Alright, so I’m trying to make a upc client/server and I keep running into this problem no matter where I bind the socket. Maybe someone can tell me what I’m doing wrong?
Note: this is as small as I could make these test cases.
Server:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class TestServer {
static DatagramSocket socket;
public static void main(String[] args){
int MAX_PLAYERS = 2;
int playerNum = 0;
boolean listening = true;
while(listening){
byte[] buf = new byte[255];
DatagramPacket packet = new DatagramPacket(buf, buf.length);
System.out.println("Waiting for packet from player: " + playerNum + "\n");
try {
socket = new DatagramSocket(4444);
} catch (SocketException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
socket.receive(packet);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Waiting to connect with player: " + playerNum + "\n");
new ClientThread(packet,playerNum).start();
//stops here.
System.out.println("Connected with player: " + playerNum + " Now incrementing" + "\n");
playerNum++;
System.out.println("Incremented to: " + playerNum+ "\n");
}
//serverSocket.close();
System.exit(0);
}
}
Client thread (server)
import java.net.*;
import java.nio.ByteBuffer;
public class ClientThread extends Thread implements Runnable{
int playerNum;;
DatagramSocket socket;
InetAddress address;
int port;
public ClientThread(DatagramPacket packet, int playerNum){
super("ClientThread");
address = packet.getAddress();
port = packet.getPort();
this.playerNum = playerNum;
}
public void run(){
try{
System.out.println("Thread" + playerNum + ": " + "Accepted. Now creating I/O.\n");
while(true){
socket = new DatagramSocket(port);
byte[] buf = new byte[255];
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
ByteBuffer recieveBuf = ByteBuffer.wrap(packet.getData());
recieveBuf.flip();
System.out.println("Thread" + playerNum + ": " + recieveBuf.toString());
ByteBuffer sendBuf = ByteBuffer.allocate(255);
sendBuf.asCharBuffer();
String s = "Thread" + playerNum + ": " + "sent data";
sendBuf.put(s.getBytes("ASCII"));
DatagramPacket packet2 = new DatagramPacket(sendBuf.array(), sendBuf.array().length, address, port);
socket.send(packet2);
socket.close();
this.sleep(15);
}
}
catch(Exception e){
e.printStackTrace();
System.exit(1);
}
}
}
Client
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.ByteBuffer;
public class TestClient {
static ClientThread ct;
static int playerNum = 0;
public static void main(String[] args){
//String ip = JOptionPane.showInputDialog("Input server IP.");
ct = new ClientThread();
ct.start();
ct.setPriority(Thread.MAX_PRIORITY);
playerNum = ct.playerNum;
}
}
class ClientThread extends Thread implements Runnable{
DatagramSocket socket;
DatagramPacket packet;
int playerNum;
boolean loop = true;
int port;
byte [] addr;
InetAddress address;
public ClientThread(){
super("ClientThread");
try{
playerNum = 0;
System.out.println(playerNum);
port = 4445;
addr = new byte[] {(byte) 76,(byte) 121,(byte) 76,(byte) 188};
address = InetAddress.getByAddress(addr);
byte[] buf = new byte[10];
socket = new DatagramSocket(4444);
DatagramPacket packet = new DatagramPacket(buf, 10, address, 4444);
System.out.println("send" + address.toString());
socket.send(packet);
}
catch(Exception e){
e.printStackTrace();
}
}
public void run(){
try{
while(loop){
try{
socket = new DatagramSocket(4444);
System.out.println("start");
//byte[] sendBuf = new byte[256];
ByteBuffer sendBuf = ByteBuffer.allocate(255);
sendBuf.asCharBuffer();
String s = "Thread" + playerNum + ": " + "sent data";
sendBuf.put(s.getBytes("ASCII"));
DatagramPacket packet = new DatagramPacket(sendBuf.array(), sendBuf.array().length, address, port);
System.out.println("send" + address.toString());
socket.send(packet);
System.out.println("sent");
byte[] buf = new byte[255];
packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
ByteBuffer receiveBuf = ByteBuffer.allocate(512);
receiveBuf.put(packet.getData());
receiveBuf.flip();
System.out.println("Thread" + playerNum + ": " + receiveBuf.toString());
this.sleep(15);
}
catch(Exception e){
e.printStackTrace();
//socket.close();
}
}
}
catch(Exception e){
e.printStackTrace();
}
}
}
Server output:
Waiting for packet from player: 0
Waiting to connect with player: 0
Connected with player: 0 Now incrementing
Incremented to: 1
Waiting for packet from player: 1
Thread0: Accepted. Now creating I/O.
java.net.BindException: Address already in use: Cannot bind
at java.net.PlainDatagramSocketImpl.bind0(Native Method)
at java.net.PlainDatagramSocketImpl.bind(Unknown Source)
at java.net.DatagramSocket.bind(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at ClientThread.run(ClientThread.java:24)
Client Exception:
java.net.BindException: Address already in use / at java.net.PlainDatagramSocketImpl.bind0(Native Method) / at java.net.AbstractPlainDatagramSocketImpl.bind(AbstractPlainDatagramSocketImpl.java:85) / at java.net.DatagramSocket.bind(DatagramSocket.java:373) / at java.net.DatagramSocket.<init>(DatagramSocket.java:229) / at java.net.DatagramSocket.<init>(DatagramSocket.java:282)
at java.net.DatagramSocket.<init>(DatagramSocket.java:254) / at ClientThread.run(TestClient.java:60)
So can anyone see what I’m doing wrong?