context.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.boot;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.List;
import java.util.prefs.Preferences;

import javax.net.ssl.TrustManager;


/**
 * Whilst SSL-Explorer is largely a standard web application, it has requirements
 * of its environment above and beyond this.
 * <p>
 * Then environment that services these requires is known as the Context. There
 * should be a single instance of the implementation of this interface and it
 * should be registered with {@link com.sslexplorer.boot.ContextHolder#setContext(Context)}.
 * <p>
 * The instance of the context may then be accessed in the web application and
 * boot classes using {@link com.sslexplorer.boot.ContextHolder#getContext()}.
 * <p>
 * The context responsibilities include :-
 * <ul>
 * <li>Service control. I.e. shutdown and restart</li>
 * <li>Provide locations to store configuration, temporary files, logs etc</li>
 * <li>Provide an HTTP server to serve web content and handle custom HTTP connections</li>
 * <li>Provide and manager databases used for storing configuration and SSL-Explorer resources</li>
 * <li>Obfuscating / deobfuscating passwords</li>
 * <li>Configuring the class loader</li>
 * <li>Providing property definitions and values for the <i>Context properties</i>, i.e. those that
 *     are only applicable to this Context implementation</li>
 * </ul>
 * 
 * @author Brett Smith <a href="mailto: [e-mail]">&lt;[e-mail]&gt;</a>
 * @version $Revision: 1.5 $
 */
public interface Context {
    
    /**
     * Get if the context is currently running in setup mode.
     * 
     * @return running in setup mode.
     */
    public boolean isSetupMode();

    /**
     * Get if the context may be restarted. 
     * 
     * @return restart available
     */
    public boolean isRestartAvailableMode();

    /**
     * Shut down the context, possibly restarting when done.
     * 
     * @param restart restart when shutdown complete
     */
    public void shutdown(boolean restart);


    /**
     * Get the current version of SSL-Explorer.
     * 
     * @return current version
     */
    public VersionInfo.Version getVersion();

    /**
     * Get the directory when configuration files are stored.
     * 
     * @return configuration file directory
     */
    public File getConfDirectory();

    /**
     * Get the directory where tempory files are stored
     * 
     * @return temporary directory
     */
    public File getTempDirectory();

    /**
     * Get the directory where logs are stored
     * 
     * @return logs
     */
    public File getLogDirectory();

    /**
     * Get the directory where database files are stored.
     * 
     * @return database files
     */
    public File getDBDirectory();

    /**
     * Get the directory where application extensions are stored.
     * 
     * @return application extension directory
     */
    public File getApplicationDirectory();

    /**
     * Get the main thread.
     * 
     * @return main thread
     */
    public Thread getMainThread();

    /**
     * Add a new location that contains web resources. Web resources include
     * things suchs as HTML files, Images, CSS, JSP etc.
     * <p>
     * When serving content, the containing web server must search any 
     * added resource bases for the requested resource starting with the 
     * first added resource base until something is found.
     * <p>
     * This is a key part of the extension architecture
     * 
     * @param url url to add
     */
    public void addResourceBase(URL url);

    /**
     * Remove a location from the list of locations that contains web
     * resources.
     * 
     * @param url url to remove
     * @see Context#addResourceBase(URL)
     */
    public void removeResourceBase(URL url);

    /**
     * Return the host name on which SSL-Explorer is running.
     * 
     * @return hostname
     */
    public String getHostname();
    
    /**
     * Return the actual port SSL-Explorer is running on. This may be different
     * to the port in the configuration if the server was invoked with the port
     * argument.
     * 
     * @return port server is running on 
     */
    public int getPort();
    
    /**
     * Add a location to the class loader. Any classes found at this location
     * should then made available to all plugins, the core and any JSP pages.
     * 
     * @param u location of classes
     */
    public void addContextLoaderURL(URL u);

    /**
     * Add a custom request handler.
     * 
     * @param requestHandler request handler
     */
    public void registerRequestHandler(RequestHandler requestHandler);

    /**
     * Remove a custom request handler
     * 
     * @param requestHandler request handler
     */
    public void deregisterRequestHandler(RequestHandler requestHandler);

    /**
     * Obfuscate a password in a way that it be de-obfuscated with 
     * {@link #deobfuscatePassword(String)}.
     * 
     * @param password password to obfuscate
     * @return de-obfuscated password
     */
    public String obfuscatePassword(String password);

    /**
     * De-ebfuscate a password that has been obfuscated with 
     * {@link #obfuscatePassword(String)}.
     * 
     * @param password obfuscated password
     * @return deobfuscated password
     */
    public String deobfuscatePassword(String password);
    
    /**
     * Set the trust manager to use for incoming SSL connections.
     *  
     * @param trustManager trust manager to set
     */
    public void setTrustMananger(TrustManager trustManager, boolean require);
    
    /**
     * Get a list of {@link PropertyDefinition} objects for all the 
     * context properties
     * 
     * @return list of context property definitions
     */
    public List getContextPropertyDefinitions();
    
    /**
     * Get a context property. This method is expected to return sensible
     * defaults.
     * 
     * @param key key
     * @return value
     */
    public String getContextProperty(String key);
    
    /**
     * Set a context property.
     * 
     * @param key key
     * @param value value
     * @return old value
     */
    public String setContextProperty(String key, String value);
    
    /**
     * Add a new web application
     * 
     * @param contextPathSpec path (either / or /path/*)
     * @param webApp path to webapp or WAR file
     * @throws IOException on any error
     * @throws Exception 
     */
    public void addWebApp(String contextPathSpec, String webApp) throws Exception;
    
    /**
     * Add a listener to those being notified of events from the <i>Context</i>.
     * 
     * @param contextListener listener to add
     */
    public void addContextListener(ContextListener contextListener);
    
    /**
     * remove a listener from those being notified of events from the <i>Context</i>.
     * 
     * @param contextListener listener to remove
     */
    public void removeContextListener(ContextListener contextListener);
    
    /**
     * Get the root preferences node. Any component of SSL-Explorer core or
     * its plugins may use this to store configuration information.
     * 
     * @return root preferences node
     */
    public Preferences getPreferences();
}