集合类unmodifiableList()方法 (Collections Class unmodifiableList() method)

• unmodifiableList() method is available in java.util package.

  unmodifiableList()方法在java.util包中可用。

• unmodifiableList() method is used to get a non-modifiable view of the given List (l).

  unmodifiableList()方法用于获取给定列表(l)的不可修改视图。

• unmodifiableList() method is a static method, it is accessible with the class name and if we try to access the method with the class object then also we will not get any error.

  unmodifiableList()方法是一个静态方法，可以使用类名进行访问，如果尝试使用类对象访问该方法，那么也不会出现任何错误。

• unmodifiableList() method does not throw an exception at the time of returning an unmodifiable view of the given list.

  返回给定列表的不可修改视图时， unmodifiableList()方法不会引发异常。

Syntax:

句法：

public static List unmodifiableList(List l) ;

Parameter(s):

参数：

• List l – represents the list object for which a non-modifiable view is to be retrieved.

  列表l –表示要为其检索不可修改视图的列表对象。

Return value:

返回值：

The return type of this method is List, it returns an unmodifiable view of the given list.

此方法的返回类型为List ，它返回给定列表的不可修改视图。

Example:

例：

// Java program to demonstrate the example // of List unmodifiableList()// method of Collectionsimport java.util.*;public class UnmodifiableListOfCollections {
       public static void main(String args[]) {
           // Instantiates a linked list object        List ll = new LinkedList();        // By using add() method is to add        // objects in a linked list         ll.add(10);        ll.add(20);        ll.add(30);        ll.add(40);        ll.add(50);        // Display Linked list        System.out.println("LinkedList: " + ll);        // By using unmodifiableList() method is to        // represent the linked lis in an unmodifiable view        ll = Collections.unmodifiableList(ll);        // We will get an exception when we        // try to add an object in an unmodifiable        // linked list        /* ll.add(60);*/    }}

Output

输出量

LinkedList: [10, 20, 30, 40, 50]

翻译自: