servletresponsewrapperinclude.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.jasper.runtime;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletOutputStream;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.jsp.JspWriter;

/**
 * ServletResponseWrapper used by the JSP 'include' action.
 *
 * This wrapper response object is passed to RequestDispatcher.include(), so
 * that the output of the included resource is appended to that of the
 * including page.
 *
 * @author Pierre Delisle
 */

public class ServletResponseWrapperInclude extends HttpServletResponseWrapper {

    /**
     * PrintWriter which appends to the JspWriter of the including page.
     */
    private PrintWriter printWriter;

    private JspWriter jspWriter;

    public ServletResponseWrapperInclude(ServletResponse response, 
					 JspWriter jspWriter) {
	super((HttpServletResponse)response);
	this.printWriter = new PrintWriter(jspWriter);
	this.jspWriter = jspWriter;
    }

    /**
     * Returns a wrapper around the JspWriter of the including page.
     */
    public PrintWriter getWriter() throws IOException {
	return printWriter;
    }

    public ServletOutputStream getOutputStream() throws IOException {
	throw new IllegalStateException();
    }

    /**
     * Clears the output buffer of the JspWriter associated with the including
     * page.
     */
    public void resetBuffer() {
	try {
	    jspWriter.clearBuffer();
	} catch (IOException ioe) {
	}
    }
}