org.arch4j.webpresentation
Class FrontCommand

java.lang.Object
  |
  +--org.arch4j.webpresentation.FrontCommand

Direct Known Subclasses:

ExceptionFrontCommand, UnknownFrontCommand

public abstract class FrontCommand

extends Object

This class is the root of a hierarchy of classes that implement the Commmand pattern to handle an HTTP request.

Version:

$Revision: 1.1 $

Author:

$Author: rgreinke $

Field Summary

protected javax.servlet.ServletContext	context
protected javax.servlet.http.HttpServletRequest	request
protected javax.servlet.http.HttpServletResponse	response

Constructor Summary

FrontCommand()

Method Summary

abstract String	execute() Execute the command and return the target to forward to.
void	init(javax.servlet.ServletContext context, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Initialize the command object with information from a servlet.
void	setHelperAttribute(Object helper) Put the given helper object into the request.

Methods inherited from class java.lang.Object

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

Field Detail

context

protected javax.servlet.ServletContext context

request

protected javax.servlet.http.HttpServletRequest request

response

protected javax.servlet.http.HttpServletResponse response

Constructor Detail

FrontCommand

public FrontCommand()

Method Detail

init

public void init(javax.servlet.ServletContext context,
                 javax.servlet.http.HttpServletRequest request,
                 javax.servlet.http.HttpServletResponse response)

Initialize the command object with information from a servlet. These variables are stored and are available for subclasses to use.

Parameters:

context - A ServletContext object that contains the context for the application.

request - An HttpServletRequest object that contains the request the client has made of the servlet.

response - An HttpServletResponse object that contains the response the servlet sends to the client.

execute

public abstract String execute()
                        throws javax.servlet.ServletException,
                               IOException

Execute the command and return the target to forward to.

Returns:

A String containing a fully-qualified resource name, which will be forwarded to.

Throws:

javax.servlet.ServletException - If the request could not be handled.

IOException - If an input or output error is detected when the servlet handles the request.

setHelperAttribute

public void setHelperAttribute(Object helper)

Put the given helper object into the request. The attribute name is given by the constant FrontConstants.HELPER_ATTRIBUTE_NAME.

Parameters:

helper - The helper object to put into the request.