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 add a temp int in Consumer to see if it's different from the last one.

int val, sum, tmp = 0;
do {
// sleep for a random interval
  try { 
     Thread.sleep( (int) ( Math.random() * 3000 ) ); 
  }catch( InterruptedException e ) {
     System.err.println( e.toString() );
  }
  val = cHold.getSharedInt();
  if(val!=tmp){
    sum += val;
  }
  tmp = val;
} while ( val != 10 );