org.wandora.modules.servlet

Class RequestForwarder

java.lang.Object

org.wandora.modules.AbstractModule

org.wandora.modules.ScriptModule

org.wandora.modules.servlet.AbstractAction

org.wandora.modules.servlet.CachedAction

org.wandora.modules.servlet.RequestForwarder

All Implemented Interfaces:

Module, ActionHandler, ServletModule.RequestListener

public class RequestForwarder
extends CachedAction

Author:

olli

Nested Class Summary

Nested classes/interfaces inherited from class org.wandora.modules.servlet.CachedAction

CachedAction.OutputProvider

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.LinkedHashMap<java.lang.String,java.lang.String>	additionalParams
protected java.lang.String	destinationHost
protected java.lang.String	destinationPath
protected int	destinationPort
protected java.lang.String	destinationProtocol
protected boolean	forwardAllParams
protected java.util.ArrayList<java.lang.String>	forwardParams

Fields inherited from class org.wandora.modules.servlet.CachedAction

cache, caching, threadPool

Fields inherited from class org.wandora.modules.servlet.AbstractAction

actionParamKey, handledActions, httpHeaders, isDefaultAction, replacements, replacementsInitialized, servletModule

Fields inherited from class org.wandora.modules.ScriptModule

engine, initScript, persistentObjects, scriptManager, startScript, stopScript

Fields inherited from class org.wandora.modules.AbstractModule

autoStart, isInitialized, isRunning, logging, loggingModule, moduleManager

Constructor Summary

Constructors

Constructor and Description
RequestForwarder()

Method Summary

Modifier and Type	Method and Description
protected boolean	doOutput(javax.servlet.http.HttpServletRequest req, ModulesServlet.HttpMethod method, java.lang.String action, CachedAction.OutputProvider out, User user) Does the output that might be either cached or returned directly.
protected java.lang.String	getCacheKey(javax.servlet.http.HttpServletRequest req, ModulesServlet.HttpMethod method, java.lang.String action) Should return a string that uniquely identifies this request.
java.util.Collection<Module>	getDependencies(ModuleManager manager) Returns all the modules this module depends on.
protected java.util.LinkedHashMap<java.lang.String,java.lang.String>	getSendParams(javax.servlet.http.HttpServletRequest req)
void	init(ModuleManager manager, java.util.HashMap<java.lang.String,java.lang.Object> settings) Initialises the module.
protected java.lang.String	makeSendParamString(javax.servlet.http.HttpServletRequest req)
protected void	returnOutput(java.io.InputStream cacheIn, javax.servlet.http.HttpServletResponse resp) Writes a page read from an input stream into an HTTP servlet response.

Methods inherited from class org.wandora.modules.servlet.CachedAction

buildCacheKey, handleAction, readMetadata, start, stop, writeMetadata

Methods inherited from class org.wandora.modules.servlet.AbstractAction

addHandledAction, doReplacements, handleRequest, isHandleAction, setActionParamKey, setHttpHeaders

Methods inherited from class org.wandora.modules.ScriptModule

getScriptEngine

Methods inherited from class org.wandora.modules.AbstractModule

isInitialized, isRunning, requireLogging, toString

Methods inherited from class java.lang.Object

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

Field Detail

additionalParams

protected java.util.LinkedHashMap<java.lang.String,java.lang.String> additionalParams

forwardParams

protected java.util.ArrayList<java.lang.String> forwardParams

forwardAllParams

protected boolean forwardAllParams

destinationProtocol

protected java.lang.String destinationProtocol

destinationHost

protected java.lang.String destinationHost

destinationPort

protected int destinationPort

destinationPath

protected java.lang.String destinationPath

Constructor Detail

RequestForwarder

public RequestForwarder()

Method Detail

getDependencies

public java.util.Collection<Module> getDependencies(ModuleManager manager)
                                             throws ModuleException

Description copied from interface: Module

Returns all the modules this module depends on. This method will be called after init and the dependencies are allowed to depend on the parameters passed to init. The modules that this module depends on must be returned as a collection. In addition, if any required module is not present, a MissingDependencyException should be thrown. Typically you will use the requireModule and optionalModule methods of the manager to make sure that the modules exist and add them to the collection. requireModule will automatically throw the exception too if the module is not found whereas optionalModule does not.

Specified by:

getDependencies in interface Module

Overrides:

getDependencies in class CachedAction

Parameters:

manager - The module manager handling this module.

Returns:

A collection of modules this module depends on.

Throws:

ModuleException

init

public void init(ModuleManager manager,
                 java.util.HashMap<java.lang.String,java.lang.Object> settings)
          throws ModuleException

Description copied from interface: Module

Initialises the module. After constructor, this is the first method called in the life cycle of a module. It should not perform anything time consuming or anything with notable outside side effects. It should only read the parameters and initialise the module so that it can later be started. Note that a module being initialised doesn't mean that it necessarily will ever be started.

A ModuleException may be thrown if something vital is missing from the parameters or they are not sensible. In some cases you may not want to throw an exception even if vital initialisation information is missing. If, for example, it is possible that the module is initialised in some other way between the init and the start method calls. A ModuleException may also be thrown at the start method if the module is still not initialised.

Specified by:

init in interface Module

Overrides:

init in class CachedAction

Parameters:

manager - The module manager handling this module. You may keep a reference to it if needed.

Throws:

ModuleException

getSendParams

protected java.util.LinkedHashMap<java.lang.String,java.lang.String> getSendParams(javax.servlet.http.HttpServletRequest req)

makeSendParamString

protected java.lang.String makeSendParamString(javax.servlet.http.HttpServletRequest req)

returnOutput

protected void returnOutput(java.io.InputStream cacheIn,
                            javax.servlet.http.HttpServletResponse resp)
                     throws java.io.IOException

Description copied from class: CachedAction

Writes a page read from an input stream into an HTTP servlet response. The input stream might be coming from a cached file, or directly from the doOutput method if caching is not in use. In any case, the contents of it need to be written to the response object. Note that any HTTP headers must be set before writing anything else.

If you used writeMetadata in doOutput, you have to override this method and use readMetadata correspondingly to read the metadata from the start of the stream. You can then, for example, set any HTTP headers you read from the metadata. After this, you can call this super implementation which will do the rest of the stream copying.

Make absolutely certain that the input stream is closed before returning from this method. Failing to do so may cause the caching service to become locked which can then lock the whole application. It is best to put the contents in a try-finally block and then call cacheIn.close in the finally part. Do this even if you call the super implementation as your code could possibly fail before reaching that part.

Overrides:

returnOutput in class CachedAction

Throws:

java.io.IOException

doOutput

protected boolean doOutput(javax.servlet.http.HttpServletRequest req,
                           ModulesServlet.HttpMethod method,
                           java.lang.String action,
                           CachedAction.OutputProvider out,
                           User user)
                    throws javax.servlet.ServletException,
                           java.io.IOException

Description copied from class: CachedAction

Does the output that might be either cached or returned directly. The OutputProvider is used to get the output stream where the output should be written. Before you get this stream, you may abort the action by returning false but after the output stream is retrieved, you are committed to outputting the page that then might be cached for future use. Therefore you should do all the preparations first, and only then get the output stream when you know that you will be able to output something sensible.

If you opened the output stream using the output provider, you must make sure that the stream is properly closed. It is best to place all your code after this in a try-finally block and close the stream in the finally part. Failing to do this may cause the caching service to become locked, which in turn could potentially lock the whole application.

Specified by:

doOutput in class CachedAction

Throws:

javax.servlet.ServletException

java.io.IOException

getCacheKey

protected java.lang.String getCacheKey(javax.servlet.http.HttpServletRequest req,
                                       ModulesServlet.HttpMethod method,
                                       java.lang.String action)

Description copied from class: CachedAction

Should return a string that uniquely identifies this request. A future request with the same cache key may use the cached copy of the page. If you don't want some requests cached at all, return a null cache key for those pages. You can use the buildCacheKey method to create a cache key out of a map.

Specified by:

getCacheKey in class CachedAction

Parameters:

req - The HTTP request which, result of which is to be cached.

method - The method of the HTTP request.

action - The parsed action parameter from the request.

Returns:

A cache key that uniquely identifies the results of this request being processed.