abortwithhttpstatusexception.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.protocol.http.servlet;

import javax.servlet.http.HttpServletResponse;

import org.apache.wicket.AbstractRestartResponseException;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.Response;
import org.apache.wicket.protocol.http.WebResponse;
import org.apache.wicket.request.target.basic.EmptyRequestTarget;


/**
 * Causes Wicket to abort processing and set the specified HTTP status code. An
 * {@link IllegalStateException} will be thrown if HTTP status code could not be set and the
 * optional parameter is specified as false.
 * 
 * This exception can be thrown from a page or a resource.
 * 
 * @author Igor Vaynberg (ivaynberg)
 * @author Gili Tzabari
 * @see HttpServletResponse
 */
public class AbortWithHttpStatusException extends AbstractRestartResponseException
{
	private static final long serialVersionUID = 1L;
	private final int status;

	/**
	 * Constructor
	 * 
	 * @param status
	 *            The http response status code
	 * @param statusCodeOptional
	 *            If true and http status could not be set, an IllegalStateException will be thrown
	 */
	public AbortWithHttpStatusException(int status, boolean statusCodeOptional)
	{
		this.status = status;

		RequestCycle rc = RequestCycle.get();
		if (rc == null)
		{
			if (!statusCodeOptional)
			{
				throw new IllegalStateException(
						"This exception can only be thrown from within request processing cycle");
			}
		}
		else
		{
			Response r = rc.getResponse();
			if (!(r instanceof WebResponse))
			{
				throw new IllegalStateException(
						"This exception can only be thrown when wicket is processing an http request");
			}

			WebResponse wr = (WebResponse)r;
			wr.getHttpServletResponse().setStatus(status);

			// abort any further response processing
			rc.setRequestTarget(EmptyRequestTarget.getInstance());
		}
	}

	/**
	 * @return the response status code
	 */
	public final int getStatus()
	{
		return status;
	}
}