Following example shows how to check whether any port is being used as a server or not by creating a socket object.
import java.net.*;
import java.io.*;
public class Main {
public static void main(String[] args) {
Socket Skt;
String host = "localhost";
if (args.length > 0) {
host = args[0];
}
for (int i = 0; i < 1024; i++) {
try {
System.out.println("Looking for "+ i);
Skt = new Socket(host, i);
System.out.println("There is a server on port "
+ i + " of " + host);
}
catch (UnknownHostException e) {
System.out.println("Exception occured"+ e);
break;
}
catch (IOException e) {
}
}
}
}
Result:
The above code sample will produce the following result.
Looking for 0
Looking for 1
Looking for 2
Looking for 3
Looking for 4. . .