The clear() method of ArrayBlockingQueue removes all the elements from the queue. The queue becomes empty after calling this method.

Syntax:

public void clear()

Program to show ArrayBlockingQueue clear() method

Let’s have a look at the program.

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;

public class ArrayBlockingQueueClearExample {

        public static void main(String[] args) {
                int capacity = 5;
                BlockingQueue salaries = new ArrayBlockingQueue<>(capacity);
                salaries.add(20000);
                salaries.add(25000);
                salaries.add(15000);
                salaries.add(17000);
                salaries.add(19000);
                System.out.println("Queue elements: \n" + salaries);
                salaries.clear();
                System.out.println("Queue after clearing all elements: \n" + salaries);
        }
}

Output:

Queue elements: 
[20000, 25000, 15000, 17000, 19000]
Queue after clearing all elements: 
[]

Example:

The below example shows how clear() method removes all the user-defined objects from the queue.

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;

public class ClearDemo {

        public static void main(String[] args) {

                int capacity = 5;
                BlockingQueue employees = new ArrayBlockingQueue<>(capacity);
                employees.add(new Employee(101, "Adam"));
                employees.add(new Employee(102, "Smith"));
                employees.add(new Employee(103, "John"));
                employees.add(new Employee(104, "Ricky"));

                for (Employee employee : employees) {
                        System.out.println(employee);
                }
                employees.clear();
                System.out.println("Queue after clearing all elements: \n" + employees);
        }
}

Output:

Employee [employeeId=101, employeeName=Adam]
Employee [employeeId=102, employeeName=Smith]
Employee [employeeId=103, employeeName=John]
Employee [employeeId=104, employeeName=Ricky]
Queue after clearing all elements: 
[]

That’s all regarding the ArrayBlockingQueue clear method in Java. Please share if you find this article helpful.