Java DelayQueue clear()用法及代码示例

Java中的DelayQueue的clear()方法用于删除当前DelayQueue对象中的所有元素。返回此调用后，队列将为空。延迟中没有过期的队列中的元素会自动从队列中丢弃。

句法：

public void clear()

参数：此方法不带任何参数。

返回值：此方法不返回任何值。

以下示例程序旨在说明上述方法：

// Java program to illustrate the clear() method 
// of DelayQueue class 
  
import java.util.concurrent.DelayQueue; 
import java.util.concurrent.Delayed; 
import java.util.concurrent.TimeUnit; 
  
public class GFG { 
    public static void main(String args[]) 
    { 
        // Create a DelayQueue instance 
        DelayQueue<Delayed> queue = new DelayQueue<Delayed>(); 
  
        // Create an Object of type Delayed 
        Delayed obj = new Delayed() { 
            public long getDelay(TimeUnit unit) 
            { 
                return 24; // some value is returned 
            } 
  
            public int compareTo(Delayed o) 
            { 
                if (o.getDelay(TimeUnit.DAYS) >  
                                  this.getDelay(TimeUnit.DAYS)) 
                    return 1; 
                else if (o.getDelay(TimeUnit.DAYS) ==  
                                  this.getDelay(TimeUnit.DAYS)) 
                    return 0; 
                return -1; 
            } 
        }; 
  
        // Add the obj to the queue 
        queue.add(obj); 
  
        // Check if queue is empty 
        System.out.println("Is queue empty() : "
                           + queue.isEmpty()); 
  
        // Remove all elements from queue 
        // uing clear() method 
        queue.clear(); 
  
        // Check if queue is empty 
        System.out.println("Is queue empty after calling clear() : "
                           + queue.isEmpty()); 
    } 
}

输出：

Is queue empty() : false
Is queue empty after calling clear() : true

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注：本文由纯净天空筛选整理自psil123大神的英文原创作品 DelayQueue clear() method in Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。