How do threads communicate with each other in Java?

Inter-thread communication involves the communication of threads with each other. The three methods that are used to implement inter-thread communication in Java

wait()

This method causes the current thread to release the lock. This is done until a specific amount of time has passed or another thread calls the notify() or notifyAll() method for this object.

notify()

This method wakes a single thread out of multiple threads on the current object’s monitor. The choice of thread is arbitrary.

notifyAll()

This method wakes up all the threads that are on the current object’s monitor.

Example

class BankClient {
   int balAmount = 5000;
   synchronized void withdrawMoney(int amount) {
      System.out.println("Withdrawing money");
      balAmount -= amount;
      System.out.println("The balance amount is: " + balAmount);
   }
   synchronized void depositMoney(int amount) {
      System.out.println("Depositing money");
      balAmount += amount;
      System.out.println("The balance amount is: " + balAmount);
      notify();
   }
}
public class ThreadCommunicationTest {
   public static void main(String args[]) {
      final BankClient client = new BankClient();
      new Thread() {
         public void run() {
            client.withdrawMoney(3000);
         }
      }.start();
      new Thread() {
         public void run() {
           client.depositMoney(2000);
         }
      }.start();
   }
}

Output

Withdrawing money
The balance amount is: 2000
Depositing money
The balance amount is: 4000

Raja

Published on 03-Sep-2019 11:09:05