print pattern as "1 a 2 b 3 c 4 d 5 e" from following program

[mukeshgulia]

class thread1 implements Runnable
{	public void run()
	{	try
		{	for(int i=1;i<=5;i++)
			{	System.out.println(i);
			}
		}
		catch(Exception e)
		{	System.out.println(e);
		}
	}
}

class thread2 implements Runnable
{	char [] alphabets={'a','b','c','d','e'};
	public void run()
	{	try
		{	for(int i=0;i<5;i++)
			{	System.out.println(alphabets[i]);
			}
		}
		catch(Exception e)
		{	System.out.println(e);
		}
	}
}

public class threadfinal 
{       public static void main(String [] args)
        {       thread1 t1=new thread1();
                 thread2 t2=new thread2();
                 Thread th1=new Thread(t1,"");
                 Thread th2=new Thread(t2,"");
                 try
                 {       th1.start();
                          th2.start();
                 }
                 catch(Exception e)
                 {        System.out.println(e);
                 }
        }
}

Please help with sync in this prog.

[JosAH]

Both threads need to synchronize on a shared object (a lock). They should wait until the other thread notifies them and change roles, i.e. the other thread should wait and the first thread should notify it; before notifying the other thread the thread should print its character; but this entire scenario would be a waste of resources because you can easily avoid this synchronized behaviour in a single thread.

kind regards,

Jos

[wilsonshamim]

Hi ,

Call another thread from the first run() method something like this

class myPrintClass implements Runnable
{

char[] x = {'a','b','c','d','e','f','g','h','i','j'};

@Override
public void run() {
// TODO Auto-generated method stub

for(int i =0; i< 10;i++)
{
System.out.println(i);
myprintAplha ma = new myprintAplha(x[i]);
Thread t2 = new Thread(ma);
t2.start();
}

}

}
class myprintAplha implements Runnable
{

private char cc;
public myprintAplha(char c)
{
cc = c;

}
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println(cc);

}

}

public class print1a {
public static void main(String[] s) throws InterruptedException
{

myPrintClass mp = new myPrintClass();
Thread t1 = new Thread(mp);
t1.start();
}
}

[nothing1010]

I think you should do that: :D

class _Queue
{
	int i = -1;
	boolean busy = false;
	synchronized void set(int i)
	{
		if(!busy) {
			try {
				wait();
			} catch(InterruptedException e) {
			}
		}
		busy = false;
		this.i = i;
		notifyAll();
	}
	synchronized int get() {
		if(busy) {
			try {
				wait();
			} catch(InterruptedException e) {
			}
		}
		busy = true;
		notifyAll();
		return i;
	}
}

class thread1 implements Runnable
{
	_Queue q;
	thread1(_Queue q) {
		this.q = q;
	}
	
	public void run()
	{		
		for(int i=0;i<5;i++) {
			System.out.println(i);
			q.set(i);
			try {
				Thread.sleep(300);
			} catch(InterruptedException e) {
			}
		}
	}
}

class thread2 implements Runnable
{	
	char [] alphabets={'a','b','c','d','e'};
	_Queue q;
	thread2(_Queue q) {
		this.q = q;
	}
	public void run()
	{		
		int j;
		while(true) {
			j = q.get();
			if (j != -1)
				System.out.println(alphabets[j]);
			if (j == 4)
				break;
		}
	}
}

public class threadfinal {       
	public static void main(String [] args) {
		_Queue q = new _Queue();
		thread1 t1=new thread1(q);
        thread2 t2=new thread2(q);
        Thread th1=new Thread(t1,"1");
        Thread th2=new Thread(t2,"2");
        th1.start();
        th2.start();
        try {
        	th1.join();
        	th2.join();
        } catch(InterruptedException e) {
        }
	}
}