

url

The URL of the HTTP request.

method

The method performed on the resource identified by the URL.

http_version

The HTTP protocol version that sends the request. The format of the protocol version is HTTP/major-version.minor-version, where major-version and minor-version are positive numbers. If this parameter is set to NULL, UTL_HTTP uses the latest HTTP protocol version that it supports to send the request. The latest version that the package supports is 1.1 and it can be upgraded to a later version. The default is NULL.

Usage Notes

The URL passed as an argument to this function is not examined for illegal characters, such as spaces, according to URL specification RFC 2396. You should escape those characters with the UTL_URL package to return illegal and reserved characters. URLs should consist of US-ASCII characters only. See Chapter 166, "UTL_URL" for a list of legal characters in URLs. Note that URLs should consist of US-ASCII characters only. The use of non-US-ASCII characters in a URL is generally unsafe.

An Oracle wallet must be set before accessing Web servers over HTTPS. See the set_wallet procedure on how to set up an Oracle wallet.


CLEAR_COOKIES Procedure

This procedure clears all cookies maintained by the UTL_HTTP package.

See Also:

HTTP Cookies and HTTP Cookies Subprograms

Syntax

UTL_HTTP.CLEAR_COOKIES;

CLOSE_PERSISTENT_CONN Procedure

This procedure closes an HTTP persistent connection maintained by the UTL_HTTP package in the current database session.

See Also:

HTTP Persistent Connections and HTTP Persistent Connections Subprograms

Syntax

UTL_HTTP.CLOSE_PERSISTENT_CONN (
   conn  IN connection);

Parameters

Table 156-17 CLOSE_PERSISTENT_CONN Procedure Parameters
Parameter Description

conn

The HTTP persistent connection to close


CLOSE_PERSISTENT_CONNS Procedure

This procedure closes a group of HTTP persistent connections maintained by the UTL_HTTP package in the current database session. This procedure uses a pattern-match approach to decide which persistent connections to close.

To close a group of HTTP persistent connection that share a common property (for example, all connections to a particular host, or all SSL connections), set the particular parameters and leave the rest of the parameters NULL. If a particular parameter is set to NULL when this procedure is called, that parameter will not be used to decide which connections to close.

For example, the following call to the procedure closes all persistent connections to foobar:

UTL_HTTP.CLOSE_PERSISTENT_CONNS(host => 'foobar');

And the following call to the procedure closes all persistent connections through the proxy www-proxy at TCP/IP port 80:

UTL_HTTP.CLOSE_PERSISTENT_CONNS(proxy_host => 'foobar',
                                proxy_port => 80);

And the following call to the procedure closes all persistent connections:

UTL_HTTP.CLOSE_PERSISTENT_CONNS;

See Also:

HTTP Persistent Connections and HTTP Persistent Connections Subprograms

Syntax

UTL_HTTP.CLOSE_PERSISTENT_CONNS (
   host        IN VARCHAR2 DEFAULT NULL,
   port        IN PLS_INTEGER DEFAULT NULL,
   proxy_host  IN VARCHAR2 DEFAULT NULL,
   proxy_port  IN PLS_INTEGER DEFAULT NULL,
   ssl         IN BOOLEAN DEFAULT NULL);

Parameters

Table 156-18 CLOSE_PERSISTENT_CONNS Procedure Parameters
Parameter Description

host

The host for which persistent connections are to be closed

port

The port number for which persistent connections are to be closed

proxy_host

The proxy host for which persistent connections are to be closed

proxy_port

The proxy port for which persistent connections are to be closed

ssl

Close persistent SSL connection

Usage Notes

Connections to the same Web server at different TCP/IP ports are counted individually. The host names of the Web servers are identified as specified in the URL of the original HTTP requests. Therefore, fully qualified host names with domain names will be counted differently from the host names without domain names.

Note that the use of a NULL value in a parameter when this procedure is called means that the caller does not care about its value when the package decides which persistent connection to close. If you want a NULL value in a parameter to match only a NULL value of the parameter of a persistent connection (which is when you want to close a specific persistent connection), you should use the close_persistent_conn procedure that closes a specific persistent connection.


END_REQUEST Procedure

This procedure ends the HTTP request. To terminate the HTTP request without completing the request and waiting for the response, the program can call this procedure. Otherwise, the program should go through the normal sequence of beginning a request, getting the response, and closing the response. The network connection will always be closed and will not be reused.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.END_REQUEST (
   r  IN OUT NOCOPY req);

Parameters

Table 156-19 END_REQUEST Procedure Parameters
Parameter Description

r

The HTTP request


END_RESPONSE Procedure

This procedure ends the HTTP response. It completes the HTTP request and response. Unless HTTP 1.1 persistent connection is used in this request, the network connection is also closed.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.END_RESPONSE (
   r  IN OUT NOCOPY resp);

Parameters

Table 156-20 END_RESPONSE Procedure Parameters
Parameter Description

r

The HTTP response.


GET_AUTHENTICATION Procedure

This procedure retrieves the HTTP authentication information needed for the request to be accepted by the Web server as indicated in the HTTP response header.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.GET_AUTHENTICATION(
   r          IN OUT NOCOPY resp,
   scheme     OUT VARCHAR2,
   realm      OUT VARCHAR2,
   for_proxy  IN BOOLEAN  DEFAULT FALSE);

Parameters

Table 156-21 GET_AUTHENTICATION Procedure Parameters
Parameter Description

r

The HTTP response.

scheme

The scheme for the required HTTP authentication

realm

The realm for the required HTTP authentication

for_proxy

Returns the HTTP authentication information required for the access to the HTTP proxy server instead of the Web server? Default is FALSE.

Usage Notes

When a Web client is unaware that a document is protected, at least two HTTP requests are required for the document to be retrieved. In the first HTTP request, the Web client makes the request without supplying required authentication information; so the request is denied. The Web client can determine the authentication information required for the request to be authorized by calling get_authentication. The Web client makes the second request and supplies the required authentication information with set_authorization. If the authentication information can be verified by the Web server, the request will succeed and the requested document is returned. Before making the request, if the Web client knows that authentication information is required, it can supply the required authentication information in the first request, thus saving an extra request.


GET_BODY_CHARSET Procedure

This procedure retrieves the default character set of the body of all future HTTP requests.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_BODY_CHARSET (
   charset  OUT NOCOPY VARCHAR2);

Parameters

Table 156-22 GET_BODY_CHARSET Procedure Parameters
Parameter Description

charset

The default character set of the body of all future HTTP requests


GET_COOKIE_COUNT Function

This function returns the number of cookies currently maintained by the UTL_HTTP package set by all Web servers.

See Also:

HTTP Cookies and HTTP Cookies Subprograms

Syntax

UTL_HTTP.GET_COOKIE_COUNT 
RETURN PLS_INTEGER;

GET_COOKIE_SUPPORT Procedure

This procedure retrieves the current cookie support settings.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_COOKIE_SUPPORT (
   enable                OUT BOOLEAN,
   max_cookies           OUT PLS_INTEGER,
   max_cookies_per_site  OUT PLS_INTEGER);

Parameters

Table 156-23 GET_COOKIE SUPPORT Procedure Parameters
Parameter Description

enable

Indicates whether future HTTP requests should support HTTP cookies (TRUE) or not (FALSE)

max_cookies

Indicates the maximum total number of cookies maintained in the current session

max_cookies_per_site

Indicates the maximum number of cookies maintained in the current session for each Web site


GET_COOKIES Function

This function returns all the cookies currently maintained by the UTL_HTTP package set by all Web servers.

See Also:

HTTP Cookies and HTTP Cookies Subprograms

Syntax

UTL_HTTP.GET_COOKIES (
   cookies  IN OUT NOCOPY cookie_table);

Parameters

Table 156-24 GET_COOKIES Procedure Parameters
Parameter Description

cookies

The cookies returned


GET_DETAILED_EXCP_SUPPORT Procedure

This procedure checks if the UTL_HTTP package will raise a detailed exception or not.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_DETAILED_EXCP_SUPPORT (
   enable  OUT BOOLEAN);

Parameters

Table 156-25 GET_DETAILED_EXCP_SUPPORT Procedure Parameters
Parameter Description

enable

TRUE if UTL_HTTP raises a detailed exception; otherwise FALSE


GET_DETAILED_SQLCODE Function

This function retrieves the detailed SQLCODE of the last exception raised.

See Also:

Error Conditions and Error Conditions Subprograms

Syntax

UTL_HTTP.GET_DETAILED_SQLCODE 
RETURN PLS_INTEGER;

GET_DETAILED_SQLERRM Function

This function retrieves the detailed SQLERRM of the last exception raised.

See Also:

Error Conditions and Error Conditions Subprograms

Syntax

UTL_HTTP.GET_DETAILED_SQLERRM 
RETURN VARCHAR2;

GET_FOLLOW_REDIRECT Procedure

This procedure retrieves the follow-redirect setting in the current session

See Also:

Session Settings and Session Settings Subprograms

.

Syntax

UTL_HTTP.GET_FOLLOW_REDIRECT (
   max_redirects  OUT PLS_INTEGER);

Parameters

Table 156-26 GET_FOLLOW_REDIRECT Procedure Parameters
Parameter Description

max_redirects

The maximum number of redirections for all future HTTP requests.


GET_HEADER Procedure

This procedure returns the nth HTTP response header name and value returned in the response.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.GET_HEADER (
   r      IN OUT NOCOPY resp,
   n      IN PLS_INTEGER,
   name   OUT NOCOPY VARCHAR2,
   value  OUT NOCOPY VARCHAR2);

Parameters

Table 156-27 GET_HEADER Procedure Parameters
Parameter Description

r

The HTTP response.

n

The nth header to return.

name

The name of the HTTP response header.

value

The value of the HTTP response header.

Usage Notes

If the response body returned by the remote Web server is encoded in chunked transfer encoding format, the trailer headers that are returned at the end of the response body will be added to the response, and the response header count will be updated. You can retrieve the additional headers after the end of the response body is reached and before you end the response.


GET_HEADER_BY_NAME Procedure

This procedure returns the HTTP response header value returned in the response given the name of the header.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.GET_HEADER_BY_NAME(
   r      IN OUT NOCOPY resp,
   name   IN VARCHAR2,
   value  OUT NOCOPY VARCHAR2,
   n      IN PLS_INTEGER DEFAULT 1);

Parameters

Table 156-28 GET_HEADER_BY_NAME Procedure Parameters
Parameter Description

r

The HTTP response

name

The name of the HTTP response header for which the value is to return

value

The value of the HTTP response header.

n

The nth occurrence of an HTTP response header by the specified name to return. The default is 1.

Usage Notes

If the response body returned by the remote Web server is encoded in chunked transfer encoding format, the trailer headers that are returned at the end of the response body will be added to the response, and the response header count will be updated. You can retrieve the additional headers after the end of the response body is reached and before you end the response.


GET_HEADER_COUNT Function

This function returns the number of HTTP response headers returned in the response.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.GET_HEADER_COUNT (
   r  IN OUT NOCOPY resp) 
RETURN PLS_INTEGER;

Parameters

Table 156-29 GET_HEADER_COUNT Function Parameters
Parameter Description

r

The HTTP response

Usage Notes

If the response body returned by the remote Web server is encoded in chunked transfer encoding format, the trailer headers that are returned at the end of the response body will be added to the response, and the response header count will be updated. You can retrieve the additional headers after the end of the response body is reached and before you end the response.


GET_PERSISTENT_CONN_COUNT Function

This function returns the number of network connections currently kept persistent by the UTL_HTTP package to the Web servers.

See Also:

HTTP Persistent Connections and HTTP Persistent Connections Subprograms

Syntax

UTL_HTTP.GET_PERSISTENT_CONN_COUNT 
RETURN PLS_INTEGER;

Usage Notes

Connections to the same Web server at different TCP/IP ports are counted individually. The host names of the Web servers are identified as specified in the URL of the original HTTP requests. Therefore, fully qualified host names with domain names will be counted differently from the host names without domain names.


GET_PERSISTENT_CONN_SUPPORT Procedure

This procedure checks:

Syntax

UTL_HTTP.GET_PERSISTENT_CONN_SUPPORT (
   enable     OUT BOOLEAN,
   max_conns  OUT PLS_INTEGER);

Parameters

Table 156-30 GET_PERSISTENT_CONN_SUPPORT Procedure Parameters
Parameter Description

enable

TRUE if persistent connection support is enabled; otherwise FALSE

max_conns

the maximum number of persistent connections maintained in the current session.


GET_PERSISTENT_CONNS Procedure

This procedure returns all the network connections currently kept persistent by the UTL_HTTP package to the Web servers.

See Also:

HTTP Persistent Connections and HTTP Persistent Connections Subprograms

Syntax

UTL_HTTP.get_persistent_conns (
   connections  IN OUT NOCOPY connection_table);

Parameters

Table 156-31 GET_PERSISTENT_CONNS Procedure Parameters
Parameter Description

connections

The network connections kept persistent

Usage Notes

Connections to the same Web server at different TCP/IP ports are counted individually. The host names of the Web servers are identified as specified in the URL of the original HTTP requests. Therefore, fully qualified host names with domain names will be counted differently from the host names without domain names.


GET_PROXY Procedure

This procedure retrieves the current proxy settings.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_PROXY (
   proxy             OUT NOCOPY VARCHAR2, 
   no_proxy_domains  OUT NOCOPY VARCHAR2);

Parameters

Table 156-32 GET_PROXY Procedure Parameters
Parameter Description

proxy

The proxy (host and an optional port number) currently used by the UTL_HTTP package

no_proxy_domains

The list of hosts and domains for which no proxy is used for all requests.


GET_RESPONSE Function

This function reads the HTTP response. When the function returns, the status line and the HTTP response headers have been read and processed. The status code, reason phrase, and the HTTP protocol version are stored in the response record. This function completes the HTTP headers section.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.GET_RESPONSE (
   r  IN OUT NOCOPY req) 
RETURN resp;

Parameters

Table 156-33 GET_RESPONSE Procedure Parameters
Parameter Description

r

The HTTP response


GET_RESPONSE_ERROR_CHECK Procedure

This procedure checks if the response error check is set or not.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_RESPONSE_ERROR_CHECK (
   enable  OUT BOOLEAN);

Parameters

Table 156-34 GET_RESPONSE_ERROR_CHECK Procedure Parameters
Parameter Description

enable

TRUE if the response error check is set; otherwise FALSE


GET_TRANSFER_TIMEOUT Procedure

This procedure retrieves the default timeout value for all future HTTP requests.
See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.GET_TRANSFER_TIMEOUT (
   timeout  OUT PLS_INTEGER);

Parameters

Table 156-35 GET_TRANSFER_TIMEOUT Procedure Parameters
Parameter Description

timeout

The network transfer timeout value in seconds.


READ_LINE Procedure

This procedure reads the HTTP response body in text form until the end of line is reached and returns the output in the caller-supplied buffer. The end of line is as defined in the function read_line of UTL_TCP. The end_of_body exception will be raised if the end of the HTTP response body is reached. Text data is automatically converted from the response body character set to the database character set.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.READ_LINE(
   r            IN OUT NOCOPY resp,
   data         OUT NOCOPY  VARCHAR2 CHARACTER SET ANY_CS,
   remove_crlf  IN  BOOLEAN DEFAULT FALSE);

Parameters

Table 156-36 READ_LINE Procedure Parameters
Parameter Description

r

The HTTP response.

data

The HTTP response body in text form

remove_crlf

Removes the newline characters if set to TRUE

Usage Notes

The UTL_HTTP package supports HTTP 1.1 chunked transfer-encoding. When the response body is returned in chunked transfer-encoding format as indicated in the response header, the package automatically decodes the chunks and returns the response body in de-chunked format.

If transfer timeout is set in the request of this response, read_line waits for each data packet to be ready to read until timeout occurs. If it occurs, this procedure stops reading and returns all the data read successfully. If no data is read successfully, the transfer_timeout exception is raised. The exception can be handled and the read operation can be retried later.

If a partial multibyte character is found at the end of the response body, read_line stops reading and returns all the complete multibyte characters read successfully. If no complete character is read successfully, the partial_multibyte_char exception is raised. The exception can be handled and the bytes of that partial multibyte character can be read as binary by the read_raw procedure. If a partial multibyte character is seen in the middle of the response body because the remaining bytes of the character have not arrived and read timeout occurs, the transfer_timeout exception is raised instead. The exception can be handled and the read operation can be retried later.

When the "Content-Type" response header specifies the character set of the response body and the character set is unknown or unsupported by Oracle, the "ORA-01482: unsupported character set" exception is raised if you try to read the response body as text. You can either read the response body as binary using the READ_RAW procedure, or set the character set of the response body explicitly using the SET_BODY_CHARSET procedure and read the response body as text again.


READ_RAW Procedure

This procedure reads the HTTP response body in binary form and returns the output in the caller-supplied buffer. The end_of_body exception will be raised if the end of the HTTP response body is reached.

See Also:

HTTP Responses and HTTP Responses Subprograms

.

Syntax

UTL_HTTP.READ_RAW(
   r     IN OUT NOCOPY resp,
   data  OUT NOCOPY RAW,
   len   IN PLS_INTEGER DEFAULT NULL);

Parameters

Table 156-37 READ_RAW Procedure Parameters
Parameter Description

r

The HTTP response.

data

The HTTP response body in binary form

len

The number of bytes of data to read. If len is NULL, this procedure will read as much input as possible to fill the buffer allocated in data. The actual amount of data returned may be less than that specified if not much data is available before the end of the HTTP response body is reached or the transfer_timeout amount of time has elapsed. The default is NULL

Usage Notes

The UTL_HTTP package supports HTTP 1.1 chunked transfer-encoding. When the response body is returned in chunked transfer-encoding format as indicated in the response header, the package automatically decodes the chunks and returns the response body in de-chunked format.

If transfer timeout is set in the request of this response, read_raw waits for each data packet to be ready to read until timeout occurs. If it occurs, read_raw stops reading and returns all the data read successfully. If no data is read successfully, the transfer_timeout exception is raised. The exception can be handled and the read operation can be retried later.


READ_TEXT Procedure

This procedure reads the HTTP response body in text form and returns the output in the caller-supplied buffer. The end_of_body exception will be raised if the end of the HTTP response body is reached. Text data is automatically converted from the response body character set to the database character set.

See Also:

HTTP Responses and HTTP Responses Subprograms

Syntax

UTL_HTTP.READ_TEXT(
   r     IN OUT NOCOPY resp,
   data  OUT NOCOPY VARCHAR2 CHARACTER SET ANY_CS,
   len   IN PLS_INTEGER DEFAULT NULL);

Parameters

Table 156-38 READ_TEXT Procedure Parameters
Parameter Description

r

The HTTP response.

data

The HTTP response body in text form

len

The maximum number of characters of data to read. If len is NULL, this procedure will read as much input as possible to fill the buffer allocated in data. The actual amount of data returned may be less than that specified if little data is available before the end of the HTTP response body is reached or the transfer_timeout amount of time has elapsed. The default is NULL.

Usage Notes

The UTL_HTTP package supports HTTP 1.1 chunked transfer-encoding. When the response body is returned in chunked transfer-encoding format as indicated in the response header, the package automatically decodes the chunks and returns the response body in de-chunked format.

If transfer timeout is set in the request of this response, read_text waits for each data packet to be ready to read until timeout occurs. If it occurs, this procedure stops reading and returns all the data read successfully. If no data is read successfully, the transfer_timeout exception is raised. The exception can be handled and the read operation can be retried later.

If a partial multibyte character is found at the end of the response body, read_text stops reading and returns all the complete multibyte characters read successfully. If no complete character is read successfully, the partial_multibyte_char exception is raised. The exception can be handled and the bytes of that partial multibyte character can be read as binary by the read_raw procedure. If a partial multibyte character is seen in the middle of the response body because the remaining bytes of the character have not arrived and read timeout occurs, the transfer_timeout exception is raised instead. The exception can be handled and the read operation can be retried later.

When the "Content-Type" response header specifies the character set of the response body and the character set is unknown or unsupported by Oracle, the "ORA-01482: unsupported character set" exception is raised if you try to read the response body as text. You can either read the response body as binary using the READ_RAW procedure, or set the character set of the response body explicitly using the SET_BODY_CHARSET procedure and read the response body as text again.


REQUEST Function

This function returns up to the first 2000 bytes of data retrieved from the given URL. This function can be used directly in SQL queries. The URL may contain the username and password needed to authenticate the request to the server. The format is

scheme://[user[:password]@]host[:port]/[...]

You can define a username/password for the proxy to be specified in the proxy string. The format is

[http://][user[:password]@]host[:port][/]

See Also:

Simple HTTP Fetches and Simple HTTP Fetches in a Single Call Subprograms

Syntax

UTL_HTTP.REQUEST (
   url              IN VARCHAR2,
   proxy            IN VARCHAR2 DEFAULT NULL, 
   wallet_path      IN VARCHAR2 DEFAULT NULL,
   wallet_password  IN VARCHAR2 DEFAULT NULL)
RETURN VARCHAR2;

Pragmas

pragma restrict_references (request, wnds, rnds, wnps, rnps);

Parameters

Table 156-39 REQUEST Function Parameters
Parameter Description

url

Uniform resource locator.

proxy

(Optional) Specifies a proxy server to use when making the HTTP request. See SET_PROXY for the full format of the proxy setting.

wallet_path

(Optional) Specifies a client-side wallet. The client-side wallet contains the list of trusted certificate authorities required for HTTPS request. The format of wallet_path on a PC is, for example, file:c:\WINNT\Profiles\<username>\WALLETS, and in Unix is, for example, file:/home/<username>/wallets

When the UTL_HTTP package is executed in the Oracle database server, the wallet is accessed from the database server. Therefore, the wallet path must be accessible from the database server. See set_wallet for a description on how to set up an Oracle wallet. Non-HTTPS requests do not require an Oracle wallet.

wallet_password

(Optional) Specifies the password required to open the wallet.

Return Values

The return type is a string of length 2000 or less, which contains up to the first 2000 bytes of the HTML result returned from the HTTP request to the argument URL.

Exceptions

INIT_FAILED
REQUEST_FAILED

Usage Notes

The URL passed as an argument to this function is not examined for illegal characters, for example, spaces, according to URL specification RFC 2396. The caller should escape those characters with the UTL_URL package. See the comments of the package for the list of legal characters in URLs. Note that URLs should consist of US-ASCII characters only. The use of non-US-ASCII characters in a URL is generally unsafe.

Please see the documentation of the function set_wallet on the use of an Oracle wallet, which is required for accessing HTTPS Web servers.

Unless response error check is turned on, this function does not raise an exception when a 4xx or 5xx response is received from the Web server. Instead, it returns the formatted error message from the Web server:

<HTML> 
<HEAD> 
<TITLE>Error Message</TITLE> 
</HEAD> 
<BODY> 
<H1>Fatal Error 500</H1> 
Can't Access Document:  http://home.nothing.comm. 
<P> 
<B>Reason:</B> Can't locate remote host:  home.nothing.comm. 
<P> 
<P><HR> 
<ADDRESS><A HREF="http://www.w3.org"> 
CERN-HTTPD3.0A</A></ADDRESS> 
</BODY> 
</HTML> 

Examples

SQLPLUS> SELECT utl_http.request('http://www.my-company.com/') FROM dual;
UTL_HTTP.REQUEST('HTTP://WWW.MY-COMPANY.COM/')                         
<html>
<head><title>My Company Home Page</title>
<!--changed Jan. 16, 19
1 row selected.

If you are behind a firewall, include the proxy parameter. For example, from within the Oracle firewall, where there might be a proxy server named www-proxy.my-company.com:

SQLPLUS> SELECT 
utl_http.request('http://www.my-company.com', 'www-proxy.us.my-company.com') 
FROM dual;

REQUEST_PIECES Function

This function returns a PL/SQL table of 2000-byte pieces of the data retrieved from the given URL. You can define a username/password for the proxy to be specified in the proxy string. The format is

[http://][user[:password]@]host[:port][/] 

See Also:

Simple HTTP Fetches and Simple HTTP Fetches in a Single Call Subprograms

Syntax

type html_pieces is table of varchar2(2000) index by binary_integer;

UTL_HTTP.REQUEST_PIECES (
   url             IN VARCHAR2,
   max_pieces      IN NATURAL DEFAULT 32767,
   proxy           IN VARCHAR2 DEFAULT NULL,
   wallet_path     IN VARCHAR2 DEFAULT NULL,
   wallet_password IN VARCHAR2 DEFAULT NULL)
RETURN html_pieces;

Pragmas

pragma restrict_references (request_pieces, wnds, rnds, wnps, rnps);

Parameters

Table 156-40 REQUEST_PIECES Function Parameters
Parameter Description

url

Uniform resource locator.

max_pieces

(Optional) The maximum number of pieces (each 2000 characters in length, except for the last, which may be shorter), that REQUEST_PIECES should return. If provided, then that argument should be a positive integer.

proxy

(Optional) Specifies a proxy server to use when making the HTTP request. See SET_PROXY for the full format of the proxy setting.

wallet_path

(Optional) Specifies a client-side wallet. The client-side wallet contains the list of trusted certificate authorities required for HTTPS request.

The format of wallet_path on a PC is, for example, file:c:\WINNT\Profiles\<username>\WALLETS, and in Unix is, for example, file:/home/<username>/wallets. When the UTL_HTTP package is executed in the Oracle database server, the wallet is accessed from the database server. Therefore, the wallet path must be accessible from the database server.

See set_wallet for the description on how to set up an Oracle wallet. Non-HTTPS requests do not require an Oracle wallet.

wallet_password

(Optional) Specifies the password required to open the wallet.

Return Values

REQUEST_PIECES returns a PL/SQL table of type UTL_HTTP.HTML_PIECES. Each element of that PL/SQL table is a string of maximum length 2000. The elements of the PL/SQL table returned by REQUEST_PIECES are successive pieces of the data obtained from the HTTP request to that URL.

Exceptions

INIT_FAILED
REQUEST_FAILED

Usage Notes

The URL passed as an argument to this function will not be examined for illegal characters, for example, spaces, according to URL specification RFC 2396. The caller should escape those characters with the UTL_URL package. See the comments of the package for the list of legal characters in URLs. Note that URLs should consist of US-ASCII characters only. The use of non-US-ASCII characters in a URL is generally unsafe.

Each entry of the PL/SQL table (the "pieces") returned by this function may not be filled to their fullest capacity. The function may start filling the data in the next piece before the previous "piece" is totally full.

Please see the documentation of the function set_wallet on the use of an Oracle wallet, which is required for accessing HTTPS Web servers.

Unless response error check is turned on, this function does not raise an exception when a 4xx or 5xx response is received from the Web server. Instead, it returns the formatted error message from the Web server:

<HTML> 
<HEAD> 
<TITLE>Error Message</TITLE> 
</HEAD> 
<BODY> 
<H1>Fatal Error 500</H1> 
Can't Access Document:  http://home.nothing.comm. 
<P> 
<B>Reason:</B> Can't locate remote host:  home.nothing.comm. 
<P> 
<P><HR> 
<ADDRESS><A HREF="http://www.w3.org"> 
CERN-HTTPD3.0A</A></ADDRESS> 
</BODY> 
</HTML>

Examples

SET SERVEROUTPUT ON 


DECLARE 
   x   utl_http.html_pieces; 
   len PLS_INTEGER; 
BEGIN 
   x := utl_http.request_pieces('http://www.oracle.com/', 100); 
   dbms_output.put_line(x.count || ' pieces were retrieved.'); 
   dbms_output.put_line('with total length '); 
   IF x.count < 1 THEN 
      dbms_output.put_line('0'); 
  ELSE 
   len := 0; 
   FOR i in 1..x.count LOOP 
      len := len + length(x(i)); 
   END LOOP; 
   dbms_output.put_line(i); 
  END IF; 
END; 
/ 
-- Output 
Statement processed. 
4 pieces were retrieved. 
with total length 
7687 

SET_AUTHENTICATION Procedure

This procedure sets HTTP authentication information in the HTTP request header. The Web server needs this information to authorize the request.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.SET_AUTHENTICATION(
   r         IN OUT NOCOPY req,
   username  IN VARCHAR2,
   password  IN VARCHAR2,
   scheme    IN VARCHAR2 DEFAULT 'Basic',
   for_proxy IN BOOLEAN  DEFAULT FALSE);

Parameters

Table 156-41 SET_AUTHENTICATION Procedure Parameters
Parameter Description

r

The HTTP request

username

The username for the HTTP authentication

password

The password for the HTTP authentication

scheme

The HTTP authentication scheme. The default, BASIC, denotes the HTTP Basic Authentication scheme.

for_proxy

Identifies if the HTTP authentication information is for access to the HTTP proxy server instead of the Web server. Default is FALSE.

Usage Notes

Only the HTTP Basic Authentication scheme is supported.


SET_BODY_CHARSET Procedures

This procedure is overloaded. The description of different functionalities is located alongside the syntax declarations.

See Also:

Syntax

Sets the default character set of the body of all future HTTP requests when the media type is text and the character set is not specified in the Content-Type header. Following the HTTP protocol standard specification, if the media type of a request or a response is text, but the character set information is missing in the Content-Type header, the character set of the request or response body should default to ISO-8859-1. A response created for a request inherits the default body character set of the request instead of the body character set of the current session. The default body character set is ISO-8859-1 in a database user session. The default body character set setting affects only future requests and has no effect on existing requests. After a request is created, the body character set can be changed by using the other SET_BODY_CHARSET procedure that operates on a request:

UTL_HTTP.SET_BODY_CHARSET (
   charset  IN VARCHAR2 DEFAULT NULL);

Sets the character set of the request body when the media type is text but the character set is not specified in the Content-Type header. According to the HTTP protocol standard specification, if the media type of a request or a response is "text" but the character set information is missing in the Content-Type header, the character set of the request or response body should default to "ISO-8859-1". Use this procedure to change the default body character set a request inherits from the session default setting:

UTL_HTTP.SET_BODY_CHARSET(
   r        IN OUT NOCOPY req,
   charset  IN VARCHAR2 DEFAULT NULL);

Sets the character set of the response body when the media type is "text" but the character set is not specified in the "Content-Type" header. For each the HTTP protocol standard specification, if the media type of a request or a response is "text" but the character set information is missing in the "Content-Type" header, the character set of the request or response body should default to "ISO-8859-1". Use this procedure to change the default body character set a response inherits from the request:

UTL_HTTP.SET_BODY_CHARSET(
   r        IN OUT NOCOPY resp,
   charset  IN VARCHAR2 DEFAULT NULL);

Parameters

Table 156-42 SET_BODY_CHARSET Procedure Parameters
Parameter Description

r

The HTTP response.

charset

The default character set of the response body. The character set can be in Oracle or Internet Assigned Numbers Authority (IANA) naming convention. If charset is NULL, the database character set is assumed.


SET_COOKIE_SUPPORT Procedures

This procedure is overloaded. The description of different functionalities is located alongside the syntax declarations.

This procedure

See Also:

Syntax

Enables or disables support for the HTTP cookies in the request. Use this procedure to change the cookie support setting a request inherits from the session default setting:

UTL_HTTP.SET_COOKIE_SUPPORT(
   r       IN OUT NOCOPY REQ,
   enable  IN BOOLEAN DEFAULT TRUE);

Sets whether or not future HTTP requests will support HTTP cookies, and the maximum number of cookies maintained in the current database user session:

UTL_HTTP.SET_COOKIE_SUPPORT (
   enable       IN BOOLEAN,
   max_cookies  IN PLS_INTEGER DEFAULT 300,
   max_cookies_per_site  IN PLS_INTEGER DEFAULT 20);

Parameters

Table 156-43 SET_COOKIE_SUPPORT Procedure Parameters
Parameter Description

r

The HTTP request.

enable

Set enable to TRUE to enable HTTP cookie support; FALSE to disable.

max_cookies

Sets the maximum total number of cookies maintained in the current session.

max_cookies_per_site

Sets the maximum number of cookies maintained in the current session for each Web site.

Usage Notes

If cookie support is enabled for an HTTP request, all cookies saved in the current session and applicable to the request are returned to the Web server in the request in accordance with HTTP cookie specification standards. Cookies set in the response to the request are saved in the current session for return to the Web server in the subsequent requests if cookie support is enabled for those requests. If the cookie support is disabled for an HTTP request, no cookies are returned to the Web server in the request and the cookies set in the response to the request are not saved in the current session, although the Set-Cookie HTTP headers can still be retrieved from the response.

Cookie support is enabled by default for all HTTP requests in a database user session. The default setting of the cookie support (enabled versus disabled) affects only the future requests and has no effect on the existing ones. After your request is created, the cookie support setting may be changed by using the other set_cookie_support procedure that operates on a request.

The default maximum number of cookies saved in the current session is 20 for each site and 300 total.

If you lower the maximum total number of cookies or the maximum number of cookies for each Web site, the oldest cookies will be purged first to reduce the number of cookies to the lowered maximum. HTTP cookies saved in the current session last for the duration of the database session only; there is no persistent storage for the cookies. Cookies saved in the current session are not cleared if you disable cookie support.

See "Examples" for how to use get_cookies and add_cookies to retrieve, save, and restore cookies.


SET_DETAILED_EXCP_SUPPORT Procedure

This procedure sets the UTL_HTTP package to raise a detailed exception. By default, UTL_HTTP raises the request_failed exception when an HTTP request fails. Use GET_DETAILED_SQLCODE and GET_DETAILED_SQLEERM for more detailed information about the error.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.SET_DETAILED_EXCP_SUPPORT (
   enable  IN BOOLEAN DEFAULT FALSE);

Parameters

Table 156-44 SET_DETAILED_EXCP_SUPPORT Procedure Parameters
Parameter Description

enable

Asks UTL_HTTP to raise a detailed exception directly if set to TRUE; otherwise FALSE


SET_FOLLOW_REDIRECT Procedures

This procedure sets the maximum number of times UTL_HTTP follows the HTTP redirect instruction in the HTTP response to this request, or future requests, in the GET_RESPONSE function.

See Also:

Syntax

Use this procedure to set the maximum number of redirections:

UTL_HTTP.SET_FOLLOW_REDIRECT (
   max_redirects  IN PLS_INTEGER DEFAULT 3);

Use this procedure to change the maximum number of redirections a request inherits from the session default setting:

UTL_HTTP.SET_FOLLOW_REDIRECT(
   r              IN OUT NOCOPY req,
   max_redirects  IN PLS_INTEGER DEFAULT 3);

Parameters

Table 156-45 SET_FOLLOW_REDIRECT Procedure Parameters
Parameter Description

r

The HTTP request

max_redirects

The maximum number of redirects. Set to zero to disable redirects.

Usage Notes

If max_redirects is set to a positive number, the GET_RESPONSE Function will automatically follow the redirected URL for the HTTP response status code 301, 302, and 307 for the HTTP HEAD and GET methods, and 303 for all HTTP methods, and retry the HTTP request (the request method will be changed to HTTP GET for the status code 303) at the new location. It follows the redirection until the final, non-redirect location is reached, or an error occurs, or the maximum number of redirections has been reached (to prevent an infinite loop). The URL and method fields in the REQ record will be updated to the last redirected URL and the method used to access the URL. Set the maximum number of redirects to zero to disable automatic redirection.

While it is set not to follow redirect automatically in the current session, it is possible to specify individual HTTP requests to follow redirect instructions the function follow_redirect and vice versa.

The default maximum number of redirections in a database user session is 3. The default value affects only future requests and has no effect on existing requests.

The SET_FOLLOW_REDIRECT procedure must be called before GET_RESPONSE for any redirection to take effect.


SET_HEADER Procedure

This procedure sets an HTTP request header. The request header is sent to the Web server as soon as it is set.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.SET_HEADER (
   r      IN OUT NOCOPY req,
   name   IN VARCHAR2,
   value  IN VARCHAR2);

Parameters

Table 156-46 SET_HEADER Procedure Parameters
Parameter Description

r

The HTTP request

name

The name of the HTTP request header

value

The value of the HTTP request header

Usage Notes

Multiple HTTP headers with the same name are allowed in the HTTP protocol standard. Therefore, setting a header does not replace a prior header with the same name.

If the request is made using HTTP 1.1, UTL_HTTP sets the Host header automatically for you.

When you set the Content-Type header with this procedure, UTL_HTTP looks for the character set information in the header value. If the character set information is present, it is set as the character set of the request body. It can be overridden later by using the set_body_charset procedure.

When you set the Transfer-Encoding header with the value chunked, UTL_HTTP automatically encodes the request body written by the WRITE_TEXT, WRITE_LINE and WRITE_RAW procedures. Note that some HTTP-1.1-based Web servers or CGI programs do not support or accept the request body encoding in the HTTP 1.1 chunked transfer-encoding format.


SET_PERSISTENT_CONN_SUPPORT Procedure

This procedure enables or disables support for the HTTP 1.1 persistent-connection in the request.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.SET_PERSISTENT_CONN_SUPPORT(
   r       IN OUT NOCOPY req,
   enable  IN BOOLEAN DEFAULT FALSE);

Parameters

Table 156-47 SET_PERSISTENT_CONN_SUPPORT Procedure Parameters
Parameter Description

r

The HTTP request

enable

TRUE to keep the network connection persistent. FALSE otherwise.

Usage Notes

If the persistent-connection support is enabled for an HTTP request, the package will keep the network connections to a Web server or the proxy server open in the package after the request is completed properly for a subsequent request to the same server to reuse for each HTTP 1.1 protocol specification. With the persistent connection support, subsequent HTTP requests may be completed faster because the network connection latency is avoided. If the persistent-connection support is disabled for a request, the package will always send the HTTP header "Connection: close" automatically in the HTTP request and close the network connection when the request is completed. This setting has no effect on HTTP requests that follows HTTP 1.0 protocol, for which the network connections will always be closed after the requests are completed.

When a request is being made, the package attempts to reuse an existing persistent connection to the target Web server (or proxy server) if one is available. If none is available, a new network connection will be initiated. The persistent-connection support setting for a request affects only whether the network connection should be closed after a request completes.

Use this procedure to change the persistent-connection support setting a request inherits from the session default setting.

Users should note that while the use of persistent connections in UTL_HTTP may reduce the time it takes to fetch multiple Web pages from the same server, it consumes precious system resources (network connections) in the database server. Also, excessive use of persistent connections may reduce the scalability of the database server when too many network connections are kept open in the database server. Network connections should be kept open only if they will be used immediately by subsequent requests and should be closed immediately when they are no longer needed. Set the default persistent connection support as disabled in the session, and enable persistent connection in individual HTTP requests as shown in "Examples".

The default value of the maximum number of persistent connections in a database session is zero. To truly enable persistent connections, you must also set the maximum number of persistent connections to a positive value or no connections will be kept persistent.

Examples

Using SET_PERSISTENT_CONN_SUPPORT in HTTP Requests

DECLARE
  TYPE vc2_table IS TABLE OF VARCHAR2(256) INDEX BY binary_integer;
  paths vc2_table;

UTL_HTTP.fetch_pages(paths IN vc2_table) AS
    url_prefix VARCHAR2(256) := 'http://www.my-company.com/';
    req   utl_http.req;
    resp  utl_http.resp;
    data  VARCHAR2(1024);
  BEGIN
    FOR i IN 1..paths.count LOOP
      req := utl_http.begin_request(url_prefix || paths(i));

      -- Use persistent connection except for the last request
      IF (i < paths.count) THEN
        utl_http.set_persistent_conn_support(req, TRUE);
      END IF;
  
      resp := utl_http.get_response(req);
  
      BEGIN
        LOOP
          utl_http.read_text(resp, data);
          -- do something with the data
        END LOOP;
      EXCEPTION
        WHEN utl_http.end_of_body THEN
          NULL;
      END;
      utl_http.end_response(resp);
    END LOOP;
  END;

BEGIN
  utl_http.set_persistent_conn_support(FALSE, 1);
  paths(1) := '...';
  paths(2) := '...';
  ...   
  fetch_pages(paths);
END;

SET_PROXY Procedure

This procedure sets the proxy to be used for requests of the HTTP or other protocols, excluding those for hosts that belong to the domain specified in no_proxy_domains.no_proxy_domains is a comma-, semi-colon-, or space-separated list of domains or hosts for which HTTP requests should be sent directly to the destination HTTP server instead of going through a proxy server.

'
See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.SET_PROXY (
   proxy             IN VARCHAR2,
   no_proxy_domains  IN VARCHAR2);

Parameters

Table 156-48 SET_PROXY Procedure Parameters
Parameter Description

proxy

The proxy (host and an optional port number) to be used by the UTL_HTTP package

no_proxy_domains

The list of hosts and domains for which no proxy should be used for all requests.

Usage Notes

The proxy may include an optional TCP/IP port number at which the proxy server listens. The syntax is [http://]host[:port][/], for example, www-proxy.my-company.com:80. If the port is not specified for the proxy, port 80 is assumed.

Optionally, a port number can be specified for each domain or host. If the port number is specified, the no-proxy restriction is only applied to the request at the port of the particular domain or host, for example, corp.my-company.com, eng.my-company.com:80. When no_proxy_domains is NULL and the proxy is set, all requests go through the proxy. When the proxy is not set, UTL_HTTP sends requests to the target Web servers directly.

You can define a username/password for the proxy to be specified in the proxy string. The format is

[http://][user[:password]@]host[:port][/]

If proxy settings are set when the database server instance is started, the proxy settings in the environment variables http_proxy and no_proxy are assumed. Proxy settings set by this procedure override the initial settings.


SET_RESPONSE_ERROR_CHECK Procedure

This procedure sets whether or not get_response raises an exception when the Web server returns a status code that indicates an error--a status code in the 4xx or 5xx ranges. For example, when the requested URL is not found in the destination Web server, a 404 (document not found) response status code is returned.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.SET_RESPONSE_ERROR_CHECK (
   enable  IN BOOLEAN DEFAULT FALSE);

Parameters

Table 156-49 SET_RESPONSE_ERROR_CHECK Procedure Parameters
Parameter Description

enable

TRUE to check for response errors; otherwise FALSE

Usage Notes

If the status code indicates an error--a 4xx or 5xx code--and this procedure is enabled, get_response will raise the HTTP_CLIENT_ERROR or HTTP_SERVER_ERROR exception. If SET_RESPONSE_ERROR_CHECK is set to FALSE, get_response will not raise an exception when the status code indicates an error.

Response error check is turned off by default.

The get_response function can raise other exceptions when SET_RESPONSE_ERROR_CHECK is set to FALSE.


SET_TRANSFER_TIMEOUT Procedure

This procedure sets the default time out value for all future HTTP requests that the UTL_HTTP package should attempt while reading the HTTP response from the Web server or proxy server. This time out value may be used to avoid the PL/SQL programs from being blocked by busy Web servers or heavy network traffic while retrieving Web pages from the Web servers.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.SET_TRANSFER_TIMEOUT (
   timeout  IN PLS_INTEGER DEFAULT 60);

Parameters

Table 156-50 SET_TRANSFER_TIMEOUT Procedure Parameters
Parameter Description

timeout

The network transfer timeout value in seconds.

Usage Notes

The default value of the time out is 60 seconds.


SET_WALLET Procedure

This procedure sets the Oracle wallet used for all HTTP requests over Secured Socket Layer (SSL), namely HTTPS. When the UTL_HTTP package communicates with an HTTP server over SSL, the HTTP server presents its digital certificate, which is signed by a certificate authority, to the UTL_HTTP package for identification purpose. The Oracle wallet contains the list of certificate authorities that are trusted by the user of the UTL_HTTP package. An Oracle wallet is required to make an HTTPS request.

See Also:

Session Settings and Session Settings Subprograms

Syntax

UTL_HTTP.SET_WALLET (
   path      IN VARCHAR2,
   password  IN VARCHAR2 DEFAULT NULL);

Parameters

Table 156-51 SET_WALLET Procedure Parameters
Parameter Description

path

The directory path that contains the Oracle wallet. The format is file:<directory-path>.

The format of wallet_path on a PC is, for example, file:c:\WINNT\Profiles\<username>\WALLETS, and in Unix is, for example, file:/home/<username>/wallets. When the UTL_HTTP package is executed in the Oracle database server, the wallet is accessed from the database server. Therefore, the wallet path must be accessible from the database server.

password

The password needed to open the wallet. A second copy of a wallet in a wallet directory that may be opened without a password. That second copy of the wallet is read-only. If the password is NULL, the UTL_HTTP package will open the second, read-only copy of the wallet instead.

Usage Notes

To set up an Oracle wallet, use the Oracle Wallet Manager to create a wallet. In order for the HTTPS request to succeed, the certificate authority that signs the certificate of the remote HTTPS Web server must be a trust point set in the wallet.

When a wallet is created, it is populated with a set of well-known certificate authorities as trust points. If the certificate authority that signs the certificate of the remote HTTPS Web server is not among the trust points, or the certificate authority has new root certificates, you should obtain the root certificate of that certificate authority and install it as a trust point in the wallet using Oracle Wallet Manager

See Also:

Oracle Advanced Security Administrator's Guide for more information on Wallet Manager


WRITE_LINE Procedure

This procedure writes a text line in the HTTP request body and ends the line with new-line characters (CRLF as defined in UTL_TCP). As soon as some data is sent as the HTTP request body, the HTTP request headers section is completed. Text data is automatically converted from the database character set to the request body character set.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.WRITE_LINE(
   r     IN OUT NOCOPY req,
   data  IN VARCHAR2 CHARACTER SET ANY_CS);

Parameters

Table 156-52 WRITE_LINE Procedure Parameters
Parameter Description

r

The HTTP request

data

The text line to send in the HTTP request body

Usage Notes

An HTTP client must always let the remote Web server know the length of the request body it is sending. If the amount of data is known beforehand, you can set the Content-Length header in the request, where the length of the content is measured in bytes instead of characters. If the length of the request body is not known beforehand, you can send the request body using the HTTP 1.1 chunked transfer-encoding format. The request body is sent in chunks, where the length of each chunk is sent before the chunk is sent. The UTL_HTTP package performs chunked transfer-encoding on the request body transparently when the Transfer-Encoding: chunked header is set. Note that some HTTP-1.1-based Web servers or CGI programs do not support or accept the request body encoding in the HTTP 1.1 chunked transfer-encoding format. See the set_header procedure for details.

If you send the Content-Length header, you should note that the length specified in the header should be the byte-length of the textual request body after it is converted from the database character set to the request body character set. When either one of the two character sets is a multibyte character set, the precise byte-length of the request body in the request body character set cannot be known beforehand. In this case, you can perform the character set conversion explicitly, determine the byte-length of the results, send the Content-Length header, and the results using the write_raw procedure to avoid the automatic character set conversion. Or, if the remove Web server or CGI programs allow, you can send the request body using the HTTP 1.1 chunked transfer-encoding format, where UTL_HTTP handles the length of the chunks transparently.


WRITE_RAW Procedure

This procedure writes some binary data in the HTTP request body. As soon as some data is sent as the HTTP request body, the HTTP request headers section is completed.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.WRITE_RAW(
   r     IN OUT NOCOPY req,
   data  IN RAW);

Parameters

Table 156-53 WRITE_RAW Procedure Parameters
Parameter Description

r

The HTTP request

data

The binary data to send in the HTTP request body

Usage Notes

An HTTP client must always let the remote Web server know the length of the request body it is sending. If the amount of data is known beforehand, you can set the Content-Length header in the request, where the length of the content is measured in bytes instead of characters. If the length of the request body is not known beforehand, you can send the request body using the HTTP 1.1 chunked transfer-encoding format. The request body is sent in chunks, where the length of each chunk is sent before the chunk is sent. UTL_HTTP performs chunked transfer-encoding on the request body transparently when the Transfer-Encoding: chunked header is set. Note that some HTTP-1.1-based Web servers or CGI programs do not support or accept the request body encoding in the HTTP 1.1 chunked transfer-encoding format. See the set_header procedure for details.


WRITE_TEXT Procedure

This procedure writes some text data in the HTTP request body. As soon as some data is sent as the HTTP request body, the HTTP request headers section is completed. Text data is automatically converted from the database character set to the request body character set.

See Also:

HTTP Requests and HTTP Requests Subprograms

Syntax

UTL_HTTP.WRITE_TEXT(
   r     IN OUT NOCOPY req,
   data  IN VARCHAR2 CHARACTER SET ANY_CS);

Parameters

Table 156-54 WRITE_TEXT Procedure Parameters
Parameter Description

r

The HTTP request

data

The text data to send in the HTTP request body

Usage Notes

An HTTP client must always let the remote Web server know the length of the request body it is sending. If the amount of data is known beforehand, you can set the Content-Length header in the request, where the length of the content is measured in bytes instead of characters. If the length of the request body is not known beforehand, you can send the request body using the HTTP 1.1 chunked transfer-encoding format. The request body is sent in chunks, where the length of each chunk is sent before the chunk is sent. UTL_HTTP performs chunked transfer-encoding on the request body transparently when the Transfer-Encoding: chunked header is set. Note that some HTTP-1.1-based Web servers or CGI programs do not support or accept the request body encoding in the HTTP 1.1 chunked transfer-encoding format. See the set_header procedure for details.

If you send the Content-Length header, you should note that the length specified in the header should be the byte-length of the textual request body after it is converted from the database character set to the request body character set. When either one of the two character sets is a multibyte character set, the precise byte-length of the request body in the request body character set cannot be known beforehand. In this case, you can perform the character set conversion explicitly, determine the byte-length of the results, send the Content-Length header, and the results using the write_raw procedure to avoid the automatic character set conversion. Or, if the remove Web server or CGI programs allow, you can send the request body using the HTTP 1.1 chunked transfer-encoding format, where UTL_HTTP handles the length of the chunks transparently.