Wednesday, May 20, 2015

a Java Class which scans ports in an IP

I had to run port scanner software for security check reason, before deliver the product. I tried to get one utilillity from internet. but, the Websites were blocked in my company to download. so, I just made a Java Class which can do the port scanning. it takes around 20 min to run throught all the ports. If I increase Thread size and shorten the timeout, it will take less then 5 min.

Fornow, I have a little problem. When I let it run quickly, Firewall or security software get activated and deny to response if the port is opened. So, I had to let it run slowly to find all the opened port.

package com.devtrigger;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

class PortScanner {

    public static void main(final String... args) throws InterruptedException, ExecutionException {
        final ExecutorService es = Executors.newFixedThreadPool(15);

        final String ip = "";

        final int timeout = 200;
        final List<Future<ScanResult>> futures = new ArrayList<>();
        for (int port = 1; port <= 65535; port++) {
            futures.add(portIsOpen(es, ip, port, timeout));
        es.awaitTermination(200L, TimeUnit.MILLISECONDS);
        int openPorts = 0;
        for (final Future<ScanResult> f : futures) {
            if (f.get().isOpen()) {
        System.out.println("There are " + openPorts + " open ports on host " + ip + " (probed with a timeout of "
                + timeout + "ms)");

    public static Future<ScanResult> portIsOpen(final ExecutorService es, final String ip, final int port,
            final int timeout) {
        return es.submit(new Callable<ScanResult>() {
            public ScanResult call() {
                try {
                    Socket socket = new Socket();
                    socket.connect(new InetSocketAddress(ip, port), timeout);
                    return new ScanResult(port, true);
                } catch (Exception ex) {
                    return new ScanResult(port, false);

    public static class ScanResult {
        private int port;

        private boolean isOpen;

        public ScanResult(int port, boolean isOpen) {
            this.port = port;
            this.isOpen = isOpen;

        public int getPort() {
            return port;

        public void setPort(int port) {
            this.port = port;

        public boolean isOpen() {
            return isOpen;

        public void setOpen(boolean isOpen) {
            this.isOpen = isOpen;


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