import java.util.*;

public class Producer implements Runnable
{
    static final int MAXQUEUE = 5;
    private List messages = new ArrayList();

    public void run() {
		while ( true ) {
			putMessage();
            try { 
				Thread.sleep( 1000 ); 
			} catch ( InterruptedException e ) { }
		}
    }

    private synchronized void putMessage() 
	{
        while ( messages.size() >= MAXQUEUE )
			try {
				wait();
			} catch( InterruptedException e ) { }

        messages.add( new java.util.Date().toString() );
        notify();
    }

    // called by Consumer
    public synchronized String getMessage()
	{
        while ( messages.size() == 0 )
			try {
				notify();
				wait();
			} catch( InterruptedException e ) { }
        String message = (String)messages.remove(0);
		notify();
        return message;
    }
}