如何在Java中查找由IP地址建立的TCP连接数？

Question

I'm trying to implement Hop Count Filtering Algorithm. In order to update HCF table to prevent IP Spoofing, I need to update a counter when an IP address has TCP connections in established state in Java.

Answer 1

Excecuting the netstat -at | grep ESTA netstat -at | grep ESTA you will get all TCP connections established in you machine. To run this command in Java you can use Runtime.getRuntime().exec() as follow

public class Test {
    public static void main(String args[]) {
        String s;
        Process p;
        try {
            p = Runtime.getRuntime().exec("netstat -at | grep ESTA");
            BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));

            while ((s = br.readLine()) != null){

                // Update here counters if an IP have established a new TCP connection
                System.out.println("line: " + s);
            }

            p.waitFor();
            p.destroy();
        } catch (Exception e) {}
    }
}

Hope it helps.