Exchanger Class

[allaudin]

Hy everybody, please have a look why this code doesn't show any output ... thanks in advance

/* ---- Exchanger Class Demo ---*/

import java.util.concurrent.Exchanger;

class MakeString implements Runnable{
		Exchanger<String> exg;
		String str;
		
		public MakeString(Exchanger<String> exg){
			
			this.exg = exg;
			str = new String();
			new Thread(this).start();
		}
		
		public void run(){
			char c = 'A';
			
			for(int i = 0; i < 3; i++){
				
				for(int j = 0; i < 5; j++) str += c++;
					try{
						str = exg.exchange(str);  /* exchange with empty string */
						}catch(InterruptedException IE){
							System.err.println("Thread Interrupted");
					}
			
			}
		}
}

class UseString implements Runnable{
	
	Exchanger<String> exg;
	String str;
	
	public UseString(Exchanger<String> exg){
		this.exg = exg;
		new Thread(this).start();
	}
	
	public void run(){
		
		try{
				for(int i = 0; i < 3; i++){
						str = exg.exchange(new String());
						System.out.println("GOT: " + str);
				}
		}catch(InterruptedException ie){
			System.err.println("Thread Interrupted");
		}
	}

}
public class ExchangerApp{

	public static void main(String[] args){
			Exchanger<String> exg = new Exchanger<>();
			new UseString(exg);
			new MakeString(exg);
	}
}

[Norm]

why this code doesn't show any output

That is usually because no print statements are executed. Often that is because of logic problems.

Try debugging the by adding some println() statements to print out the values of variables as the code executes so you can see what the computer sees when it executes and know why it is doing what it is doing when the code executes.

[allaudin]

k. thanks ...