Dining Philosopher - Only 4

import java.util.Random;
import java.util.concurrent.Semaphore;

class Demonstration {
  public static void main(String[] args) throws Exception {
    DiningPhilosophers diningPhilosophers = new DiningPhilosophers();
    Thread[] threads = new Thread[5];
    for (int i = 0; i < 5; i++) {
      final int index = i;
      threads[i] =
          new Thread(
              () -> {
                try {
                  diningPhilosophers.lifeCycleOfPhilosopher(index);
                } catch (InterruptedException e) {
                  System.out.println("Philosopher is interrupted");
                }
              });
    }
    for (Thread thread : threads) {
      thread.start();
    }
    for (Thread thread : threads) {
      thread.join();
    }
  }
}

class DiningPhilosophers {
  private Semaphore[] forks = new Semaphore[5];
  private Semaphore currentlyEatingPhilosophers = new Semaphore(4);
  private static Random random = new Random(System.currentTimeMillis());

  public DiningPhilosophers() {
    for (int i = 0; i < 5; i++) {
      forks[i] = new Semaphore(1);
    }
  }

  public void lifeCycleOfPhilosopher(int id) throws InterruptedException {
    while (true) {
      contemplate(id);
      eat(id);
    }
  }

  private void contemplate(int id) throws InterruptedException {
    System.out.println("Philosopher " + id + " is contemplating.");
    Thread.sleep(random.nextInt(100));
  }

  private void eat(int id) throws InterruptedException {
    currentlyEatingPhilosophers.acquire();
    forks[id].acquire();
    forks[(id + 1) % 5].acquire();
    eatNoodle(id);
    forks[id].release();
    forks[(id + 1) % 5].release();
    currentlyEatingPhilosophers.release();
  }

  private void eatNoodle(int id) throws InterruptedException {
    System.out.println("Philosopher " + id + " is eating noodle");
    Thread.sleep(random.nextInt(100));
    System.out.println("Philosopher " + id + " finished eating noodle");
  }
}