Java Socket 编程——多线程网络聊天程序

本文作者：longlongago     博客地址：http://blog.youkuaiyun.com/longlongago2000

用java进行网络编程确实很方便，很容易上手。这几天用java进行socket编程，收获不少。

首先，进行服务端的编程，作为服务端，编程主要按下面几个步骤进行：

//  1. 创建socket
            ServerSocket ss  =   new  ServerSocket(PortNumber);
            Socket s  =  ss.accept();  // 监听器，产生阻塞，直到有连接才停止阻塞。 

             //  2. 打开输入流、输出流
            OutputStream os  =  s.getOutputStream();
            BufferedOutputStream bos  =   new  BufferedOutputStream(os);
            InputStream is  =  s.getInputStream(); 

             //  3. 根据一定的协议读写数据
             //  服务器 --> 客户
//             os.write("Hello,I am Server!".getBytes());
            bos.write( " Hello,I am Server! " .getBytes());
            bos.flush();  // 注意!! 

             //  服务器 <-- 客户
             byte [] buf  =   new   byte [ 100 ];
             int  len  =  is.read(buf);
            System.out.println( new  String(buf,  0 , len)); 

             //  4. 关系流和Socket
//             os.close();
            bos.close();
            is.close();
            s.close();
            ss.close(); 

 

作为客户端则分为下面几个步骤，其实和服务端差不多，只是少了用ServerSocket进行监听。

//  1. 创建socket
            Socket s  =   new  Socket(InetAddress.getByName( " localhost " ),
                    PortNumber);
             //  2. 打开输入流、输出流
            OutputStream os  =  s.getOutputStream();
            InputStream is  =  s.getInputStream(); 

             //  3. 根据一定的协议读写数据
             //  服务器 --> 客户
             byte [] buf  =   new   byte [ 100 ];
             int  len  =  is.read(buf);
            System.out.println( new  String(buf,  0 , len));
             //  服务器 <-- 客户
            os.write( " Hello,I am Client! " .getBytes()); 

             //  4. 关系流和Socket
            os.close();
            is.close();
            s.close(); 

上面这些只是一个单线程的服务端->客户端的程序，只能进行一次通讯，多次通讯将被告知无法连接。

这时，我们就需要用到进程Thread进行编程，将其改造成多线程聊天程序，可以同时进行多客户端的连接与发送信息。

代码如下：

// Server.java 

import  java.awt. * ;
import  java.net. * ;
import  java.io. * ; 

public   class  Server  extends  Thread  ... {
    ServerSocket skt; 

    Socket Client[]=new Socket[10];;
    Socket Client1=null; 

    int i = 0; 

    TextArea in; 

    int port,k=0,l=0; 

    //BufferedReader theInputStream; 

    PrintStream theOutputStream; 

    //String readin; 

    Face chat; 

    public Server(int port, Face chat) ...{
        try ...{
            this.port = port;
            skt = new ServerSocket(port);
            this.chat = chat;
        } catch (IOException e) ...{
            chat.ta.append(e.toString());
        }
    } 

    public void run() ...{ 

        chat.ta.append("等待连线......"); 

        while (true) ...{
            //System.out.print(""+i+" ");
            try ...{
             

                Client[k] = skt.accept(); /**//* 接收客户连接 */

                //当有客户端连接时就新建一个子线程
                

                if (i < 2) ...{
                    ServerThread server[] = new ServerThread[10];
                     server[k]= new ServerThread(Client[k], this.chat, i);
                     l=server.length;
                     server[k].start();
                    chat.ta.append("客户端" + Client[k].getInetAddress() + "已连线 ");
                    /**//*theInputStream = new BufferedReader(new InputStreamReader(Client
                            .getInputStream()));*/
                    //for(int j=0;j<server.length;j++)
                    theOutputStream = new PrintStream(server[k].getClient().getOutputStream());
                    i = server[k].getI();
                    k++;
                } else ...{
                    //theOutputStream = new PrintStream(null);
                } 

            } catch (SocketException e) ...{
                //chat.ta.append("连线中断！ "); 

                //chat.clientBtn.setEnabled(true);
                //chat.serverBtn.setEnabled(true);
                //chat.tfaddress.setEnabled(true);
                //chat.tfport.setEnabled(true);
                //try { 

                    //skt.close();
                    //Client.close();
                //} catch (IOException err) {
                //    chat.ta.append(err.toString());
                //}
            } catch (IOException e) ...{
                chat.ta.append(e.toString());
            }
        } 

    } 

    public void dataout(String data) ...{
        //for(int j=0;j<l;j++)
        theOutputStream.println(data);
    }
}  

class  ServerThread  extends  Thread  ... {
    ServerSocket skt; 

    Socket client; 

    TextArea in; 

    int port; 

    int i; 

    BufferedReader theInputStream; 

    PrintStream theOutputStream; 

    String readin; 

    Face chat; 

//服务端子线程 

    public ServerThread(Socket s, Face chat, int i) ...{
        this.i = ++i;
        client= s;
        //this.port = port;
        //skt = new ServerSocket(port);
        this.chat = chat; 

    } 

    public int getI() ...{
        return this.i;
    }
    public Socket getClient() ...{
        return this.client;
    }
    public void run() ...{ 

        //chat.ta.append("等待连线......"); 

        try ...{
            //Client = skt.accept(); /* 接收客户连接 */ 

            //chat.ta.append("客户端" + Client.getInetAddress() + "已连线 ");
            theInputStream = new BufferedReader(new InputStreamReader(client
                    .getInputStream()));
            theOutputStream = new PrintStream(Client.getOutputStream()); 

            while (true) ...{
                readin = theInputStream.readLine();
                chat.ta.append(readin + " ");
            } 

        } catch (SocketException e) ...{
            chat.ta.append("连线中断！ "); 

            chat.clientBtn.setEnabled(true);
            chat.serverBtn.setEnabled(true);
            chat.tfaddress.setEnabled(true);
            chat.tfport.setEnabled(true);
            try ...{
                i--;
                skt.close();
                client.close();
            } catch (IOException err) ...{
                chat.ta.append(err.toString());
            }
        } catch (IOException e) ...{
            chat.ta.append(e.toString());
        }
    } 

    public void dataout(String data) ...{
        theOutputStream.println(data);
    }
}  

// Client.java 

import  java.net. * ;
import  java.io. * ;
import  javax.swing.Timer;
class  Client  extends  Thread  ... {
    Socket skt;
    InetAddress host;
    int port; 

    BufferedReader theInputStream;
    PrintStream theOutputStream;
    String readin; 

    Face chat; 

    public Client(String ip, int p, Face chat) ...{
        try ...{
            host = InetAddress.getByName(ip);
            port = p;
            this.chat = chat;
        } catch (IOException e) ...{
            chat.ta.append(e.toString());
        }
    } 

    public void run() ...{
        try ...{
            chat.ta.append("尝试连线......"); 

            skt = new Socket(host, port);
            chat.ta.append("连线成功 "); 

            theInputStream = new BufferedReader(new InputStreamReader(skt
                    .getInputStream())); 

            theOutputStream = new PrintStream(skt.getOutputStream());
            //Timer myTimer = new Timer();
            while (true) ...{
                readin = theInputStream.readLine();
                chat.ta.append(readin + " ");
            }
        } catch (SocketException e) ...{
            chat.ta.append("连线中断！ ");
            chat.clientBtn.setEnabled(true);
            chat.serverBtn.setEnabled(true);
            chat.tfaddress.setEnabled(true);
            chat.tfport.setEnabled(true);
            try ...{
                skt.close();
            } catch (IOException err) ...{
                chat.ta.append(err.toString());
            }
        } catch (IOException e) ...{
            chat.ta.append(e.toString());
        }
    } 

    public void dataout(String data) ...{
        theOutputStream.println(data);
    }
}  

// 软件界面，进行按键监听调用。

// face.java 

import  java.awt. * ;
import  java.awt.event. * ; 

public   class  Face  extends  Frame  ... {
    /** *//**
     * 
     */
    private static final long serialVersionUID = 1L;
    Button clientBtn, serverBtn;
    TextArea ta;
    TextField tfaddress, tfport, tftype;
    int port;
    Client client;
    Server server;
    boolean iamserver;
    static Face frm; 

    public Face() ...{
        clientBtn = new Button("客户端");
        serverBtn = new Button("服务器");
        ta = new TextArea("", 10, 50, TextArea.SCROLLBARS_BOTH);
        tfaddress = new TextField("192.168.1.104", 20);
        tfport = new TextField("2000");
        tftype = new TextField(50); 

        tftype.addKeyListener(new TFListener());
        ta.setEditable(false); 

        setLayout(new FlowLayout());
        add(tfaddress);
        add(tfport);
        add(clientBtn);
        add(serverBtn);
        add(ta);
        add(tftype);
        setSize(400, 300);
        setTitle("我的聊天室");
        this.setVisible(true); 

        clientBtn.addActionListener(new ActionListener() ...{
            public void actionPerformed(ActionEvent e) ...{ 

                port = Integer.parseInt(tfport.getText()); 

                client = new Client(tfaddress.getText(), port, frm); 

                client.start(); 

                tfaddress.setEnabled(false);
                tfport.setEnabled(false);
                serverBtn.setEnabled(false);
                clientBtn.setEnabled(false);
            }
        }); 

        serverBtn.addActionListener(new ActionListener() ...{
            public void actionPerformed(ActionEvent e) ...{ 

                port = Integer.parseInt(tfport.getText()); 

                server = new Server(port, frm); 

                server.start(); 

                iamserver = true;
                tfaddress.setText("成为服务器"); 

                tfaddress.setEnabled(false);
                tfport.setEnabled(false);
                serverBtn.setEnabled(false);
                clientBtn.setEnabled(false);
            }
        }); 

        addWindowListener(new WindowAdapter() ...{
            public void windowClosing(WindowEvent e) ...{
                System.exit(0);
            }
        }); 

    } 

    public static void main(String args[]) ...{
        frm = new Face();
    } 

    private class TFListener implements KeyListener ...{
        public void keyPressed(KeyEvent e) ...{ 

            if (e.getKeyCode() == KeyEvent.VK_ENTER) ...{ 

                ta.append(">" + tftype.getText() + " "); 

                if (iamserver)
                    server.dataout(tftype.getText());
                else
                    client.dataout(tftype.getText()); 

                tftype.setText("");
            }
        } 

        public void keyTyped(KeyEvent e) ...{
        } 

        public void keyReleased(KeyEvent e) ...{
        }
    }
}

转载请注明：本文作者：longlongago     博客地址：http://blog.youkuaiyun.com/longlongago2000

这个程序我限制了连接数，大家可以根据自己的需要进行修改。

欢迎和我交流：email liufeituo@163.com