先看代码:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;
public class Sender {
private static DatagramSocket send; //套接字
private static byte[] buff; //缓冲区
private static DatagramPacket packetReceived; //接收的包
private static InetAddress inetAddress;
public Sender() throws Exception {
buff = new byte[1024];
packetReceived = new DatagramPacket(buff,buff.length);
inetAddress = InetAddress.getByName("localhost");
send = new DatagramSocket(5000);
}
private static String send() throws IOException {
Scanner scan = new Scanner(System.in);
//要发送的信息
String str = scan.next();
byte[] buff = str.getBytes();
//数据报文
DatagramPacket datagramPacket = new DatagramPacket(buff,buff.length,inetAddress,4000);
//发送
send.send(datagramPacket);
return str;
}
private static String receive() throws IOException {
send.receive(packetReceived);
String str = new String(packetReceived.getData(),0,packetReceived.getLength());
return str;
}
public static void main(String[] args) throws Exception {
Sender sender = new Sender();
new Thread(){
@Override
public void run() {
while (true){
String msg = null;
try {
msg = send();
} catch (IOException e) {
e.printStackTrace();
}
if(msg.equals("bye")){
send.close();
System.out.println("本次聊天结束");
System.exit(0);
}
}
}
}.start(); //创建线程,调用start方法启动线程
new Thread(){
@Override
public void run() {
while (true) {
String msg = null;
try {
msg = receive();
} catch (IOException e) {
e.printStackTrace();
}
System.out.printf("%s:%s\n",packetReceived.getAddress().getHostAddress(),msg);
if(msg.equals("bye")){
send.close();
System.out.println("本次聊天结束");
System.exit(0);
}
}
}
}.start();
}
}
这实现了一个简单的聊天聊天工具,当然仅平这一个类还是不够的,如果是打算在自己电脑上实现两天,则需要在写一个类,代码跟这个一模一样,改改类名就好,然后运行两个类,就可以互发信息了.如果想在两台电脑之间通信,就需要在另一台电脑上也写上代码,然后将inetAddress = InetAddress.getByName("localhost");里面的localhost改成对方的ip地址,注意两台电脑须在同意局域网下,方可通信