java在线聊天项目0.8版 实现把服务端接收到的信息返回给每一个客户端窗口中显示功能

迭代器的方式会产生锁定

服务器端增加发送给每个客户端已收到信息的功能

所以当获取到一个socket，并打开它的线程进行循环接收客户端发来信息时，我们把这个内部类的线程Client保存到集合List<Client>中

然后在读取到客户端信息后，把这个信息发送给所有端口

通过循环

for(int i=0;i<clients.size();i++){

　　Client c=clients.get(i);

　　c.send(str);

}

发送给每一个已经成功连接到服务端的客户端

服务端详细的代码修改如下：

package com.swift;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ChatServer {

    boolean started = false;
    ServerSocket ss = null;
    Socket s = null;
    List<Client> clients=new ArrayList<Client>();  

    public static void main(String[] args) {
        new ChatServer().fun();
    }

    private void fun() {
        try {
            ss = new ServerSocket(8888);
            started = true;
        } catch (BindException e) {
            System.out.println("端口使用中......");
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        try {
            while (started) {
                s = ss.accept();
                System.out.println("a client connected success");
                Client c = new Client(s);
                new Thread(c).start();
                clients.add(c);
            }
        } catch (EOFException e) {
            System.out.println("client has closed.");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                ss.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    class Client implements Runnable {

        private Socket s;
        private DataInputStream dis;
        private DataOutputStream dos;
        private boolean connected = false;

        public Client(Socket s) {
            this.s = s;
            try {
                this.dis = new DataInputStream(s.getInputStream());
                this.dos = new DataOutputStream(s.getOutputStream());
                connected = true;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        private void send(String str) {
            try {
                dos.writeUTF(str);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            };
        }
        @Override
        public void run() {
            try {//注意:要包括while循环，如果try在while循环里，则出现socket closed异常
                while (connected) {
                    String str = dis.readUTF();
                    System.out.println(str);
                    for(int i=0;i<clients.size();i++) {
                        Client c=clients.get(i);
                        c.send(str);
                    }

//                     for(Iterator<Client> it=clients.iterator();it.hasNext();) {
//                         Client c=it.next();//方法二，不可取，有同步锁
//                         c.send(str);
//                     }

//                    Iterator<Client> it=clients.iterator();
//                    while(it.hasNext()) {
//                        Client c=it.next();//方法三，不可取，有同步锁,修改需要加锁（此时没修改）
//                        c.send(str);
//                    }

                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (dis != null) {
                    try {
                        dis.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if (s != null) {
                    try {
                        s.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if(dos!=null) {
                    try {
                        dos.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

        }

    }
}