school/java/week10/assignment/Main.java

package edu.grcc;

public class Main {
	public static void main(String[] args) {
	// Create tasks
	Runnable printA = new PrintChar('a', 100);
	Runnable printB = new PrintChar('b', 100);
	Runnable print100 = new PrintNum(100);

	//Create threads
	Thread thread1 = new Thread(printA);
	Thread thread2 = new Thread(printB);
	Thread thread3 = new Thread(print100);

	// Start threads
	thread1.start();
	thread2.start();
	thread3.start();
    }
}

// The task for printing a specified character in specified times

class PrintChar implements Runnable {
	private char charToPrint; // the char to print
	private int times; // Times to repeat

	/** Construct a task with specified character and number of
	 *  times to print the char
	 */
	public PrintChar(char c, int t) {
		charToPrint = c;
		times = t;
	}

	@Override /** Override the run() method to tell the system
				* what the task to perform
				*/
	public void run() {
		for (int i = 0; i < times; i++) {
			System.out.print(charToPrint);
			Thread.yield();

			try {
			    if (i >= 50) Thread.sleep(100);
			}
			catch (InterruptedException ex) {
			}
		}
	}
}

// The task class for printing number from 1 to n for a given n
class PrintNum implements Runnable {
	private int lastNum;

	// Construct a task for printing 1, 2, ... i
	public PrintNum(int n) {
		lastNum = n;
	}

	@Override // Tell the thread how to run
	public void run() {
	    Thread thread4 = new Thread(
					new PrintChar('c', 40));
		thread4.start();
	    
		try {
		     for (int i = 1; i <= lastNum; i++) {
			 System.out.print(" " + i);
			 if (i == 50) thread4.join();
		     }
		}
		catch (InterruptedException ex) {
		}
	}
}