pluginmanager.java

这是linux下ssl vpn的实现程序

/*
 *  SSL-Explorer
 *
 *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
			

package com.sslexplorer.plugin;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.prefs.Preferences;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.sslexplorer.boot.ContextHolder;
import com.sslexplorer.boot.Util;
import com.sslexplorer.boot.VersionInfo;
import com.sslexplorer.core.CoreServlet;
import com.sslexplorer.core.CoreUtil;

public class PluginManager {
    public final static Preferences PREF = ContextHolder.getContext().getPreferences().node("plugin");
    public final static Log log = LogFactory.getLog(PluginManager.class);

    // Plugin status
    public final static int STATUS_UNINITIALIZED = 0;
    public final static int STATUS_STARTED = 1;
    public final static int STATUS_STOPPED = 2;
    public final static int STATUS_ERRORED = 3;

    // Private instance variables
    private ClassLoader classLoader;
    private List pluginDefinitions;
    private HashMap pluginDefinitionMap;
    private List plugins;
    private HashMap pluginMap;
    private boolean stopping;

    public PluginManager() {
        pluginDefinitions = new ArrayList();
        pluginDefinitionMap = new HashMap();
        plugins = new ArrayList();
        pluginMap = new HashMap();

    }

    public void addPluginDefinition(PluginDefinition def) throws IllegalArgumentException {
        PluginDefinition oldDef = (PluginDefinition) pluginDefinitionMap.get(def.getDescriptor().getId());
        if (oldDef != null) {
            pluginDefinitions.remove(oldDef);
        }
        pluginDefinitions.add(def);
        pluginDefinitionMap.put(def.getDescriptor().getId(), def);
        Collections.sort(pluginDefinitions);
    }

    public void init() throws PluginException {
        // Add the plugins to the classpath (unless in dev mode)
        if ("true".equals(System.getProperty("sslexplorer.forceAddPluginClasspath")) || !"true".equalsIgnoreCase(System.getProperty("sslexplorer.useDevConfig", "false"))) {
            for (Iterator i = pluginDefinitions.iterator(); i.hasNext();) {
                PluginDefinition def = (PluginDefinition) i.next();
                for (Iterator j = def.getClassPath().iterator(); j.hasNext();) {
                    URL u = (URL) j.next();
                    ContextHolder.getContext().addContextLoaderURL(u);
                }
                for (Iterator j = def.getNativeDirectories(); j.hasNext();) {
                    File f = (File) j.next();
                    try {
                        CoreUtil.addLibraryPath(f.getAbsolutePath());
                    } catch (IOException e) {
                        log.error("Failed to add native directory " + f.getAbsolutePath() + ". The plugin " + def.getName()
                                        + " may not function correctly.", e);
                    }
                }
            }
        } else {
            log.warn("Running in development mode, so not adding plugin jars to the classpath or native libraries to "
                            + "the library path (you must do this yourself when launching)");
        }

        // Add any additional class path elements
        StringTokenizer t = new StringTokenizer(System.getProperty("sslexplorer.additionalClasspath", ""), ",");
        while (t.hasMoreTokens()) {
            try {
                String sf = t.nextToken();
                File[] f = null;
                if(sf.endsWith("/*.jar")) {
                    f = new File(sf.substring(0, sf.length() - 6)).listFiles(new FileFilter() {
                        public boolean accept(File pathname) {
                            return pathname.getName().toLowerCase().endsWith(".jar");
                        }                        
                    }); 
                }
                else {
                    f = new File[1];
                    f[0] = new File(sf);
                }
                for(int j = 0 ; f != null && j < f.length; j++) {
                    if (f[j].exists() && (f[j].isDirectory() || f[j].getName().toLowerCase().endsWith(".jar"))) {
                        URL u = f[j].toURL();
                        ContextHolder.getContext().addContextLoaderURL(u);
                    }
                }
            } catch (MalformedURLException murle) {
                log.warn("Invalid element in additional classpaths");
            }

        }

        // Load the plugins and check dependencies
        try {
            loadPlugins();
            checkDependencies();

        } catch (Throwable ex) {
            throw new PluginException("Plugin manager failed to initialise. ", ex);
        }
    }

    public void loadPlugins() throws PluginException {
        InputStream in = null;

        try {
            for (Iterator i = pluginDefinitions.iterator(); i.hasNext();) {
                PluginDefinition def = (PluginDefinition) i.next();

                if (log.isInfoEnabled())
                	log.info("Loading plugin " + def.getDescriptor().getId());

                try {
                    PluginVersion reqVersion = null;
                    if (!def.getRequiredHostVersion().equalsIgnoreCase("any")) {
                        PluginVersion hostVersion = new PluginVersion(VersionInfo.getVersion().toString());
                        reqVersion = new PluginVersion(def.getRequiredHostVersion());
                        int dif = reqVersion.compareTo(hostVersion);
                        if (dif > 0)
                            throw new PluginException("This plugin requires that SSL-Explorer  is at least of version "
                                            + reqVersion.toString());
                    }

                    ClassLoader cl = Thread.currentThread().getContextClassLoader();
                    if (cl == null) {
                        cl = getClass().getClassLoader();
                    }

                    Plugin plugin = (Plugin) Class.forName(def.getClassName(), true, cl).newInstance();
                    String resn = plugin.getClass().getName().replace('.', '/') + ".class";
                    if (log.isDebugEnabled())
                    	log.debug("Looking for resource " + resn);
                    URL res = plugin.getClass().getClassLoader().getResource(resn);
                    String resource = "";
                    if (res == null)
                        log.error("Could not locate resource " + resn);
                    else {

                        String n = res.toExternalForm();
                        if (n.startsWith("jar:file:")) {
                            n = n.substring(4);
                            int idx = n.lastIndexOf('!');
                            if (idx != -1)
                                n = n.substring(0, idx);
                            n = n.substring(5);
                            // Windows path?
                            if (n.startsWith("/") && n.length() > 3 && n.charAt(2) == ':' && Character.isLetter(n.charAt(1))
                                            && n.charAt(3) == '/')
                                n = n.substring(1);
                            File f = new File(n);
                            resource = f.getAbsolutePath();
                        }
                        if (log.isDebugEnabled())
                        	log.debug("Resource is " + resource);
                    }
                    plugins.add(plugin);
                    pluginMap.put(def.getDescriptor().getId(), plugin);
                } catch (Throwable t) {
                    log.error("Failed to load plugin " + def.getClassName(), t);
                }
            }
        } finally {
            PluginUtil.closeStream(in);
        }
        Collections.sort(plugins, new Comparator() {
            public int compare(Object arg0, Object arg1) {
                Plugin p0 = (Plugin) arg0;
                Plugin p1 = (Plugin) arg1;
                PluginDefinition def0 = getPluginDefinition(p0);
                PluginDefinition def1 = getPluginDefinition(p1);
                return def0.compareTo(def1);
            }

        });
    }

    private void checkDependencies() {
        List toRemove = new ArrayList();
        for (Iterator i = pluginDefinitions.iterator(); i.hasNext();) {
            PluginDefinition w = (PluginDefinition) i.next();
            if (log.isInfoEnabled())
            	log.info("Checking dependencies for " + w.getDescriptor().getId() + " (order " + w.getOrder() + ")");
            String deps = w.getDependencies();
            if (deps != null) {
            	if (log.isInfoEnabled())
            		log.info("Dependencies for " + w.getDescriptor().getId() + " are " + deps);
                StringTokenizer t = new StringTokenizer(deps, ",");
                while (t.hasMoreTokens()) {
                    String depName = t.nextToken();
                    int idx = depName.indexOf("/");
                    PluginVersion reqDepVersion = null;
                    if (idx != -1) {
                        String depVersionText = depName.substring(idx + 1);
                        if (depVersionText.length() > 0) {
                            reqDepVersion = new PluginVersion(depVersionText);
                        }
                        depName = depName.substring(0, idx);
                    }

                    // First check the plugin exists
                    PluginDefinition dep = getPluginDefinition(depName);
                    if (dep == null) {
                        log.error("Plugin " + w.getDescriptor().getId() + " depends on " + depName + " "
                                        + (reqDepVersion == null ? "" : ("(version " + reqDepVersion.toString() + ") "))
                                        + "which is not installed. This plugin will not be loaded");
                        toRemove.add(w);
                    } else {
                        // Now check the version if correct (if required)
                        if (reqDepVersion != null) {
                            PluginVersion depVersion = new PluginVersion(dep.getDescriptor().getApplicationBundle().getVersion()
                                            .toString());
                            if (depVersion.compareTo(reqDepVersion) < 0) {
                                log.error("Plugin " + w.getDescriptor().getId() + " depends on " + depName + " (version "
                                                + reqDepVersion.toString() + "), but only version " + depVersion
                                                + " is installed. Please upgrade the dependency");