Tomcat example source code file (SSIServlet.java)

This example Tomcat source code file (SSIServlet.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

bufferedreader, can't, http, httpservletresponse, httpservletresponse, inputstreamreader, io, ioexception, ioexception, network, printwriter, request, response, servlet, servletexception, servletexception, ssiprocessor, string, string, stringwriter

The Tomcat SSIServlet.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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.URL;
import java.net.URLConnection;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.Globals;
/**
 * Servlet to process SSI requests within a webpage. Mapped to a path from
 * within web.xml.
 * 
 * @author Bip Thelin
 * @author Amy Roh
 * @author Dan Sandberg
 * @author David Becker
 * @version $Revision: 531303 $, $Date: 2007-04-23 02:24:01 +0200 (lun., 23 avr. 2007) $
 */
public class SSIServlet extends HttpServlet {
    /** Debug level for this servlet. */
    protected int debug = 0;
    /** Should the output be buffered. */
    protected boolean buffered = false;
    /** Expiration time in seconds for the doc. */
    protected Long expires = null;
    /** virtual path can be webapp-relative */
    protected boolean isVirtualWebappRelative = false;
    /** Input encoding. If not specified, uses platform default */
    protected String inputEncoding = null;
    /** Output encoding. If not specified, uses platform default */
    protected String outputEncoding = "UTF-8";


    //----------------- Public methods.
    /**
     * Initialize this servlet.
     * 
     * @exception ServletException
     *                if an error occurs
     */
    public void init() throws ServletException {
        
        if (getServletConfig().getInitParameter("debug") != null)
            debug = Integer.parseInt(getServletConfig().getInitParameter("debug"));
        
        isVirtualWebappRelative = 
            Boolean.parseBoolean(getServletConfig().getInitParameter("isVirtualWebappRelative"));
        
        if (getServletConfig().getInitParameter("expires") != null)
            expires = Long.valueOf(getServletConfig().getInitParameter("expires"));
        
        buffered = Boolean.parseBoolean(getServletConfig().getInitParameter("buffered"));
        
        inputEncoding = getServletConfig().getInitParameter("inputEncoding");
        
        if (getServletConfig().getInitParameter("outputEncoding") != null)
            outputEncoding = getServletConfig().getInitParameter("outputEncoding");
        
        if (debug > 0)
            log("SSIServlet.init() SSI invoker started with 'debug'=" + debug);

    }


    /**
     * Process and forward the GET request to our <code>requestHandler()*
     * 
     * @param req
     *            a value of type 'HttpServletRequest'
     * @param res
     *            a value of type 'HttpServletResponse'
     * @exception IOException
     *                if an error occurs
     * @exception ServletException
     *                if an error occurs
     */
    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws IOException, ServletException {
        if (debug > 0) log("SSIServlet.doGet()");
        requestHandler(req, res);
    }


    /**
     * Process and forward the POST request to our
     * <code>requestHandler().
     * 
     * @param req
     *            a value of type 'HttpServletRequest'
     * @param res
     *            a value of type 'HttpServletResponse'
     * @exception IOException
     *                if an error occurs
     * @exception ServletException
     *                if an error occurs
     */
    public void doPost(HttpServletRequest req, HttpServletResponse res)
            throws IOException, ServletException {
        if (debug > 0) log("SSIServlet.doPost()");
        requestHandler(req, res);
    }


    /**
     * Process our request and locate right SSI command.
     * 
     * @param req
     *            a value of type 'HttpServletRequest'
     * @param res
     *            a value of type 'HttpServletResponse'
     */
    protected void requestHandler(HttpServletRequest req,
            HttpServletResponse res) throws IOException, ServletException {
        ServletContext servletContext = getServletContext();
        String path = SSIServletRequestUtil.getRelativePath(req);
        if (debug > 0)
            log("SSIServlet.requestHandler()\n" + "Serving "
                    + (buffered?"buffered ":"unbuffered ") + "resource '"
                    + path + "'");
        // Exclude any resource in the /WEB-INF and /META-INF subdirectories
        // (the "toUpperCase()" avoids problems on Windows systems)
        if (path == null || path.toUpperCase().startsWith("/WEB-INF")
                || path.toUpperCase().startsWith("/META-INF")) {
            res.sendError(HttpServletResponse.SC_NOT_FOUND, path);
            log("Can't serve file: " + path);
            return;
        }
        URL resource = servletContext.getResource(path);
        if (resource == null) {
            res.sendError(HttpServletResponse.SC_NOT_FOUND, path);
            log("Can't find file: " + path);
            return;
        }
        String resourceMimeType = servletContext.getMimeType(path);
        if (resourceMimeType == null) {
            resourceMimeType = "text/html";
        }
        res.setContentType(resourceMimeType + ";charset=" + outputEncoding);
        if (expires != null) {
            res.setDateHeader("Expires", (new java.util.Date()).getTime()
                    + expires.longValue() * 1000);
        }
        req.setAttribute(Globals.SSI_FLAG_ATTR, "true");
        processSSI(req, res, resource);
    }


    protected void processSSI(HttpServletRequest req, HttpServletResponse res,
            URL resource) throws IOException {
        SSIExternalResolver ssiExternalResolver =
            new SSIServletExternalResolver(getServletContext(), req, res,
                    isVirtualWebappRelative, debug, inputEncoding);
        SSIProcessor ssiProcessor = new SSIProcessor(ssiExternalResolver,
                debug);
        PrintWriter printWriter = null;
        StringWriter stringWriter = null;
        if (buffered) {
            stringWriter = new StringWriter();
            printWriter = new PrintWriter(stringWriter);
        } else {
            printWriter = res.getWriter();
        }

        URLConnection resourceInfo = resource.openConnection();
        InputStream resourceInputStream = resourceInfo.getInputStream();
        String encoding = resourceInfo.getContentEncoding();
        if (encoding == null) {
            encoding = inputEncoding;
        }
        InputStreamReader isr;
        if (encoding == null) {
            isr = new InputStreamReader(resourceInputStream);
        } else {
            isr = new InputStreamReader(resourceInputStream, encoding);
        }
        BufferedReader bufferedReader = new BufferedReader(isr);

        long lastModified = ssiProcessor.process(bufferedReader,
                resourceInfo.getLastModified(), printWriter);
        if (lastModified > 0) {
            res.setDateHeader("last-modified", lastModified);
        }
        if (buffered) {
            printWriter.flush();
            String text = stringWriter.toString();
            res.getWriter().write(text);
        }
    }
}