class Buffer {
    private String[] queue;
    private int number;

    public Buffer (int size) {
        queue = new String[size];
        number = 0;
    } // Buffer

    public synchronized void put(String str) {

	while(number == queue.length) {
	    try {
		System.out.println("Buffer.put: Väntar...");
		wait();
	    }
	    catch (InterruptedException e) {
		System.out.println("Buffer.put: Oj!");
	    }
	}

        queue[number++] = str;

	notify();

    } // put

    public synchronized String get() {

	while(number == 0) {
	    try {
		System.out.println("Buffer.get: Väntar...");
		wait();
	    }
	    catch (InterruptedException e) {
		System.out.println("Buffer.get: Oj!");
	    }
	}

        String s = queue[0];
        for (int i = 1; i < number; ++i)
            queue[i - 1] = queue[i];
        --number;

	notify();

        return s;
    } // get
} // class Buffer

class WriterThread extends Thread {
    Buffer b;
    public WriterThread(Buffer b) {
        this.b = b;
    }
    public void run() {
        int nrReps = 0;
        while (true) {
            String s = "Sträng nummer " + ++nrReps;
            System.out.println("WriterThread: Lagrar " + s);
            b.put(s);
        }
    } // run
} // class WriterThread

class ReaderThread extends Thread {
    Buffer b;
    public ReaderThread(Buffer b) {
        this.b = b;
    }
    public void run() {
        while (true) {
            String s = b.get();
            System.out.println("ReaderThread: Hämtade " + s);
        }
    } // run
} // class ReaderThread

public class NotifyExample {
    public static void main(String[] args) {
        Buffer b = new Buffer(100);
        WriterThread w = new WriterThread(b);
        ReaderThread r = new ReaderThread(b);
        w.start();
        r.start();
    } // main
} // class NotifyExample