I am developing eclipse plugin for our organization . We are opening multiple servers[minimum 10 servers] on a user machine using this plugin via eclipse . For starting servers we want port numbers which has been not already binded . For that , I am using serversocket to check this . I think it's a costly operation to open a serversocket object . Internally serversocket will check the port is already binded or not It takes minimum 50 milliseconds . Here is my code to return a free port . Is there any way to find already occupied ports without using OS Commands and opening ServerSocket ?
/**
*Tries 100 times
* @param port
* modes
* 1.increment - 1
* This mode increment the port with your start value . But it's costly operation because each time we open a socket and check the port is free .
* 2.decrement - 2
* Invert of increment.
* 3.random - 3
* Randomly choose based on your starting point
* @return
*/
public static String getDefaultPort(int port , int mode){
int retry = 100;
int random = 3;
int increment = 1;
int decrement = 2;
while(true){
//this is for preventing stack overflow error.
if(retry < 1){ //retries 100 times .
break;
}
if(mode==increment){
port++;
}else if(mode == decrement){
port--;
}else if(mode == random){
port = (int) (port+Math.floor((Math.random()*1000)));
}
if(validate(port+"")){
long end = System.currentTimeMillis();
return port+"";
}
}
return "";
}
public boolean validate(String input) {
boolean status = true;
try {
int port = Integer.parseInt(input);
ServerSocket ss = new ServerSocket(port);
ss.close();
}
catch (Exception e) {
status = false;
}
return status;
}
