Multi-Threading

Hydrogen.java

public class Hydrogen implements Runnable{
	ReactionArea buff;
	
	public Hydrogen(ReactionArea buff){
		this.buff = buff;
	}
	
	public void run(){
		for(int i = 0; i < 20; i++){
			try{
				buff.increWHydrogen(i);
				Thread.sleep(100);
			} catch(InterruptedException e){
				e.printStackTrace();
				System.exit(1);
			}
		}
	}
}

Oxygen.java

public class Oxygen implements Runnable{
	ReactionArea buff;
	
	public Oxygen(ReactionArea buff){
		this.buff = buff;
	}
	
	public void run(){
		for(int i = 0; i < 20; i++){
			try{
				buff.increWOxygen(i);
				Thread.sleep(100);
			} catch(InterruptedException e){
				e.printStackTrace();
				System.exit(1);
			}
		}
	}
}

ReactionArea.java

public class ReactionArea {
	public int waitingHydrogen = 0;
	public int waitingOxygen = 0;
	
	public synchronized void increWHydrogen(int index){
		while(waitingHydrogen > 5){
			try {
				this.wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		waitingHydrogen += 20;
		System.out.println("The "+index+"th Hydrogen atom was added.");
		notifyAll();
	}
	
	public synchronized void increWOxygen(int index){
		while(waitingOxygen > 2){
			try {
				this.wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		waitingOxygen += 10;
		System.out.println("The "+index+"th Oxygen atom was added.");
		notifyAll();
	}
	
	public synchronized void react(int index){
		while(waitingHydrogen < 20 || waitingOxygen < 10){
			try {
				this.wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		waitingHydrogen -= 20;
		waitingOxygen -= 10;
		System.out.println("The "+index+"th water molecule was added.");
		notifyAll();
	}
}

Reactor.java

public class Reactor implements Runnable{
	ReactionArea buff;
	
	Reactor(ReactionArea buff){
		this.buff = buff;
	}
	
	@Override
	public void run() {
		for(int i = 0; i < 20; i++){
			try{
				buff.react(i);
				Thread.sleep(2000);
			} catch(InterruptedException e){
				e.printStackTrace();
				System.exit(1);
			}
		}
	}
	
}

Test.java

public class Test {

	public static void main(String[] args) {
		ReactionArea reactarea = new ReactionArea();
		Thread hydrogen = new Thread(new Hydrogen(reactarea));
		Thread oxygen = new Thread(new Oxygen(reactarea));
		Thread reactor = new Thread(new Reactor(reactarea));
		hydrogen.run();
		oxygen.run();
		reactor.run();
	}

}