JAVA中Socket服务器/客户端的通信

<span style="font-size:18px;">package com.cr.bean;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.Scanner;

public class client001 {
@SuppressWarnings("resource")
public static void main(String []args){
Scanner scanner = new Scanner(System.in);
Socket mysocket = null;
DataInputStream in = null;
DataOutputStream out = null;
try {
mysocket = new Socket();
System.out.println("请输入服务器IP：");
String IP = scanner.nextLine();
System.out.println("请输入端口号：");
int port = scanner.nextInt();
if(mysocket.isConnected()){}
else{
//连接服务器，使用多线程技术
InetAddress address = InetAddress.getByName(IP);
InetSocketAddress socketAddress = new InetSocketAddress(address,port);
mysocket.connect(socketAddress);
System.out.println(socketAddress.toString());
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
}
} catch (Exception e) {
System.out.print("服务器连接已断开"+e);
}
while(true){
String str = null;
try {
str = scanner.nextLine();
out.writeUTF(str);
} catch (Exception e) {
System.exit(0);
}
}
}
}</span><span style="color:#ff0000;">
</span>

<span style="font-size:18px;">package com.cr.bean;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;

public class serve001 {
@SuppressWarnings("resource")
public static void main(String[] args){
ServerSocket server = null;
Socket you = null;

while(true){
try {
server = new ServerSocket(7777);
} catch (IOException e) {
System.out.println("正在监听……");
}
try {
you = server.accept();
System.out.println("客户的地址："+you.getInetAddress());
} catch (IOException e) {
System.out.println("正在等待客户");
}
if(you!=null){
new ServerThread(you).start();//为每个客户启动一个专门的线程
}
}
}
}

class ServerThread extends Thread{
Socket socket;
DataOutputStream out = null;
DataInputStream in = null;
String s = null;
ServerThread(Socket t){
socket = t;
try {
out = new DataOutputStream(socket.getOutputStream());
in = new DataInputStream(socket.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void run() {

try {
while(true){
String str = in.readUTF();
System.out.println("客户端发送给服务器说："+str);
}
} catch (Exception e) {
System.out.println("客户离开");
}
}
}</span><span style="font-size:32px;font-weight: bold;">
</span>