Java Collections unmodifiableNavigableSet()用法及代碼示例

Java Collections 類的 unmodifiableNavigableSet() 方法用於獲取指定可導航集的不可修改視圖。

用法

以下是 unmodifiableNavigableSet() 方法的聲明：

public static <T> NavigableSet<T> unmodifiableNavigableSet(NavigableSet<T> s)

參數

參數	描述	必需/可選
s	它是將返回不可修改視圖的可導航集。	Required

unmodifiableNavigableSet() 方法返回指定可導航集的不可修改視圖。

異常

兼容版本

Java 1.8 及以上

例子1

import java.util.*;
public class CollectionsUnmodifiableNavigableSetExample1 {
	public static void main(String[] args) {
		NavigableSet<Integer> set = new TreeSet<>();
            Collections.addAll(set, 1,2,3,4,5);
            System.out.println("Initial Set:" + set);
            NavigableSet<Integer> set2 = Collections.unmodifiableNavigableSet(set);
            System.out.println("Unmodifiable Navigable Set:" + set2);
            //Modifying the original set
            set.add(15);
            System.out.println("Unmodifiable Navigable Set:" + set2);
	      }
}

輸出：

Initial Set:[1, 2, 3, 4, 5]
Unmodifiable Navigable Set:[1, 2, 3, 4, 5]
Unmodifiable Navigable Set:[1, 2, 3, 4, 5, 15]

例子2

import java.util.*;
public class CollectionsUnmodifiableNavigableSetExample2 {
	public static void main(String[] args) {
		NavigableSet<String> set = new TreeSet<>();
            Collections.addAll(set, "Google", "Facebook", "Instagram");
            System.out.println("Initial Set:" + set);
            NavigableSet<String> set2 = Collections.unmodifiableNavigableSet(set);
            System.out.println("Unmodifiable Navigable Set:" + set2);
            //Modifying the original set
            set.add("Twitter");
            System.out.println("Unmodifiable Navigable Set:" + set2);
	      }
}

輸出：

Initial Set:[Facebook, Google, Instagram]
Unmodifiable Navigable Set:[Facebook, Google, Instagram]
Unmodifiable Navigable Set:[Facebook, Google, Instagram, Twitter]

例子3

import java.util.*;
public class CollectionsUnmodifiableNavigableSetExample3 {
	public static void main(String[] args) {
		NavigableSet<Integer> set = new TreeSet<>();
            Collections.addAll(set, 11, 13, 17);
            System.out.println("Original Set:" + set);
            NavigableSet<Integer> set2 = Collections.unmodifiableNavigableSet(set);
            set2.add(19);
	      }
}

輸出：

Original Set:[11, 13, 17]
Exception in thread "main" java.lang.UnsupportedOperationException
	at java.base/java.util.Collections$UnmodifiableCollection.add(Collections.java:1056)
	at myPackage.CollectionsUnmodifiableNavigableSetExample3.main(CollectionsUnmodifiableNavigableSetExample3.java:9)

相關用法

注：本文由純淨天空篩選整理自 Java Collections unmodifiableNavigableSet() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。