org.apache.tapestry.asset
Class AssetService

java.lang.Object
  org.apache.tapestry.engine.AbstractService
      org.apache.tapestry.asset.AssetService

All Implemented Interfaces:

IEngineService

public class AssetService
extends AbstractService

A service for building URLs to and accessing IAssets. Most of the work is deferred to the IAsset instance.

The retrieval part is directly linked to PrivateAsset. The service responds to a URL that encodes the path of a resource within the classpath. The service(IEngineServiceView, IRequestCycle, ResponseOutputStream) method reads the resource and streams it out.

TBD: Security issues. Should only be able to retrieve a resource that was previously registerred in some way ... otherwise, hackers will be able to suck out the .class files of the application!

Version:

$Id: AssetService.java 244183 2005-03-21 19:30:48Z pferraro $

Author:

Howard Lewis Ship

Constructor Summary

AssetService()

Method Summary

ILink	getLink(IRequestCycle cycle, IComponent component, Object[] parameters) Builds a ILink for a PrivateAsset.
String	getName() Returns the name of the service.
void	service(IEngineServiceView engine, IRequestCycle cycle, ResponseOutputStream output) Retrieves a resource from the classpath and returns it to the client in a binary output stream.

Methods inherited from class org.apache.tapestry.engine.AbstractService

constructLink, getParameters, getServiceContext

Methods inherited from class java.lang.Object

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

Constructor Detail

AssetService

public AssetService()

Method Detail

getLink

public ILink getLink(IRequestCycle cycle,
                     IComponent component,
                     Object[] parameters)

Builds a ILink for a PrivateAsset.

A single parameter is expected, the resource path of the asset (which is expected to start with a leading slash).

Parameters:

cycle - Defines the request cycle being processed.

component - The component requesting the URL. Generally, the service context is established from the component.

parameters - Additional parameters specific to the component requesting the EngineServiceLink.

Returns:

The URL for the service. The URL will have to be encoded via HttpServletResponse.encodeURL(java.lang.String).

getName

public String getName()

Description copied from interface: IEngineService

Returns the name of the service.

service

public void service(IEngineServiceView engine,
                    IRequestCycle cycle,
                    ResponseOutputStream output)
             throws IOException

Retrieves a resource from the classpath and returns it to the client in a binary output stream.

TBD: Security issues. Hackers can download .class files.

Parameters:

engine - a view of the IEngine with additional methods needed by services

cycle - the incoming request

output - stream to which output should ultimately be directed

Throws:

IOException

See Also:

IEngine.service(org.apache.tapestry.request.RequestContext)