wt.httpgw
Class HTTPResponseImpl

java.lang.Object
  wt.httpgw.HTTPResponse
      wt.httpgw.HTTPResponseImpl

All Implemented Interfaces:

Externalizable, Serializable, Runnable, CGIConstants

public class HTTPResponseImpl
extends HTTPResponse
implements Externalizable, Runnable, CGIConstants

This class is a carrier of HTTP response information back to an HTTP gateway from a method server. It uses customized serialization code to stream response bodies to the gateway.

Server-side Serialization The server (NetFactor method server) constructs response objects to carry response information back to the gateway. The object contains fields to store response header information, an output stream reference, and a target class and method.

Object serialization stores the RMI marshal stream reference in the object and invokes the target method using Java's reflection API. The target method uses methods on the response object to set response attributes (content-type, status, etc.) and eventually calls a method to retrieve the output stream on which to write the response body. This call causes the response attributes to be written to the marshal stream. When the target method returns, serialization is complete.

Client-side Deserialization The client (HTTP gateway) receives the response object as the return value of a RMI call. It is deserialized before the RMI call completes. In order to support processing of streamed data, the deserialization code looks up the corresponding HTTPGateway object and uses it to send the response directly from the deserialization code.

First the headers are set on the real gateway response, then the content body is forwarded by reading blocks of data from the input stream and writing them to real response output stream until the entire body has been sent.

  Note: Four response headers are set by default:
        Protocol is set to HTTP/1.0;
        Status is set to 200 (OK); and
        Content-Type is set to text/html.
        Expires is set to long ago, the Java epoch - date(0)

        If you need to set other headers or change these defaults,
        you must do so in your response processing PRIOR to calling
        getOutputStream.
 

Supported API: true
Extendable: false

See Also:

Serialized Form

Method Summary

boolean	containsHeader(String s) Checks if the response header is present.
OutputStream	getOutputStream() Called to get the output stream to write the data to.
void	setDateHeader(String s1, long date) Sets a date type response header.
void	setHeader(String s1, String s2) Sets a string type response header.
void	setIntHeader(String s1, int v1) Sets a int type response header.
void	setStatus(int v1) Sets a simple Status response header.
void	setStatus(int v1, String s1) Sets a Status response header.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getOutputStream

public OutputStream getOutputStream()
                             throws IOException

Called to get the output stream to write the data to. It also causes the HTTPResponseHeaders object to be written out to the RMI marshal stream.

Supported API: true

Specified by:

getOutputStream in class HTTPResponse

Returns:

OutputStream for writing response body

Throws:

IOException - if not marshaling response in writeObject. the output stream is null until such time. Also, if the response target class or method is null. There is not a proper business class or method to write the response.

containsHeader

public boolean containsHeader(String s)

Checks if the response header is present.

Supported API: true

Specified by:

containsHeader in class HTTPResponse

Parameters:

s - String the header to search for.

Returns:

A boolean if the header is set.

setHeader

public void setHeader(String s1,
                      String s2)

Sets a string type response header.

Supported API: true

Specified by:

setHeader in class HTTPResponse

Parameters:

s1 - String name of the header

s2 - String value to which header is set

setDateHeader

public void setDateHeader(String s1,
                          long date)

Sets a date type response header.

Supported API: true

Specified by:

setDateHeader in class HTTPResponse

Parameters:

s1 - String name of the header

date - long value to which header is set value is milliseconds since the epoch.

setIntHeader

public void setIntHeader(String s1,
                         int v1)

Sets a int type response header.

Supported API: true

Specified by:

setIntHeader in class HTTPResponse

Parameters:

s1 - String name of the header

v1 - int value to which header is set

setStatus

public void setStatus(int v1)

Sets a simple Status response header.

Supported API: true

Specified by:

setStatus in class HTTPResponse

Parameters:

v1 - Integer Status code

setStatus

public void setStatus(int v1,
                      String s1)

Sets a Status response header.

Supported API: true

Specified by:

setStatus in class HTTPResponse

Parameters:

v1 - Integer Status code

s1 - String Status reason code