❶ 關於java UDP方面的一些問題
我把我的代碼借鑒給你..不知道能不能夠幫助你..!!!自己原創的
UDPServer.java:
import java.net.*;
import java.util.*;
public class UDPServer extends Thread {
private static final int PORT=10000 ;
private static final int DATA_LEN=2046 ;
private byte []buff =new byte[DATA_LEN];
UDPClient.java:
import java.net.*;
import java.util.*;
public class UDPClient extends Thread {
private static final int PORT=10000 ;
private static final int DATA_LEN=2046 ;
private byte []buff =new byte[DATA_LEN];
private DatagramSocket socket ;
private DatagramPacket inpacket =new DatagramPacket(buff,buff.length);
private DatagramPacket outpacket ;
public void run() {
int i =0;
try{
socket=new DatagramSocket();
outpacket =new DatagramPacket(new byte[0] ,0,
InetAddress.getByName("127.0.0.1"),PORT);
Scanner sc =new Scanner(System.in);
while(sc.hasNextLine()){
byte [] buff1 =sc.nextLine().getBytes();
outpacket.setData(buff1);
socket.send(outpacket);
socket.receive(inpacket);
System.out.println(new String(buff,0,inpacket.getLength()));
}
}catch(Exception e){
e.printStackTrace();
}
}
public static void main(String []args){
new UDPClient().start();
}
/*public UDPServer (DatagramSocket socket ,DatagramPacket inpacket,
DatagramPacket outpacket) {
this.socket = socket ;
this.inpacket = inpacket ;
this.outpacket = outpacket ;
}*/
};
MulticastSocketTest.java:
import java.awt.*;
import java.net.*;
import java.io.*;
import java.util.*;
//讓該類實現Runnable介面，該類的實例可作為線程的target
public class MulticastSocketTest implements Runnable
{
//使用常量作為本程序的多點廣播IP地址
private static final String BROADCAST_IP
= "230.0.0.1";
//使用常量作為本程序的多點廣播目的的埠
public static final int BROADCAST_PORT = 30000;
//定義每個數據報的最大大小為4K
private static final int DATA_LEN = 4096;
//定義本程序的MulticastSocket實例
private MulticastSocket socket = null;
private InetAddress broadcastAddress = null;
private Scanner scan = null;
//定義接收網路數據的位元組數組
byte[] inBuff = new byte[DATA_LEN];
//以指定位元組數組創建准備接受數據的DatagramPacket對象
private DatagramPacket inPacket =
new DatagramPacket(inBuff , inBuff.length);
//定義一個用於發送的DatagramPacket對象
private DatagramPacket outPacket = null;
public void init()throws IOException
{
try
{
//創建用於發送、接收數據的MulticastSocket對象
//因為該MulticastSocket對象需要接收，所以有指定埠
socket = new MulticastSocket(BROADCAST_PORT);
broadcastAddress = InetAddress.getByName(BROADCAST_IP);
//將該socket加入指定的多點廣播地址
socket.joinGroup(broadcastAddress);
//設置本MulticastSocket發送的數據報被回送到自身
socket.setLoopbackMode(false);
//初始化發送用的DatagramSocket，它包含一個長度為0的位元組數組
outPacket = new DatagramPacket(new byte[0] , 0 ,
broadcastAddress , BROADCAST_PORT);
//啟動以本實例的run()方法作為線程體的線程
new Thread(this).start();
//創建鍵盤輸入流
scan = new Scanner(System.in);
//不斷讀取鍵盤輸入
while(scan.hasNextLine())
{
//將鍵盤輸入的一行字元串轉換位元組數組
byte[] buff = scan.nextLine().getBytes();
//設置發送用的DatagramPacket里的位元組數據
outPacket.setData(buff);
//發送數據報
socket.send(outPacket);
}
}
finally
{
socket.close();
}
}
public void run()
{
try
{
while(true)
{
//讀取Socket中的數據，讀到的數據放在inPacket所封裝的位元組數組里。
socket.receive(inPacket);
//列印輸出從socket中讀取的內容
System.out.println("聊天信息：" + new String(inBuff , 0 ,
inPacket.getLength()));
}
}
//捕捉異常
catch (IOException ex)
{
ex.printStackTrace();
try
{
if (socket != null)
{
//讓該Socket離開該多點IP廣播地址
socket.leaveGroup(broadcastAddress);
//關閉該Socket對象
socket.close();
}
System.exit(1);
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
public static void main(String[] args)
throws IOException
{
new MulticastSocketTest().init();
}
}
private DatagramSocket socket ;
private DatagramPacket inpacket ;
private DatagramPacket outpacket ;
public void run() {
int i =0;
try{
socket=new DatagramSocket(PORT);
while(true){
inpacket=new DatagramPacket(buff,buff.length);
socket.receive(inpacket) ;
System.out.println(new String(buff,0,inpacket.getLength()));
byte [] sedData =new String("數據信息："+i).getBytes();
outpacket =new DatagramPacket(sedData,sedData.length,inpacket.getSocketAddress());
socket.send(outpacket);
i++ ;
}
}catch(Exception e){
e.printStackTrace();
}
}
public static void main(String []args){
new UDPServer().start();
}
/*public UDPServer (DatagramSocket socket ,DatagramPacket inpacket,
DatagramPacket outpacket) {
this.socket = socket ;
this.inpacket = inpacket ;
this.outpacket = outpacket ;
}*/
};