Oracle9i Supplied PL/SQL Packages and Types Reference Release 1 (9.0.1) Part Number A89852-02 |
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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.
The package contains a set of APIs that enables users to write PL/SQL programs that communicate with Web (HTTP) servers. UTL_HTTP
also contains a function that can be used in SQL queries. Besides HTTP, it also supports HTTP over the Secured Socket Layer protocol (SSL), also known as HTTPS, directly or via 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.
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:
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This chapter discusses the following topics:
Table 78-1 lists the defined constants for UTL_HTTP.
Use the following types with UTL_HTTP
.
Use this PL/SQL record type to represent an HTTP request.
TYPE req IS RECORD (url VARCHAR2(32767), method VARCHAR2(64), http_version VARCHAR2(64),);
Table 78-2 shows the parameters for the REQ type.
The information returned in REQ
from the API 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.
This PL/SQL record type is used to represent an HTTP response.
TYPE resp IS RECORD (status_code PLS_INTEGER, reason_phrase VARCHAR2(256), http_version VARCHAR2(64),);
Table 78-3 shows the parameters for the RESP type.
The information returned in RESP
from the API 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.
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.
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;
Table 78-4 shows the fields for the COOKIE and COOKIE_TABLE record types.
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 "Example: Retrieving and Restoring Cookies".
Use this 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.
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;
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