pluginservlet.java

基于Jabber协议的即时消息服务器

/**
 * $Revision: 3067 $
 * $Date: 2005-11-12 22:29:01 -0300 (Sat, 12 Nov 2005) $
 *
 * Copyright (C) 2004-2005 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.wildfire.container;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspC;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.jivesoftware.util.JiveGlobals;
import org.jivesoftware.util.Log;
import org.jivesoftware.util.StringUtils;
import org.xml.sax.SAXException;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import javax.servlet.GenericServlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * The plugin servlet acts as a proxy for web requests (in the admin console)
 * to plugins. Since plugins can be dynamically loaded and live in a different place
 * than normal Wildfire admin console files, it's not possible to have them
 * added to the normal Wildfire admin console web app directory.<p>
 * <p/>
 * The servlet listens for requests in the form <tt>/plugins/[pluginName]/[JSP File]</tt>
 * (e.g. <tt>/plugins/foo/example.jsp</tt>). It also listens for non JSP requests in the
 * form like <tt>/plugins/[pluginName]/images/*.png|gif</tt>,
 * <tt>/plugins/[pluginName]/scripts/*.js|css</tt> or
 * <tt>/plugins/[pluginName]/styles/*.css</tt> (e.g.
 * <tt>/plugins/foo/images/example.gif</tt>).<p>
 * <p/>
 * JSP files must be compiled and available via the plugin's class loader. The mapping
 * between JSP name and servlet class files is defined in [pluginName]/web/web.xml.
 * Typically, this file is auto-generated by the JSP compiler when packaging the plugin.
 * Alternatively, if development mode is enabled for the plugin then the the JSP file
 * will be dynamically compiled using JSPC.
 *
 * @author Matt Tucker
 */
public class PluginServlet extends HttpServlet {

    private static Map<String, GenericServlet> servlets;
    private static PluginManager pluginManager;
    private static ServletConfig servletConfig;

    static {
        servlets = new ConcurrentHashMap<String, GenericServlet>();
    }

    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        servletConfig = config;
    }

    public void service(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        String pathInfo = request.getPathInfo();
        if (pathInfo == null) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
        }
        else {
            try {
                // Handle JSP requests.
                if (pathInfo.endsWith(".jsp")) {
                    if (handleDevJSP(pathInfo, request, response)) {
                        return;
                    }
                    handleJSP(pathInfo, request, response);
                }
                // Handle servlet requests.
                else if (getServlet(pathInfo) != null) {
                    handleServlet(pathInfo, request, response);
                }
                // Handle image/other requests.
                else {
                    handleOtherRequest(pathInfo, response);
                }
            }
            catch (Exception e) {
                Log.error(e);
                response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            }
        }
    }

    /**
     * Registers all JSP page servlets for a plugin.
     *
     * @param manager the plugin manager.
     * @param plugin the plugin.
     * @param webXML the web.xml file containing JSP page names to servlet class file
     *      mappings.
     */
    public static void registerServlets(PluginManager manager, Plugin plugin, File webXML) {
        pluginManager = manager;
        if (!webXML.exists()) {
            Log.error("Could not register plugin servlets, file " + webXML.getAbsolutePath() +
                " does not exist.");
            return;
        }
        // Find the name of the plugin directory given that the webXML file
        // lives in plugins/[pluginName]/web/web.xml
        String pluginName = webXML.getParentFile().getParentFile().getParentFile().getName();
        try {
            // Make the reader non-validating so that it doesn't try to resolve external
            // DTD's. Trying to resolve external DTD's can break on some firewall configurations.
            SAXReader saxReader = new SAXReader(false);
            try {
                saxReader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd",
                    false);
            }
            catch (SAXException e) {
                Log.warn("Error setting SAXReader feature", e);
            }
            Document doc = saxReader.read(webXML);
            // Find all <servlet> entries to discover name to class mapping.
            List classes = doc.selectNodes("//servlet");
            Map<String, Class> classMap = new HashMap<String, Class>();
            for (int i = 0; i < classes.size(); i++) {
                Element servletElement = (Element)classes.get(i);
                String name = servletElement.element("servlet-name").getTextTrim();
                String className = servletElement.element("servlet-class").getTextTrim();
                classMap.put(name, manager.loadClass(plugin, className));
            }
            // Find all <servelt-mapping> entries to discover name to URL mapping.
            List names = doc.selectNodes("//servlet-mapping");
            for (int i = 0; i < names.size(); i++) {
                Element nameElement = (Element)names.get(i);
                String name = nameElement.element("servlet-name").getTextTrim();
                String url = nameElement.element("url-pattern").getTextTrim();
                // Register the servlet for the URL.
                Class servletClass = classMap.get(name);
                if(servletClass == null) {
                    Log.error("Unable to load servlet, " + name + ", servlet-class not found.");
                    continue;
                }
                Object instance = servletClass.newInstance();
                if (instance instanceof GenericServlet) {
                    // Initialize the servlet then add it to the map..
                    ((GenericServlet)instance).init(servletConfig);
                    servlets.put(pluginName + url, (GenericServlet)instance);
                }
                else {
                    Log.warn("Could not load " + (pluginName + url) + ": not a servlet.");
                }
            }
        }
        catch (Throwable e) {
            Log.error(e);
        }
    }

    /**
     * Unregisters all JSP page servlets for a plugin.
     *
     * @param webXML the web.xml file containing JSP page names to servlet class file
     *               mappings.
     */
    public static void unregisterServlets(File webXML) {
        if (!webXML.exists()) {
            Log.error("Could not unregister plugin servlets, file " + webXML.getAbsolutePath() +
                " does not exist.");
            return;
        }
        // Find the name of the plugin directory given that the webXML file
        // lives in plugins/[pluginName]/web/web.xml
        String pluginName = webXML.getParentFile().getParentFile().getParentFile().getName();
        try {
            SAXReader saxReader = new SAXReader(false);
            saxReader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd",
                false);
            Document doc = saxReader.read(webXML);
            // Find all <servelt-mapping> entries to discover name to URL mapping.
            List names = doc.selectNodes("//servlet-mapping");
            for (int i = 0; i < names.size(); i++) {
                Element nameElement = (Element)names.get(i);
                String url = nameElement.element("url-pattern").getTextTrim();
                // Destroy the servlet than remove from servlets map.
                GenericServlet servlet = servlets.get(pluginName + url);
                if (servlet != null) {
                    servlet.destroy();
                }
                servlets.remove(pluginName + url);
                servlet = null;
            }
        }
        catch (Throwable e) {
            Log.error(e);
        }
    }

    /**
     * Handles a request for a JSP page. It checks to see if a servlet is mapped
     * for the JSP URL. If one is found, request handling is passed to it. If no
     * servlet is found, a 404 error is returned.
     *
     * @param pathInfo the extra path info.
     * @param request  the request object.
     * @param response the response object.
     * @throws ServletException if a servlet exception occurs while handling the request.
     * @throws IOException      if an IOException occurs while handling the request.
     */
    private void handleJSP(String pathInfo, HttpServletRequest request,
                           HttpServletResponse response) throws ServletException, IOException {
        // Strip the starting "/" from the path to find the JSP URL.
        String jspURL = pathInfo.substring(1);

        GenericServlet servlet = servlets.get(jspURL);
        if (servlet != null) {
            servlet.service(request, response);
        }
        else {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    /**
     * Handles a request for a Servlet. If one is found, request handling is passed to it.
     * If no servlet is found, a 404 error is returned.
     *
     * @param pathInfo the extra path info.
     * @param request  the request object.
     * @param response the response object.
     * @throws ServletException if a servlet exception occurs while handling the request.
     * @throws IOException      if an IOException occurs while handling the request.
     */
    private void handleServlet(String pathInfo, HttpServletRequest request,
                               HttpServletResponse response) throws ServletException, IOException {
        // Strip the starting "/" from the path to find the JSP URL.
        GenericServlet servlet = getServlet(pathInfo);
        if (servlet != null) {
            servlet.service(request, response);
        }
        else {