Producer and Consumer with wait() and notify()

package com.zybnet.so;


public class Main {

    public static void main(String[] args) throws Exception{
        RoundRobinBuffer buf = new RoundRobinBuffer();
        Thread produce = new Thread(new Producer(buf));
        Thread consume = new Thread(new consumer(buf));

        produce.start();
        consume.start();

        produce.join();
        consume.join();

        System.out.println("Ok finished");
    }

    static class RoundRobinBuffer {
        private double buff[];
        private volatile int nextWrite;
        private volatile int nextRead;

        public RoundRobinBuffer(){
            buff = new double[1000];
            nextWrite = 0;
            nextRead = 0;
        }

        public synchronized void add(double add) throws InterruptedException{
            if((nextWrite + 1) % 1000 == nextRead)
                wait();
            buff[nextWrite] = add;
            nextWrite = (nextWrite+1)%1000;
            notify();
        }

        public synchronized double get()throws InterruptedException{
            if(nextRead == nextWrite)
                   wait();
            double temp = buff[nextRead];
            nextRead = (nextRead+1)%1000;
            notify();
            return temp;
        }

    }

    public static class consumer implements Runnable{
        private RoundRobinBuffer consumBuff;

        public consumer (RoundRobinBuffer buff){
            consumBuff = buff;
        }

        public void run() {
            for(int i = 1; i<=1000000; i++) {
                try {
                    System.out.println("Consumer has consumed " + consumBuff.get());
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
            System.out.println("!!!Consumer has consumed all items!!!");
        }
    }

    public static class Producer implements Runnable{
        private RoundRobinBuffer produceBuff;

        public Producer (RoundRobinBuffer buff){
            produceBuff = buff;
        }

        public void run(){
            for(int i = 1; i<=1000000; i++) {
                try {
                    produceBuff.add(i);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                if((i % 100000) == 0)
                    System.out.println("Producer has produced "+ i );
            }
            System.out.println("Producer has produced all items.");
        }

    }
}