UDP发包接包，接收端终止问题？Why？ - 黑马程序员技术交流社区

import java.net.*;
import java.io.*;
import java.util.Date;
public class UdpSocketTest{
public static boolean FLAG = true ;
public static void main(String[] args){
}
}
class SerSocket{
public static void main(String[] args) throws Exception{
DatagramSocket ds = new DatagramSocket(40009);
while(UdpSocketTest.FLAG)
{
byte[] buf = new byte[1024];
DatagramPacket dp = new DatagramPacket(buf,buf.length);
ds.receive(dp);
InetAddress ia = dp.getAddress();
String ip = ia.getHostAddress();
System.out.println(ip+"..... connected");
String content = new String(dp.getData(),0,dp.getLength());
content = content.toUpperCase();
System.out.println("content=="+content);
Thread.sleep(5000); //先暂停5秒，等if over先执行，置FLAG为false
Date d = new Date();
System.out.println(d.toString()+"Ser执行UdpSocketTest.FLAG==::"+UdpSocketTest.FLAG);
}
ds.close();
}
}
class CliSocket{
public static void main(String[] args) throws Exception{
DatagramSocket ds = new DatagramSocket();
InetAddress ia = InetAddress.getByName("127.0.0.1");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = null;
while((line=br.readLine())!=null){
byte[] buf = line.getBytes();
DatagramPacket dp = new DatagramPacket(buf,buf.length,ia,40009);
ds.send(dp);
if("over".equals(line))
{
UdpSocketTest.FLAG = false;
Date d = new Date();
System.out.println(d.toString()+"Cli执行UdpSocketTest.FLAG==::"+UdpSocketTest.FLAG);
break ;
}
}
ds.close();
br.close();
}
}

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import java.net.*;
import java.io.*;
import java.util.Date;
public class UdpSocketTest2{
//public static boolean FLAG = true ;
private static final UdpSocketTest2 ut = new UdpSocketTest2(); //郁闷，换成单例类，还是一样存在问题。
private boolean flag = true ;
private UdpSocketTest2(){
}
public static UdpSocketTest2 getInstance(){
return ut ;
}
public void setFlag(boolean flag){
this.flag = flag;
}
public boolean getFlag(){
return flag ;
}
public static void main(String[] args){
}
}
class SerSocket{
public static void main(String[] args) throws Exception{
DatagramSocket ds = new DatagramSocket(40009);
UdpSocketTest2 ut = UdpSocketTest2.getInstance();
while(ut.getFlag())
{
byte[] buf = new byte[1024];
DatagramPacket dp = new DatagramPacket(buf,buf.length);
ds.receive(dp);
InetAddress ia = dp.getAddress();
String ip = ia.getHostAddress();
System.out.println(ip+"..... connected");
String content = new String(dp.getData(),0,dp.getLength());
content = content.toUpperCase();
System.out.println("content=="+content);
Thread.sleep(5000); //先暂停5秒，等if over先执行，置FLAG为false
Date d = new Date();
System.out.println(d.toString()+"Ser 执行ut.getFlag()==::"+ut.getFlag());
}
ds.close();
}
}
class CliSocket{
public static void main(String[] args) throws Exception{
UdpSocketTest2 ut = UdpSocketTest2.getInstance();
DatagramSocket ds = new DatagramSocket();
InetAddress ia = InetAddress.getByName("127.0.0.1");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = null;
while((line=br.readLine())!=null){
byte[] buf = line.getBytes();
DatagramPacket dp = new DatagramPacket(buf,buf.length,ia,40009);
ds.send(dp);
if("over".equals(line))
{
ut.setFlag(false);
Date d = new Date();
System.out.println(d.toString()+"Cli 执行ut.getFlag()==::"+ut.getFlag());
break ;
}
}
ds.close();
br.close();
}
}

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