synchroized_with_different_object.java

class TicketCounter extends Thread {
  TicketingSystem ticketingSystem;
  
  public TicketCounter(String name) {
    this.setName(name);
    start();
  }
  @Override
  public void run() {
    System.out.println(TicketingSystem.getNextAvailableTicket(this));  
  }
}

class TicketingSystem {
  static final Ticket number1 = new Ticket("Number1", "open");
  static final Ticket number2 = new Ticket("Number2", "open");
  
  static Ticket[] numberList = new Ticket[] {number1, number2};
  
  public static  String getNextAvailableTicket(Thread ticketCounter) {
    String availableNumber = null;
    try {
      synchronized(ticketCounter){
        for (Ticket number: numberList) {
          if(number.getStatus() == "open") {
            number.setStatus("pending"); // changing the state of the object
            
            System.out.printf("Thread name %s - number found %s \n",Thread.currentThread().getName(), number.getName());
            Thread.sleep(5000); // assume processing some business logic
            number.setStatus("open"); // decide to put it back due to some error
            
            availableNumber = number.getName();
            break;
          }
        }      
      }
    } catch (InterruptedException e) {
      e.printStackTrace();
    }

    return availableNumber;
  }
}