com.ibm.wbi.protocol.http.beans
Class FourStepHttpGenerator

com.ibm.wbi.Meg
  |
  +--com.ibm.wbi.Generator
        |
        +--com.ibm.wbi.protocol.http.HttpGenerator
              |
              +--com.ibm.wbi.protocol.http.beans.FourStepHttpGenerator

Direct Known Subclasses:

ErrorPageGenerator, FileGenerator, HtmlGenerator, PageMovedGenerator, ResourceGenerator

public class FourStepHttpGenerator

extends HttpGenerator

This class breaks down the response to an HTTP request into four steps, each of which can be overridden by extending classes.

1. initialize -- called at the beginning of each transaction
2. verify -- checks to see if this request should be handled by this Generator or not.
3. getHeader -- produces the HTTP header string that will be delivered to the browser.
4. writeContent -- writes the HTTP content to the RequestEvent's output stream.

   Fields inherited from class com.ibm.wbi.protocol.http.HttpGenerator

   COPYRIGHT, http

   Fields inherited from class com.ibm.wbi.Meg

   EDITOR, GENERATOR, MONITOR, REQUEST_EDITOR, UNDEFINED

   Constructor Summary

   FourStepHttpGenerator()
   Construct a new four step HTTP generator.

   Method Summary

   protected java.lang.String	getHeader(RequestEvent e) Called third, should return the HTTP response header string.
   void	handleRequest(RequestEvent e) This method is called by the Proxy.
   protected void	initialize(RequestEvent e) Called first, override if you need to prepare for the transaction by setting up some class variables.
   protected boolean	verify(RequestEvent e) Called second, override if you wish to check some set of conditions.
   protected void	writeContent(RequestEvent e) Called fourth, should write the appropriate data into the output stream object on the request event.

   Methods inherited from class com.ibm.wbi.protocol.http.HttpGenerator

   add, addCookie, getContentType, getHttpResponse, getHttpResponseString, getResponseCode, getResponseText, isCache, produceHeader, set, setCache, setContentLength, setContentType, setResponseCode, setResponseText, setServer, writeHeader

   Methods inherited from class com.ibm.wbi.Generator

   getType

   Methods inherited from class com.ibm.wbi.Meg

   forwardRequest, getCondition, getEnabled, getMegProperty, getMegProperty, getMegPropertyKeys, getName, getPlugin, getPriority, getSystemContext, initialize, initialize, isEnabled, isMegApplicable, loadMegResources, run, setCondition, setEnabled, setMegProperty, setName, setPriority, setSystemContext, setup, setup, setup, setup

   Constructor Detail

   FourStepHttpGenerator

   public FourStepHttpGenerator()

   Construct a new four step HTTP generator.

   Method Detail

   initialize

   protected void initialize(RequestEvent e)

   Called first, override if you need to prepare for the transaction by setting up some class variables.

   Parameters:

   e - The request event.

   verify

   protected boolean verify(RequestEvent e)

   Called second, override if you wish to check some set of conditions.

   Returns:

   true to accept this request and handle it [default]
   false to reject this request and let someone else handle it

   getHeader

   protected java.lang.String getHeader(RequestEvent e)

   Called third, should return the HTTP response header string. By default, this returns the HTTP header produced from the parent's HTTPGenerator HTTPResponse object.

   writeContent

   protected void writeContent(RequestEvent e)
                        throws java.io.IOException,
                               RequestRejectedException

   Called fourth, should write the appropriate data into the output stream object on the request event.

   handleRequest

   public void handleRequest(RequestEvent e)
                      throws RequestRejectedException,
                             java.io.IOException

   This method is called by the Proxy. It calls initialize(), verify(), produceHeader() and writeContent() in order.

   Overrides:

   handleRequest in class HttpGenerator

   Throws:

   RequestRejectedException - thrown if verify(RequestEvent) returns false or getHeader(RequestEvent) returns null.

   java.io.IOException - thrown if writing the data has a problem