How do I run the Linux command, “netstat” from a Java program?

Question

I have a client-server project written in Java in which they connect through sockets. I cannot figure out how to run “netstat” from the server side of my Java code.

Answer 1

Unfortunately there is no netstat equivalent available directly in java.

You could use the process API to spawn a new process and check the output.

I will use an example from the following q/a: https://stackoverflow.com/a/5711150/1688441

I have changed it to call netstat. After spawning the process you will also have to read the output and parse it.

Runtime rt = Runtime.getRuntime();
String[] commands = {"netstat", ""};
Process proc = rt.exec(commands);

BufferedReader stdInput = new BufferedReader(new 
     InputStreamReader(proc.getInputStream()));

BufferedReader stdError = new BufferedReader(new 
     InputStreamReader(proc.getErrorStream()));

// Read the output from the command
System.out.println("Here is the standard output of the command:\n");
String s = null;
while ((s = stdInput.readLine()) != null) {
    System.out.println(s);
}

// Read any errors from the attempted command
System.out.println("Here is the standard error of the command (if any):\n");
while ((s = stdError.readLine()) != null) {
    System.out.println(s);
}

Source: https://stackoverflow.com/a/5711150/1688441