org.apache.wicket
Class Resource

java.lang.Object
  org.apache.wicket.Resource

All Implemented Interfaces:

Serializable, IClusterable, IRequestListener, IResourceListener

Direct Known Subclasses:

WebResource

public abstract class Resource
extends Object
implements IResourceListener

A Resource is something that implements IResourceListener and provides a getResourceStream() method which returns the raw IResourceStream to be rendered back to the client browser.

Resources themselves do not currently have URLs. Instead, they are referred to by components that have URLs.

Resources can be shared throughout an application by adding them to Application with addResource(Class scope, String name) or addResource(String name). A resource added in such a way is a named resource and is accessible throughout the application via Application.getResource(Class scope, String name) or Application.getResource(String name). The ResourceReference class enables easy access to such resources in a way that is light on clusters.

While resources can be shared between components, it is important to emphasize that components cannot be shared among containers. For example, you can create a button image resource with new DefaultButtonImageResource(...) and store that in the Application with addResource(). You can then assign that logical resource via ResourceReference to several ImageButton components. While the button image resource can be shared between components like this, the ImageButton components in this example are like all other components in Wicket and cannot be shared.

Author:

Jonathan Locke, Johan Compagner, Gili Tzabari, Igor Vaynberg

See Also:

SharedResources, Serialized Form

Field Summary

Fields inherited from interface org.apache.wicket.IResourceListener

INTERFACE

Constructor Summary

protected

Resource() Constructor

Method Summary

protected void	configureResponse(Response response) Allows implementations to do configure the response, like setting headers etc.
protected ValueMap	getParameters()
abstract IResourceStream	getResourceStream() Returns a new IResourceStream that provides all data for the request.
protected void	invalidate() Sets any loaded resource to null, thus forcing a reload on the next request.
boolean	isCacheable()
void	onResourceRequested() THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
Resource	setCacheable(boolean cacheable) Should this resource be cacheable, so will it set the last modified and the some cache headers in the response.
void	setParameters(Map<String,?> parameters) THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.

Methods inherited from class java.lang.Object

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

Constructor Detail

Resource

protected Resource()

Constructor

Method Detail

getResourceStream

public abstract IResourceStream getResourceStream()

Returns a new IResourceStream that provides all data for the request. Despite its name, this method should return a new IResourceStream instance each time it is invoked (otherwise the InputStream returned from the IResourceStream would be at EOF when a second request is handled for the same Resource). The caller must invoke IResourceStream.close() when finished.

Returns:

a new IResourceStream instance for this Resource.

isCacheable

public final boolean isCacheable()

Returns:

boolean True or False if this resource is cacheable

onResourceRequested

public final void onResourceRequested()

THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT CALL IT. Called when a resource is requested.

Specified by:

onResourceRequested in interface IResourceListener

setCacheable

public final Resource setCacheable(boolean cacheable)

Should this resource be cacheable, so will it set the last modified and the some cache headers in the response.

Parameters:

cacheable - boolean if the lastmodified and cache headers must be set.

Returns:

this

setParameters

public final void setParameters(Map<String,?> parameters)

THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!

Parameters:

parameters - Map of query parameters that parameterize this resource

configureResponse

protected void configureResponse(Response response)

Allows implementations to do configure the response, like setting headers etc.

Parameters:

response - the response

getParameters

protected ValueMap getParameters()

Returns:

Any query parameters associated with the request for this resource

invalidate

protected void invalidate()

Sets any loaded resource to null, thus forcing a reload on the next request.