The take() method of LinkedBlockingQueue is used to retrieve and remove the head of this queue. If the queue is empty then it will wait until an element becomes available. This method is more efficient if working on threads and using LinkedBlockingQueue in that process. So the thread that initially calls take() goes to sleep if there is no element available, letting other threads do whatever they need to do.
Syntax:
public E take() throws InterruptedException
Return Value: This method returns value at the head of this LinkedBlockingQueue. If the queue is empty then it will wait until an element becomes available.
Exception: This method throws following exceptions:
- InterruptedException– When the interruption occurs at time of waiting for an element to become available if queue is empty.
Below programs illustrates take() method of LinkedBlockingQueue class:
Program 1: Remove operation on head of LinkedBlockingQueue using take().
Java
// Java Program Demonstrate take()// method of LinkedBlockingQueueimport java.util.concurrent.LinkedBlockingQueue;public class GFG { public static void main(String[] args) throws InterruptedException { // define capacity of LinkedBlockingQueue int capacityOfQueue = 4; // create object of LinkedBlockingQueue LinkedBlockingQueue<String> linkedQueue = new LinkedBlockingQueue<String>(capacityOfQueue); // Add element to LinkedBlockingQueue linkedQueue.add("Ravi"); linkedQueue.add("Suraj"); linkedQueue.add("Harsh"); linkedQueue.add("Sayan"); // print elements of queue System.out.println("Items in Queue are " + linkedQueue); // remove two elements from queue from head // Applying take() method on queue to remove element String removedItem1 = linkedQueue.take(); // print removedItem and queue System.out.println("Removed Item from head is " + removedItem1); // print elements of queue after removing first item System.out.println("Remaining Items in Queue are " + linkedQueue); // Applying take() method on queue to remove another element String removedItem2 = linkedQueue.take(); // print removedItem and queue System.out.println("Removed Item from head is " + removedItem2); // print elements of queue after removing first item System.out.println("Remaining Items in Queue are " + linkedQueue); }} |
Output:
Items in Queue are [Ravi, Suraj, Harsh, Sayan] Removed Item from head is Ravi Remaining Items in Queue are [Suraj, Harsh, Sayan] Removed Item from head is Suraj Remaining Items in Queue are [Harsh, Sayan]
Program 2: Remove Employee object from LinkedBlockingQueue using take().
Java
// Java Program Demonstrate take()// method of LinkedBlockingQueueimport java.util.concurrent.LinkedBlockingQueue;public class GFG { public void takeDemo() throws InterruptedException { // define capacity of LinkedBlockingQueue int capacityOfQueue = 5; // create object of LinkedBlockingQueue LinkedBlockingQueue<Employee> linkedQueue = new LinkedBlockingQueue<Employee>(capacityOfQueue); // Add element to LinkedBlockingQueue Employee emp1 = new Employee("Ravi", "Tester", "39000"); Employee emp2 = new Employee("Sanjeet", "Manager", "98000"); // Add Employee Objects to linkedQueue linkedQueue.add(emp1); linkedQueue.add(emp2); // remove elements from the queue // and follow this process again and again // until the queue becomes empty while (linkedQueue.size() != 0) { // Remove Employee item from LinkedBlockingQueue // using take() Employee removedEmp = linkedQueue.take(); // print removedItem System.out.println("Removed Item is :"); System.out.println("Employee Name - " + removedEmp.name); System.out.println("Employee Position - " + removedEmp.position); System.out.println("Employee Salary - " + removedEmp.salary); // find size of linkedQueue int size = linkedQueue.size(); // print remaining capacity value System.out.println("\nSize of list :" + size + "\n"); } } // create an Employee Object with name, // position and salary as an attribute public class Employee { public String name; public String position; public String salary; Employee(String name, String position, String salary) { this.name = name; this.position = position; this.salary = salary; } @Override public String toString() { return "Employee [name=" + name + ", position=" + position + ", salary=" + salary + "]"; } } // Main Method public static void main(String[] args) { GFG gfg = new GFG(); try { gfg.takeDemo(); } catch (Exception e) { e.printStackTrace(); } }} |
Output:
Removed Item is : Employee Name - Ravi Employee Position - Tester Employee Salary - 39000 Size of list :1 Removed Item is : Employee Name - Sanjeet Employee Position - Manager Employee Salary - 98000 Size of list :0
