Using BlockingQueue for Producer - Consumer

Question

I am trying to use the BlockingQueue in a Producer-Consumer
pattern instead of creating a Q and using wait() and notify().
The output what I want is:
Put : 1
Got : 1
Put : 2
Got : 2But the output I am getting is :
Put 0
Put 2
Put 4
Got 3
Got 5
Got 7This is my Java code using BlockingQueue
Have I missed any point?
Can I not use BlockingQueue instead of using wait() and notify()?
class Producer2 implements Runnable {
     private BlockingQueue<String> queue;
     public Producer2(BlockingQueue<String> q){
          this.queue = q;
     public void run(){
          int i=0;
          while(true){
               try {
                    String putValue = Integer.toString(i++);
                    queue.put(Integer.toString(i++));
                    System.out.println("Put " + putValue);
               } catch (InterruptedException e) {
                    e.printStackTrace();
class Consumer2 implements Runnable {
     private BlockingQueue<String> queue;
     public Consumer2(BlockingQueue<String> q){
          this.queue = q;
          public void run(){
               while(true){
                    try {
                         String value = queue.take();
                         System.out.println("Got " + value);
                    } catch (InterruptedException e) {
                         e.printStackTrace();
public class ProducerConsumer_BlockingQueue_Test {
       public static void main(String[] args) throws Exception {
              BlockingQueue<String> q =
                 new LinkedBlockingQueue<String>();
              Thread p1 = new Thread(new Producer2(q));
              Thread c1 = new Thread(new Consumer2(q));
              p1.start();
              c1.start();
}

Answer 1

Nothing to do with the queue, in your producer you're incrementing i twice, once after seting putValue, again after queuing the item.