El método take() de la interfaz BlockingQueue se usa para recuperar y eliminar el encabezado de esta cola. Si la cola está vacía, esperará hasta que un elemento esté disponible. Este método es más eficiente si se trabaja en subprocesos y se usa BlockingQueue en ese proceso. Entonces, el subproceso que inicialmente llama a take() se duerme si no hay ningún elemento disponible, lo que permite que otros subprocesos hagan lo que necesiten hacer.
Sintaxis:
public E take() throws InterruptedException
Valor devuelto: este método devuelve valor al principio de esta BlockingQueue. Si la cola está vacía, esperará hasta que un elemento esté disponible.
Excepción: este método arroja las siguientes excepciones:
- InterruptedException : cuando la interrupción se produce en el momento de esperar a que un elemento esté disponible si la cola está vacía.
Nota : El método take() de BlockingQueue se ha heredado de la clase Queue en Java.
Los siguientes programas ilustran el método take() de la interfaz BlockingQueue:
Programa 1:
Java
// Java Program Demonstrate take() // method of BlockingQueue import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.BlockingQueue; public class GFG { public static void main(String[] args) throws InterruptedException { // define capacity of BlockingQueue int capacityOfQueue = 4; // create object of BlockingQueue BlockingQueue<String> BQ = new LinkedBlockingQueue<String>(capacityOfQueue); // Add element to BlockingQueue BQ.add("Ravi"); BQ.add("Suraj"); BQ.add("Harsh"); BQ.add("Sayan"); // print elements of queue System.out.println("Items in Queue are " + BQ); // remove two elements from queue from head // Applying take() method on queue to remove element String removedItem1 = BQ.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 " + BQ); // Applying take() method on queue to remove another element String removedItem2 = BQ.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 " + BQ); } }
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]
Programa 2:
Java
// Java Program Demonstrate take() // method of BlockingQueue import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.BlockingQueue; public class GFG { public void takeDemo() throws InterruptedException { // define capacity of BlockingQueue int capacityOfQueue = 5; // create object of BlockingQueue BlockingQueue<Employee> BQ = new LinkedBlockingQueue<Employee>(capacityOfQueue); // Add element to BlockingQueue Employee emp1 = new Employee("Ravi", "Tester", "39000"); Employee emp2 = new Employee("Sanjeet", "Manager", "98000"); // Add Employee Objects to BQ BQ.add(emp1); BQ.add(emp2); // remove elements from the queue // and follow this process again and again // until the queue becomes empty while (BQ.size() != 0) { // Remove Employee item from BlockingQueue // using take() Employee removedEmp = BQ.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 BQ int size = BQ.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(); } } }
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