Java中的 ConcurrentLinkedQueue addAll() 方法
ConcurrentLinkedQueue 的addAll()方法用于在ConcurrentLinkedQueue的末尾插入作为参数传递给此方法的 Collection 的所有元素。元素的插入与集合迭代器返回的顺序相同。
句法:
public boolean addAll(Collection extends E> c)
参数:此方法接受一个参数c ,该参数表示需要将其元素附加到此 ConcurrentLinkedQueue 末尾的集合。
返回:如果执行了至少一个插入操作,则此方法返回true 。
异常:此方法抛出两个不同的异常:
- NullPointerException – 如果传递的集合或其任何元素为空。
- IllegalArgumentException – 如果传递的集合是这个队列本身。
下面的程序说明了 ConcurrentLinkedQueue 的 addAll() 方法:
示例 1:尝试将数字列表添加到 ConcurrentLinkedQueue。
// Java Program Demonstrate addAll()
// method of ConcurrentLinkedQueue
import java.util.concurrent.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create an ConcurrentLinkedQueue
ConcurrentLinkedQueue
queue = new ConcurrentLinkedQueue();
// Add Numbers to queue
queue.add(4353);
// create a ArrayList of Numbers
ArrayList arraylist = new ArrayList();
// add some numbers to ArrayList
arraylist.add(377139);
arraylist.add(624378);
arraylist.add(654793);
arraylist.add(764764);
arraylist.add(838494);
arraylist.add(632845);
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
// Displaying the existing Collection
System.out.println("Collection to be added: " + arraylist);
// apply addAll() method and passed the arraylist as parameter
boolean response = queue.addAll(arraylist);
// Displaying the existing ConcurrentLinkedQueue
System.out.println("Collection added: " + response);
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
}
}
输出:
ConcurrentLinkedQueue: [4353]
Collection to be added: [377139, 624378, 654793, 764764, 838494, 632845]
Collection added: true
ConcurrentLinkedQueue: [4353, 377139, 624378, 654793, 764764, 838494, 632845]
示例 2:尝试将字符串列表添加到 ConcurrentLinkedQueue。
// Java Program Demonstrate addAll()
// method of ConcurrentLinkedQueue
import java.util.concurrent.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create an ConcurrentLinkedQueue
ConcurrentLinkedQueue
queue = new ConcurrentLinkedQueue();
// Add String to queue
queue.add("Aman");
queue.add("Amar");
// create a ArrayList of Numbers
ArrayList arraylist = new ArrayList();
// add some numbers to ArrayList
arraylist.add("Sanjeet");
arraylist.add("Rabi");
arraylist.add("Debasis");
arraylist.add("Raunak");
arraylist.add("Mahesh");
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
// Displaying the existing Collection
System.out.println("Collection to be added: " + arraylist);
// apply addAll() method and passed the arraylist as parameter
boolean response = queue.addAll(arraylist);
// Displaying the existing ConcurrentLinkedQueue
System.out.println("Collection added: " + response);
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
}
}
输出:
ConcurrentLinkedQueue: [Aman, Amar]
Collection to be added: [Sanjeet, Rabi, Debasis, Raunak, Mahesh]
Collection added: true
ConcurrentLinkedQueue: [Aman, Amar, Sanjeet, Rabi, Debasis, Raunak, Mahesh]
示例 3:显示NullPointerException
// Java Program Demonstrate addAll()
// method of ConcurrentLinkedQueue
import java.util.concurrent.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create an ConcurrentLinkedQueue
ConcurrentLinkedQueue
queue = new ConcurrentLinkedQueue();
// Add String to queue
queue.add("Aman");
queue.add("Amar");
// create a ArrayList which is equal to null
ArrayList arraylist = null;
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
// Displaying the existing Collection
System.out.println("Collection to be added: " + arraylist);
try {
// apply addAll() method and pass the arraylist as parameter
// since the arraylist is null, exception will be thrown
boolean response = queue.addAll(arraylist);
}
catch (NullPointerException e) {
System.out.println("Exception thrown while adding null: " + e);
}
}
}
输出:
ConcurrentLinkedQueue: [Aman, Amar]
Collection to be added: null
Exception thrown while adding null: java.lang.NullPointerException
示例 4:显示 IllegalArgumentException
// Java Program Demonstrate addAll()
// method of ConcurrentLinkedQueue
import java.util.concurrent.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create an ConcurrentLinkedQueue
ConcurrentLinkedQueue
queue = new ConcurrentLinkedQueue();
// Add String to queue
queue.add("Aman");
queue.add("Amar");
// Displaying the existing ConcurrentLinkedQueue
System.out.println("ConcurrentLinkedQueue: " + queue);
try {
// apply addAll() method and passed the queue as parameter
boolean response = queue.addAll(queue);
}
catch (IllegalArgumentException e) {
System.out.println("Exception thrown while adding queue"
+ " to itself when collection is required: " + e);
}
}
}
输出:
ConcurrentLinkedQueue: [Aman, Amar]
Exception thrown
while adding queue to itself
when collection is required: java.lang.IllegalArgumentException
参考: https: Java/util/concurrent/ConcurrentLinkedQueue.html#addAll-java.util.Collection-