How to add syncronization properly Java

Question

As the integers are produced the Consumer thread sums their value (1+2+3…+10=55)

Producer thread generates integers from 1 to 10

The program is meant to produce

Answer 1

Just use BlockingQueue as a container for elements that producer produces and consumer consumes:

public class UsingSharedInt {

       private BlockingQueue q = new ArrayBlockingQueue<>(100);

       public void setSharedInt( int val )
       {
          System.err.println( Thread.currentThread().getName() +
          " setting sharedInt to " + val );
          q.add(val); // puts val into the queue
       }

       public int getSharedInt()
       {
         int val = q.take(); // waits for element to become available in queue, then returns one
         System.err.println( Thread.currentThread().getName() +
         " retrieving sharedInt value " + val);
         return val;
       }
   }