Método ArrayBlockingQueue take() en Java

ArrayBlockingQueue es una cola de bloqueo limitada que almacena los elementos respaldados internamente por una array.

• La clase ArrayBlockingQueue es miembro de Java Collections Framework.
• Acotado significa que tendrá un tamaño fijo, no puede almacenar el número de elementos más que la capacidad de la cola.
• La cola también sigue la regla FIFO (primero en entrar, primero en salir) para almacenar y eliminar elementos de la cola.
• Si intenta colocar un elemento en una cola llena o tomar un elemento de una cola vacía, la cola lo bloqueará.

El método take() se usa para recuperar y eliminar el encabezado de esta cola. Si la cola está vacía, esperará hasta que un elemento esté disponible. Sintaxis:

public E take()throws InterruptedException

Parámetros: El método no toma ningún parámetro. 

Valor devuelto: el método devuelve el valor al principio de esta cola. 

Excepción: el método arroja InterruptedException si se interrumpe mientras espera. 

Los siguientes programas ilustran el método take() de ArrayBlockingQueue: 

Programa 1 : 

// Program to demonstrate take() method of ArrayBlockingQueue
 
import java.util.concurrent.ArrayBlockingQueue;
 
public class GFG {
 
public static void main(String[] args)
                  throws InterruptedException{
    // Define capacity of ArrayBlockingQueue
    int capacity = 5;
     
    // Create object of ArrayBlockingQueue
    ArrayBlockingQueue<Integer> queue =
        new ArrayBlockingQueue<Integer>(capacity);
     
    // Add elements to ArrayBlockingQueue
    queue.add(23);
    queue.add(32);
    queue.add(45);
    queue.add(12);
     
    // Print queue after adding numbers
    System.out.print("After adding numbers Queue: "
                                                +queue);
 
        // Apply take() method
    int head=queue.take();
     
    // Print head of queue using take() method
    System.out.println("Head of queue removed is "
                                                +head);
    System.out.print("After removing head. Queue: ");
    System.out.println(queue);
     
    // Apply take() method
    head = queue.take();
     
    // Print head of queue using take() method
    System.out.println("Head of queue removed is "
                                               + head);
    System.out.print("After removing head. Queue: ");
    System.out.println(queue);
     
}
}

After adding numbers Queue: [23, 32, 45, 12]Head of queue removed is 23
After removing head. Queue: [32, 45, 12]
Head of queue removed is 32
After removing head. Queue: [45, 12]

Programa 2: 

// Program to demonstrate take() method of ArrayBlockingQueue
 
import java.util.concurrent.ArrayBlockingQueue;
 
public class GFG {
 
    // Create a User Object with name
    // and age as the attribute
    public class User {
 
        public String name;
        public String age;
        User(String name, String age)
        {
            this.name = name;
            this.age = age;
        }
    }
 
    // Main Method
    public static void main(String[] args)
                        throws InterruptedException
    {
        GFG gfg = new GFG();
        gfg.takeMethodExample();
    }
 
    // Method to give example of take function
    public void takeMethodExample()
                        throws InterruptedException
    {
 
        // define capacity of ArrayBlockingQueue
        int capacity = 5;
 
        // create object of ArrayBlockingQueue
        ArrayBlockingQueue<User> queue =
               new ArrayBlockingQueue<User>(capacity);
 
        // create user objects
        User user1 = new User("Aman", "24");
        User user2 = new User("Amar", "23");
        User user3 = new User("Sanjeet", "25");
        User user4 = new User("Suvo", "26");
        User user5 = new User("Ravi", "22");
 
        // Add Objects to ArrayBlockingQueue
        queue.offer(user1);
        queue.offer(user2);
        queue.offer(user3);
        queue.offer(user4);
        queue.offer(user5);
 
        // find take() of queue
        User head = queue.take();
 
        // print head
        System.out.println("Details of User Removed"
                    +" After Applying take() Method");
        System.out.println("User Name : " + head.name);
        System.out.println("User Age : " + head.age);
 
        // find take() of queue
        head = queue.take();
 
        // print head
        System.out.println("Details of User Removed"+
                      " After Applying take() Method");
        System.out.println("User Name : " + head.name);
        System.out.println("User Age : " + head.age);
    }
}

Details of User Removed After Applying take() Method
User Name : Aman
User Age : 24
Details of User Removed After Applying take() Method
User Name : Amar
User Age : 23

Referencia: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ArrayBlockingQueue.html#take()