使用socket实现聊天功能

public class Service {  //服务器

    public static void main(String[] args) {
      ServerSocket serverSocket=null;
      Socket socket=null;
      //既然是 双方的通信   输入和输出流 必须有
      OutputStream os=null;
      InputStream  is=null;
      BufferedReader  br=null;
      byte [] buf=new byte[1024];
      int   say;  
      String  word=null;
          try {
              serverSocket=new ServerSocket(8800);
              while(true){ //始终保持 畅通
            socket=serverSocket.accept();
            //实现多个窗口聊天
            ThreadSocket socket2=new ThreadSocket(socket);
            socket2.start();
            /*//打开所有的输入输出流
            is=socket.getInputStream();
            os=socket.getOutputStream();
            //接收客户端的信息
            say=is.read(buf);
            if (say!=0) {
                word =new String(buf, 0, say);
            }
            System.out.println(word);
            //给客户的回应
            System.out.println("====请您输入需要回复的信息====");
            br=new BufferedReader(new InputStreamReader(System.in));
            os.write(br.readLine().getBytes());  //保证都是 最新的回复
*/              }
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try {
                br.close();
                os.close();
                is.close();
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            
        }
          
      }
    
}

public class ThreadSocket extends Thread {

    //相当于每一个单独的窗口
    Socket socket = null;

    public ThreadSocket(Socket socket) {
        this.socket = socket;
    }

    @Override
    public void run() {
        String words = null;
        int say;
        InputStream is = null;
        OutputStream os = null;
        byte[] rece = new byte[1000];
        try {
                     //打开需要的 输入 输出流
            is = socket.getInputStream();
            os = socket.getOutputStream();
            say = is.read(rece);// 接受客户端消息
            if (say != 0)
                words = new String(rece, 0, say);
            System.out.println(words);
            BufferedReader bufferreader = new BufferedReader(
                    new InputStreamReader(System.in));
            os.write(("服务器====" + bufferreader.readLine()).getBytes());// 返回给客户端的响应
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
                os.close();
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

public class Client {  //客户端
    
    public static void main(String[] args) {
          Socket socket=null;
          //既然是 双方的通信   输入和输出流 必须有
          OutputStream os=null;
          InputStream  is=null;
          InputStreamReader reader=null;
          byte [] buf=new byte[1024];
          int   say;  
          String  word=null;
          String  server=null;
          String address=null;  
          InetAddress host=null;
            try {
                System.out.println("亲爱的用户：请您输入服务器的ip地址：");
                reader=new InputStreamReader(System.in);
                word=new BufferedReader(reader).readLine();  //获取用户的输入IP
                 if (word!="") {
                     address=word;  //
                }
                //开始和服务器 交流
                 System.out.println("=======说出您想提问的问题=======");
                 reader=new InputStreamReader(System.in);
                 while(true){
                     word=new BufferedReader(reader).readLine();// 获取用户想说的话
                     server=word;
                     //获取本机的IP
                     host = InetAddress.getLocalHost();
                     word=host+"=====:"+server;  //需要发送给 服务器的信息
                     
                     socket=new Socket(InetAddress.getByName(address), 8800);
                       //打开所有的输入输出流
                        is=socket.getInputStream();
                        os=socket.getOutputStream();
                         //设置通信的编码格式
                        os.write(word.getBytes("gbk")); //发送数据
                      //接收
                        say=is.read(buf);
                    System.out.println("服务器说："+new String(buf, 0, say));    
                 }
            } catch (IOException e) {
                e.printStackTrace();
            }finally{
                try {
                    os.close();
                    is.close();
                    socket.close();
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    }

}