Java PriorityBlockingQueue remainingCapacity()方法

PriorityBlockingQueue 的 remainCapacity 方法用于检查 还有多少元素可以被插入这个队列 但是由于PriorityBlockingQueue是无界的，这个方法总是返回 Integer.MAX_VALUE ，因为PriorityBlockingQueue是没有容量限制的。

语法：

public int remainingCapacity()

返回值： Integer.MAX_VALUE 总是

以下程序说明了PriorityBlockingQueue中的remainCapacity()方法：

程序1：

// Java Program Demonstrate remainingCapacity()
// method of PriorityBlockingQueue
 
import java.util.concurrent.PriorityBlockingQueue;
 
public class GFG {
    public static void main(String[] args)
    {
        // define capacity of PriorityBlockingQueue
        int capacityOfQueue = 7;
 
        // create object of PriorityBlockingQueue
        PriorityBlockingQueue<Integer> pbq
            = new PriorityBlockingQueue<Integer>(capacityOfQueue);
 
        // Add element to PriorityBlockingQueue
        pbq.put(1);
        pbq.put(2);
        pbq.put(3);
        pbq.put(4);
 
        // find remaining Capacity  of pbq
        // using remainingCapacity() method
 
        // The initial capacity was set to 7
        // by passing as parameter in constructor
        // But this method will return Integer.MAX_VALUE
        int remainingCapacity = pbq.remainingCapacity();
 
        // print result
        System.out.println("Queue:  " + pbq);
        System.out.println("Remaining Capacity: " + remainingCapacity);
    }
}

输出

Queue:  [1, 2, 3, 4]
Remaining Capacity: 2147483647

程序2： 使用字符串
来演示restainingCapacity()。

// Java Program Demonstrate remainingCapacity()
// method of PriorityBlockingQueue
 
import java.util.concurrent.PriorityBlockingQueue;
 
public class GFG {
    public static void main(String[] args)
    {
 
        // create object of PriorityBlockingQueue
        PriorityBlockingQueue<String> pbq
            = new PriorityBlockingQueue<String>();
 
        // Add element to PriorityBlockingQueue
        pbq.put("Geeks");
        pbq.put("forGeeks");
        pbq.put("A Computer");
        pbq.put("Portal");
 
        // find remaining Capacity  of pbq
        // using remainingCapacity() method
        int remainingCapacity = pbq.remainingCapacity();
 
        // print result
        System.out.println("Queue:  " + pbq);
        System.out.println("Remaining Capacity: " + remainingCapacity);
    }
}

输出

Queue:  [A Computer, Portal, Geeks, forGeeks]
Remaining Capacity: 2147483647