Java ConcurrentSkipListSet removeAll()用法及代码示例

java.util.concurrent.ConcurrentSkipListSet的removeAll()方法是Java中的一个内置函数，该函数从该集合中移除指定集合中包含的所有元素。如果指定的集合也是一个集合，则此操作会有效地修改此集合，以使其值为两个集合的非对称集合差异。

用法:

public boolean removeAll(Collection> c)

参数：该函数接受单个参数c

返回值：如果此设置由于调用而改变，则函数返回true。

异常：该函数引发以下异常：

ClassCastException–如果该集合中一个或多个元素的类型与指定的集合不兼容
NullPointerException –如果指定的集合或其任何元素为空

以下示例程序旨在说明ConcurrentSkipListSet.removeAll()方法：

示例1:

// Java program to demonstrate removeAll() 
// method of ConcurrentSkipListSet 
  
import java.util.concurrent.*; 
import java.util.ArrayList; 
import java.util.List; 
  
class ConcurrentSkipListSetremoveAllExample1 { 
    public static void main(String[] args) 
    { 
  
        // Initializing the List 
        List<Integer> list = new ArrayList<Integer>(); 
  
        // Adding elements in the list 
        for (int i = 1; i <= 10; i += 2) 
            list.add(i); 
  
        // Contents of the list 
        System.out.println("Contents of the list: " + list); 
  
        // Initializing the set 
        ConcurrentSkipListSet<Integer> 
            set = new ConcurrentSkipListSet<Integer>(); 
  
        // Adding elements in the set 
        for (int i = 1; i <= 10; i++) 
            set.add(i); 
  
        // Contents of the set 
        System.out.println("Contents of the set: " + set); 
  
        // Remove all elements from the set which are in the list 
        set.removeAll(list); 
  
        // Contents of the set after removal 
        System.out.println("Contents of the set after removal: "
                           + set); 
    } 
}

输出：

Contents of the list: [1, 3, 5, 7, 9]
Contents of the set: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Contents of the set after removal: [2, 4, 6, 8, 10]

示例2:在removeAll()中显示NullPOinterException的程序。

// Java program to demonstrate removeAll() 
// method of ConcurrentSkipListSet 
  
import java.util.concurrent.*; 
import java.util.ArrayList; 
import java.util.List; 
  
class ConcurrentSkipListSetremoveAllExample1 { 
    public static void main(String[] args) 
    { 
  
        // Initializing the set 
        ConcurrentSkipListSet<Integer> 
            set = new ConcurrentSkipListSet<Integer>(); 
  
        // Adding elements in the set 
        for (int i = 1; i <= 10; i++) 
            set.add(i); 
  
        // Contents of the set 
        System.out.println("Contents of the set: " + set); 
  
        try { 
            // Remove all elements from the set which are null 
            set.removeAll(null); 
        } 
        catch (Exception e) { 
            System.out.println("Exception: " + e); 
        } 
    } 
}

输出：

Contents of the set: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Exception: java.lang.NullPointerException

参考：

相关用法

注：本文由纯净天空筛选整理自rupesh_rao大神的英文原创作品 ConcurrentSkipListSet removeAll() 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。