Tomcat example source code file (ResponseIncludeWrapper.java)

This example Tomcat source code file (ResponseIncludeWrapper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

http, httpservletrequest, httpservletresponse, illegalstateexception, io, ioexception, outputstreamwriter, printwriter, printwriter, request, response, responseincludewrapper, responseincludewrapper, servlet, servletoutputstream, servletoutputstream, string, string, throwable

The Tomcat ResponseIncludeWrapper.java source code

/*
 * 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.catalina.ssi;

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

import javax.servlet.ServletContext;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.apache.catalina.util.DateTool;
/**
 * A HttpServletResponseWrapper, used from
 * <code>SSIServletExternalResolver
 * 
 * @author Bip Thelin
 * @author David Becker
 * @version $Revision: 467222 $, $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */
public class ResponseIncludeWrapper extends HttpServletResponseWrapper {
    /**
     * The names of some headers we want to capture.
     */
    private static final String CONTENT_TYPE = "content-type";
    private static final String LAST_MODIFIED = "last-modified";
    protected long lastModified = -1;
    private String contentType = null;

    /**
     * Our ServletOutputStream
     */
    protected ServletOutputStream captureServletOutputStream;
    protected ServletOutputStream servletOutputStream;
    protected PrintWriter printWriter;
    
    private ServletContext context;
    private HttpServletRequest request;


    /**
     * Initialize our wrapper with the current HttpServletResponse and
     * ServletOutputStream.
     * 
     * @param context The servlet context
     * @param request The HttpServletResponse to use
     * @param response The response to use
     * @param captureServletOutputStream The ServletOutputStream to use
     */
    public ResponseIncludeWrapper(ServletContext context, 
    		HttpServletRequest request, HttpServletResponse response,
           ServletOutputStream captureServletOutputStream) {
        super(response);
        this.context = context;
        this.request = request;
        this.captureServletOutputStream = captureServletOutputStream;
    }


    /**
     * Flush the servletOutputStream or printWriter ( only one will be non-null )
     * This must be called after a requestDispatcher.include, since we can't
     * assume that the included servlet flushed its stream.
     */
    public void flushOutputStreamOrWriter() throws IOException {
        if (servletOutputStream != null) {
            servletOutputStream.flush();
        }
        if (printWriter != null) {
            printWriter.flush();
        }
    }


    /**
     * Return a printwriter, throws and exception if a OutputStream already
     * been returned.
     * 
     * @return a PrintWriter object
     * @exception java.io.IOException
     *                if the outputstream already been called
     */
    public PrintWriter getWriter() throws java.io.IOException {
        if (servletOutputStream == null) {
            if (printWriter == null) {
                setCharacterEncoding(getCharacterEncoding());
                printWriter = new PrintWriter(
                        new OutputStreamWriter(captureServletOutputStream,
                                               getCharacterEncoding()));
            }
            return printWriter;
        }
        throw new IllegalStateException();
    }


    /**
     * Return a OutputStream, throws and exception if a printwriter already
     * been returned.
     * 
     * @return a OutputStream object
     * @exception java.io.IOException
     *                if the printwriter already been called
     */
    public ServletOutputStream getOutputStream() throws java.io.IOException {
        if (printWriter == null) {
            if (servletOutputStream == null) {
                servletOutputStream = captureServletOutputStream;
            }
            return servletOutputStream;
        }
        throw new IllegalStateException();
    }
    
    
    /**
     * Returns the value of the <code>last-modified header field. The
     * result is the number of milliseconds since January 1, 1970 GMT.
     *
     * @return the date the resource referenced by this
     *   <code>ResponseIncludeWrapper was last modified, or -1 if not
     *   known.                                                             
     */
    public long getLastModified() {                                                                                                                                                           
        if (lastModified == -1) {
            // javadocs say to return -1 if date not known, if you want another
            // default, put it here
            return -1;
        }
        return lastModified;
    }

    /**
     * Sets the value of the <code>last-modified header field.
     *
     * @param lastModified The number of milliseconds since January 1, 1970 GMT.
     */
    public void setLastModified(long lastModified) {
        this.lastModified = lastModified;
        ((HttpServletResponse) getResponse()).setDateHeader(LAST_MODIFIED,
                lastModified);
    }

    /**
     * Returns the value of the <code>content-type header field.
     *
     * @return the content type of the resource referenced by this
     *   <code>ResponseIncludeWrapper, or null if not known.
     */
    public String getContentType() {
        if (contentType == null) {
            String url = request.getRequestURI();
            String mime = context.getMimeType(url);
            if (mime != null)
            {
                setContentType(mime);
            }
            else
            {
            	// return a safe value
               setContentType("application/x-octet-stream");
            }
        }
        return contentType;
    }
    
    /**
     * Sets the value of the <code>content-type header field.
     *
     * @param mime a mime type
     */
    public void setContentType(String mime) {
        contentType = mime;
        if (contentType != null) {
            getResponse().setContentType(contentType);
        }
    }


    public void addDateHeader(String name, long value) {
        super.addDateHeader(name, value);
        String lname = name.toLowerCase();
        if (lname.equals(LAST_MODIFIED)) {
            lastModified = value;
        }
    }

    public void addHeader(String name, String value) {
        super.addHeader(name, value);
        String lname = name.toLowerCase();
        if (lname.equals(LAST_MODIFIED)) {
            try {
                lastModified = DateTool.rfc1123Format.parse(value).getTime();
            } catch (Throwable ignore) { }
        } else if (lname.equals(CONTENT_TYPE)) {
            contentType = value;
        }
    }

    public void setDateHeader(String name, long value) {
        super.setDateHeader(name, value);
        String lname = name.toLowerCase();
        if (lname.equals(LAST_MODIFIED)) {
            lastModified = value;
        }
    }

    public void setHeader(String name, String value) {
        super.setHeader(name, value);
        String lname = name.toLowerCase();
        if (lname.equals(LAST_MODIFIED)) {
            try {
                lastModified = DateTool.rfc1123Format.parse(value).getTime();
            } catch (Throwable ignore) { }
        }
        else if (lname.equals(CONTENT_TYPE))
        {
            contentType = value;
        }
    }
}