java socket

package day1214;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class Client {
    private Socket socket=null;
    public Client(){
        try {
            socket=new Socket("192.168.0.103",8080);
            new ClientThread().start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    class ClientThread extends Thread{
        PrintWriter pw=null;
        public void run() {
            try {
                Scanner scanner=new Scanner(System.in);
                pw=new PrintWriter(socket.getOutputStream(),true);
                while (true){
                    String msg=scanner.next();
                    pw.println(msg);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            finally {
                try {
                    if(socket!=null){
                        socket.close();
                    }
                    if(pw!=null){
                        pw.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    public static void main(String[] args) {
        new Client();
    }
}

服务端

package day1214;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class Server {
    private ServerSocket server;

    private String msg="";

    private ArrayList<Socket> sockets;


    public Server(){
        try {
            int port=8080;
            server=new ServerSocket(port); //接受连接信号
            sockets=new ArrayList<Socket>();
            while(true){
                Socket socket=server.accept();
                sockets.add(socket);
                new MyThread(socket).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class MyThread extends Thread{
        private Socket socket;
        private BufferedReader br;
        private PrintWriter pw;
        public MyThread(Socket socket){
            this.socket=socket;
        }

        public void run() {
            try {
                br=new BufferedReader(new InputStreamReader(socket.getInputStream(),"utf-8"));
                System.out.println("欢迎["+socket.getInetAddress()+"]用户访问，一共进入了"+sockets.size()+"个用户");
                sendMsg();
                while((msg=br.readLine())!=null){
                    System.out.println("用户["+socket.getInetAddress()+"]说:"+msg);
                    //sendMsg();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            finally {
                try {
                    if(socket!=null){
                        sockets.remove(socket);
                        socket.close();
                    }
                    if(br!=null){
                        br.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        public void sendMsg(){
            try {
                //System.out.println(msg);
                for(Socket s:sockets){
                    pw=new PrintWriter(s.getOutputStream(),true);
                    //pw.println(msg);
                }
            }
            catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) {
        new Server();
    }
}