componentresourcerequesttarget.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.request.target.resource;

import javax.servlet.http.HttpServletResponse;

import org.apache.wicket.Component;
import org.apache.wicket.IRequestTarget;
import org.apache.wicket.Page;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.RequestListenerInterface;
import org.apache.wicket.Response;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.protocol.http.WebResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * An implementation of IRequestTarget that is used for the IResourceListener event request.
 * 
 * @author jcompagner
 */
public final class ComponentResourceRequestTarget implements IRequestTarget
{
	private static final Logger log = LoggerFactory.getLogger(ComponentResourceRequestTarget.class);

	private final Page page;
	private final Component component;
	private final RequestListenerInterface listener;

	/**
	 * Construct.
	 * 
	 * @param page
	 * @param component
	 * @param listener
	 */
	public ComponentResourceRequestTarget(Page page, Component component,
			RequestListenerInterface listener)
	{
		this.page = page;
		this.component = component;
		this.listener = listener;
	}

	/**
	 * @see org.apache.wicket.IRequestTarget#respond(org.apache.wicket.RequestCycle)
	 */
	public void respond(RequestCycle requestCycle)
	{
		try
		{
			// Invoke the interface method on the component
			listener.getMethod().invoke(component, new Object[] {});
		}
		catch (Exception e)
		{
			Response response = requestCycle.getResponse();
			if (response instanceof WebResponse)
			{
				((WebResponse)response).getHttpServletResponse().setStatus(
						HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
				log.error("error handling resource request for component " + component +
						", on page " + page + ", listener " + listener.getName() + " - " +
						e.getMessage(), e);
				return;
			}
			else
			{
				throw new WicketRuntimeException("method " + listener.getName() + " of " +
						listener.getMethod().getDeclaringClass() + " targetted at component " +
						component + " threw an exception", e);
			}
		}
	}

	/**
	 * @see org.apache.wicket.IRequestTarget#detach(org.apache.wicket.RequestCycle)
	 */
	public void detach(RequestCycle requestCycle)
	{
		page.detach();
	}

	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(Object obj)
	{
		if (obj instanceof ComponentResourceRequestTarget)
		{
			ComponentResourceRequestTarget that = (ComponentResourceRequestTarget)obj;
			return page.equals(that.page) && component.equals(that.component);
		}
		return false;
	}

	/**
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode()
	{
		int result = getClass().hashCode();
		result += page.hashCode();
		result += component.hashCode();
		return 17 * result;
	}

	/**
	 * @see java.lang.Object#toString()
	 */
	public String toString()
	{
		StringBuffer b = new StringBuffer(getClass().getName()).append("@").append(hashCode())
				.append(page).append("->").append(component.getId()).append("->IResourceListener");
		return b.toString();
	}
}