Java中的 BlockingQueue remove() 方法及示例

BlockingQueue 的remove(Object obj)方法仅从该BlockingQueue中移除作为参数传递的给定对象的一个实例（如果存在）。它删除一个元素 e 使得 obj.equals(e) 并且如果这个队列包含元素 e 的一个或多个实例。如果此队列包含现在从 BlockingQueue 中删除的元素，则此方法返回 true。

句法：

public boolean remove(Object o)

参数：此方法接受一个强制参数obj ，它是要从 BlockingQueue 中删除的元素。

返回值：如果此队列包含现在从 BlockingQueue 中删除的元素，则此方法返回true 。如果 BlockingQueue 不包含元素obj ，则此方法返回false 。

注意： BlockingQueue的remove()方法继承自Java中的Queue类。

下面的程序说明了 BlockingQueue 类的 remove(Object obj) 方法：

方案一：

// Java Program Demonstrate  remove(Object obj)
// 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 BQ
            = new LinkedBlockingQueue(capacityOfQueue);
  
        // Add element using put() method
        BQ.put("Karan");
        BQ.put("Suraj");
        BQ.put("Harsh");
        BQ.put("Rahul");
  
        // print elements of queue
        System.out.println("Items in Queue are " + BQ);
  
        // try to remove Karan from Queue using remove()
        boolean try1 = BQ.remove("Karan");
        // Print result of remove()
        System.out.println("String name Karan is removed :"
                           + try1);
  
        // try to remove Sunny from Queue using remove()
        boolean try2 = BQ.remove("Sunny");
        // Print result of remove()
        System.out.println("String name Sunny is removed :"
                           + try2);
  
        // try to remove Sunny from Queue using remove()
        boolean try3 = BQ.remove("Harsh");
        // Print result of remove()
        System.out.println("String name Harsh is removed :"
                           + try2);
  
        // print queue
        System.out.println("After Removing Some Elements:");
        System.out.println("Items in Queue are " + BQ);
    }
}

输出：

Items in Queue are [Karan, Suraj, Harsh, Rahul]
String name Karan is removed :true
String name Sunny is removed :false
String name Harsh is removed :false
After Removing Some Elements:
Items in Queue are [Suraj, Rahul]

方案一：

// Java Program Demonstrate remove(object obj)
// method of BlockingQueue
  
import java.util.Iterator;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
  
    public void removeDemo() throws InterruptedException
    {
        // define capacity of BlockingQueue
        int capacityOfQueue = 5;
  
        // create object of BlockingQueue
        BlockingQueue BQ
            = new LinkedBlockingQueue(capacityOfQueue);
  
        // Add element to LinkedBlockingQueue
        Employee emp1 = new Employee("Ranjeet", "Tester", "29000", 27);
        Employee emp2 = new Employee("Sanjeet", "Manager", "98000", 34);
        Employee emp3 = new Employee("Karan", "Analyst", "44000", 30);
  
        // Add Employee Objects to BQ Using put(E e)
        BQ.put(emp1);
        BQ.put(emp2);
        BQ.put(emp3);
  
        // print details of BQ
        System.out.println("Before removing Elements");
        Iterator itr = BQ.iterator();
        while (itr.hasNext())
            System.out.println(itr.next());
  
        // remove employee2 name Sanjeet from BQ
        // Using remove(Object obj) method
        BQ.remove(emp2);
  
        // Also remove Ranjeet employee1 from BQ
        // Using remove(Object obj) method
        BQ.remove(emp1);
  
        // print details of BQ
        System.out.println("After removing Some Elements");
        itr = BQ.iterator();
        while (itr.hasNext())
            System.out.println(itr.next());
    }
  
    // create an Employee Object with name,
    // position, salary and age as attributes
    public class Employee {
  
        public String name;
        public String position;
        public String salary;
        public int Age;
        Employee(String name, String position,
                 String salary, int age)
        {
            this.name = name;
            this.position = position;
            this.salary = salary;
            this.Age = age;
        }
  
        @Override
        public String toString()
        {
            return "Employee [name=" + name + ", position="
                + position + ", salary=" + salary + ", Age=" + Age + "]";
        }
    }
  
    // Main Method
    public static void main(String[] args)
    {
        GFG gfg = new GFG();
        try {
            gfg.removeDemo();
        }
        catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

输出：

Before removing Elements
Employee [name=Ranjeet, position=Tester, salary=29000, Age=27]
Employee [name=Sanjeet, position=Manager, salary=98000, Age=34]
Employee [name=Karan, position=Analyst, salary=44000, Age=30]
After removing Some Elements
Employee [name=Karan, position=Analyst, salary=44000, Age=30]

参考： https: Java Java.lang.Object)