clienthandler.java

一个用java编写的服务器,对于学习网络编程的人来说是个很好的例子

/*
 * This file is part of the QuickServer library 
 * Copyright (C) 2003-2005 QuickServer.org
 *
 * Use, modification, copying and distribution of this software is subject to
 * the terms and conditions of the GNU Lesser General Public License. 
 * You should have received a copy of the GNU LGP License along with this 
 * library; if not, you can download a copy from <http://www.quickserver.org/>.
 *
 * For questions, suggestions, bug-reports, enhancement-requests etc.
 * visit http://www.quickserver.org
 *
 */

package org.quickserver.net.server;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.sql.Connection;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.net.ssl.SSLSocket;
import org.quickserver.util.MyString;

/**
 * Interface that represents client handle in QuickServer.
 * <p> This class is used by {@link QuickServer} to handle each new client 
 * connected. This class is responsible to handle client sockets. It can operate 
 * in both blocking mode and non-blocking mode (java nio) based on its
 * implementation.</p>
 * @author Akshathkumar Shetty
 */
public interface ClientHandler extends Runnable {

    /** 
	 * Adds the ClientEvent. 
	 * @since 1.4.5
	 */
    void addEvent(ClientEvent event);

	/** 
	 * Removes the ClientEvent. 
	 * @since 1.4.5
	 */
	void removeEvent(ClientEvent event);

    void clean();

    /** Closes client socket associated. */
    void closeConnection();

    /**
	 * Force the closing of the client by closing the associated socket.
	 * @since 1.3.3
	 */
    void forceClose() throws IOException;

    /** 
	 * Returns client SelectionKey associated, if any. 
	 * @since 1.4.5
	 */
    Logger getAppLogger();

    /**
	 *Returns the {@link java.io.BufferedInputStream} associated with 
	 * the Client being handled. Can be null if not available at the time of method call. 
	 * @see #getBufferedOutputStream
	 * @since 1.4.6
	 */
    BufferedInputStream getBufferedInputStream();

    /**
	 * Returns the {@link java.io.BufferedOutputStream} associated with 
	 * the Client being handled. Can be null if not available at the time of method call. 
	 * @see #getBufferedInputStream
	 * @since 1.4.6
	 */
    BufferedOutputStream getBufferedOutputStream();

    /**
	 * Returns the {@link java.io.BufferedReader} associated with 
	 * the Client being handled. Note that this is only available under blocking mode. 
	 * @see #getBufferedWriter
	 */
    BufferedReader getBufferedReader();


    /**
     * Returns Charset to be used for String decoding and encoding..
     * @see #setCharset
	 * @since 1.4.5
     */
    String getCharset();

    /**
	 * Returns the date/time when the client socket was assigned to this
	 * ClientHanlder. If no client is currently connected it will return
	 * <code>null</code>
	 * @since 1.3.1
	 */
    Date getClientConnectedTime();

    /**
     * Returns the ClientData object associated with this ClientHandler, 
	 * if not set will return <code>null</code>
	 * @see ClientData
     */
    ClientData getClientData();

    /**
	 * Returns the communication logging flag.
	 * @see #setCommunicationLogging
	 * @since 1.3.2
	 */
    boolean getCommunicationLogging();

    /**
	 * Returns the {@link DataMode} of the ClientHandler for the 
	 * DataType.
	 * @since 1.2
	 */
    DataMode getDataMode(DataType dataType);

    /**
	 * Returns cached socket host ip address.
	 * @since 1.4.5
	 */
    String getHostAddress();

    /**
	 * Returns the {@link java.io.InputStream} associated with 
	 * the Client being handled.
	 */
    InputStream getInputStream();

    /**
	 * Returns the date/time when the client socket last sent a data to this
	 * ClientHanlder. If no client is currently connected it will return
	 * <code>null</code>
	 * @since 1.3.3
	 */
    Date getLastCommunicationTime();

    /**
	 * Returns message to be displayed to the client when maximum 
	 * connection reaches.
	 * @since 1.4.5
	 */
    String getMaxConnectionMsg();

    /**
     * Returns the ClientHandler name
	 * @since 1.4.6
     */
    String getName();

    /**
	 * Returns the {@link java.io.ObjectInputStream} associated with 
	 * the Client being handled.
	 * It will be <code>null</code> if no {@link ClientObjectHandler} 
	 * was set in {@link QuickServer}.
	 * @see #getObjectOutputStream
	 * @since 1.2
	 */
    ObjectInputStream getObjectInputStream();

    /**
	 * Returns the {@link java.io.ObjectOutputStream} associated with 
	 * the Client being handled.
	 * It will be <code>null</code> if no {@link ClientObjectHandler} 
	 * was set in {@link QuickServer}.
	 * @see #getObjectInputStream
	 * @since 1.2
	 */
    ObjectOutputStream getObjectOutputStream();

    /**
	 * Returns the {@link java.io.OutputStream} associated with 
	 * the Client being handled.
	 * @see #setOutputStream
	 */
    OutputStream getOutputStream();

    /** 
	 * Returns client SelectionKey associated, if any. 
	 * @since 1.4.5
	 */
    SelectionKey getSelectionKey();

    /**
     * Returns the QuickServer object that created it.
     */
    QuickServer getServer();

    /** Returns client socket associated. */
    Socket getSocket();

    /** 
	 * Returns client socket channel associated, if any. 
	 * @since 1.4.5
	 */
    SocketChannel getSocketChannel();

    /**
     * Returns the Client socket timeout in milliseconds.
	 * @see #setTimeout
	 * @since 1.4.5
     */
    int getTimeout();

    /**
	 * Associates the ClientHanlder with the client encapsulated by 
	 * <code>theClient</code>.
	 * @param theClient object that encapsulates client socket 
	 *  and its configuration details.
	 */
    void handleClient(TheClient theClient);

    /** 
	 * Checks if this client has the event. 
	 * @since 1.4.5
	 */
    boolean hasEvent(ClientEvent event);

    /**
     * Returns the ClientHandler detailed information.
	 * If ClientData is present and is ClientIdentifiable will return ClientInfo else
	 * it will return Clients InetAddress and port information.
     */
    String info();

    /**
	 * Checks if the passed ClientEvent is the one next for 
	 * processing if a thread is allowed through this object.
	 * @since 1.4.6
	 */
    boolean isClientEventNext(ClientEvent clientEvent);

    /**
	 * Checks if the client is closed.
	 * @since 1.4.1
	 */
    boolean isClosed();
  

    /**
	 * Checks if the client is still connected.
	 * @exception SocketException if Socket is not open.
	 * @since 1.4.5
	 */
    boolean isConnected() throws SocketException;

    /**
	 * Checks if the client is still connected and if socket is open. This is same as isConnected() 
     * but does not throw SocketException.
	 * @since 1.4.6