socket和端口的问题？？？

[yrh2847189]

import java.net.*;
import java.io.*;
public class PacketReceiveDemo
{
public static void main(String[] args)
{
try
{
System.out.println("Binding to local port 2000");
DatagramSocket socket = new DatagramSocket(2000);
System.out.println("Bound to local port"+socket.getLocalPort());
DatagramPacket packet= new DatagramPacket(new byte[256],256);
socket.receive(packet);
System.out.println("Packet received!");

InetAddress remote_addr= packet.getAddress();
System.out.println("send by:"+remote_addr.getHostAddress());
System.out.println("Send from:"+packet.getPort());

ByteArrayInputStream bin= new ByteArrayInputStream(packet.getData());
for (int i=0;i<packet.getLength();i++)
{
int data = bin.read();
if(data==-1)
break;
else
System.out.print((char)data);
}
socket.close();
}
catch(IOException ioe){
System.err.println("Err-"+ioe);
}
}
}
接受方

[yrh2847189]

import java.net.*;
import java.io.*;
public class PacketSendDemo
{
public static void main(String[] args)
{
int argc = args.length;
if (argc !=1)
{
System.out.println("Syntax:");
System.out.println("java PacketSendDemo hostname");
return;
}
String hostname = args[0];
try
{
System.out.println("Binding to a local port");
DatagramSocket socket = new DatagramSocket();
System.out.println("Bound to lical port"+socket.getLocalPort());
ByteArrayOutputStream bout = new ByteArrayOutputStream();
PrintStream pout = new PrintStream(bout);
pout.print("Greeting");

byte[] barray =bout.toByteArray();

DatagramPacket packet = new DatagramPacket( barray, barray.length);
System.out.println("Looking up hostname"+hostname);

InetAddress remote_addr = InetAddress.getByName(hostname);
System.out.println("Hostname resolved as"+remote_addr.getHostAddress());
packet.setAddress (remote_addr);
packet.setPort (2000);
System.out.println("Packet sent!");
}
catch (UnknownHostException uhe){
System.out.println("Can't find host"+hostname);
}
catch (IOException ioe)
{
System.err.println("Eror-"+ioe);
}
}
}
发送方
但是接受方收不到信息啊

[hanwei39]

看看你发送方的OutputStream关闭了没有。