Java Collections checkedSortedMap()用法及代碼示例

java.util.Collections類的checkedSortedMap()方法用於返回指定排序映射的動態類型安全視圖。

如果指定的映射是可序列化的，則返回的映射將是可序列化的。

由於null被認為是任何引用類型的值，因此，隻要有支持映射，返回的映射就允許插入null鍵或值。

用法:

public static  SortedMap
 checkedSortedMap(SortedMap m, Class keyType, Class valueType)

參數：此方法將以下參數作為參數

m –要為其返回動態類型安全視圖的Map
keyType –m允許持有的 key 的類型
valueType –m允許持有的值的類型

返回值：此方法返回指定映射的動態類型安全視圖。

以下示例說明了checkedSortedMap()方法

示例1:

// Java program to demonstrate 
// checkedSortedMap() method 
// for <String, String> type 
  
import java.util.*; 
  
public class GFG1 { 
    public static void main(String[] argv) 
        throws Exception 
    { 
        try { 
  
            // creating object of SortedMap<String, String> 
            SortedMap<String, String> 
                smap = new TreeMap<String, String>(); 
  
            // Adding elemnet to smap 
            smap.put("Ram", "Gopal"); 
            smap.put("Karan", "Arjun"); 
            smap.put("Karn", "Veer"); 
  
            // printing the sorted map 
            System.out.println("Sorted map:\n"
                               + smap); 
  
            // create typesafe view of the specified map 
            SortedMap<String, String> 
                tsmap = Collections 
                            .checkedSortedMap(smap, 
  
<strong>Output:</strong> 
<pre>{Karan=39, Karn=40, Ram=20}</pre> 
                                              String.class, 
                                              String.class); 
  
            // printing the typesafe view of specified sorted map 
            System.out.println("Typesafe view of sorted map:\n"
                               + tsmap); 
        } 
  
        catch (IllegalArgumentException e) { 
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

Sorted map:
{Karan=Arjun, Karn=Veer, Ram=Gopal}
Typesafe view of sorted map:
{Karan=Arjun, Karn=Veer, Ram=Gopal}

示例2:

// Java program to demonstrate 
// checkedSortedMap() method 
// for <String, Integer> type 
  
import java.util.*; 
  
public class GFG1 { 
    public static void main(String[] argv) throws Exception 
    { 
        try { 
  
            // creating object of SortedMap<String, Integer> 
            SortedMap<String, Integer> smap = new TreeMap<String, Integer>(); 
  
            // Adding elemnet to smap 
            smap.put("Ram", 20); 
            smap.put("Karan", 39); 
            smap.put("Karn", 40); 
            // printing the sorted map 
            System.out.println("Sorted map:\n"
                               + smap); 
  
            // create typesafe view of the specified map 
            SortedMap<String, Integer> 
                tsmap = Collections 
                            .checkedSortedMap(smap, 
                                              String.class, 
                                              Integer.class); 
  
            // printing the typesafe view of specified sorted map 
            System.out.println("Typesafe view of sorted map:\n"
                               + tsmap); 
        } 
        catch (IllegalArgumentException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

Sorted map:
{Karan=39, Karn=40, Ram=20}
Typesafe view of sorted map:
{Karan=39, Karn=40, Ram=20}

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 Collections checkedSortedMap() method in Java with Examples。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。