Java Collections checkedNavigableMap() Method with Examples

by Online Tutorials Library July 22, 2014

Java Collections checkedNavigableMap() Method

The heckedNavigableMap() is an inbuilt method of Java Collections class. This method is used to get a dynamically typesafe view of the specified Navigable Map. If there is any attempt of insert mapping whose key or value has the wrong type, it will result in an immediate ClassCastException.

Syntax

Following is the declaration of heckedNavigableMap() method:

  public static <K,V> NavigableMap<K,V> checkedNavigableMap(NavigableMap<K,V> m, Class<K> keyType, Class<V> valueType)  

Parameter

Parameter	Description	Required/Optional
m	It is the map for which a dynamically typesafe view is to be returned.	Required
keyType	It is the type of key that map m is permitted to hold.	Required
valueType	It is the type of value that map m is permitted to hold.	Required

Returns

The checkedNavigableMap() method returns a dynamically typesafe view of the specified Navigable Map.

Exceptions

ClassCastException

Compatibility Version

Java 1.8 and above.

Example 1

  import java.util.*;  public class CollectionsCheckedNavigableMapExample1 {  public static void main(String[] args) {  NavigableMap hmap = new TreeMap<>();  //Insert values in the Map        hmap.put(“A”, 11);        hmap.put(“B”, 12);        hmap.put(“C”, 13);        hmap.put(“V”, 14);        //Create type safe view of the Map                 System.out.println(“Type safe view of the Navigable Map is: “+Collections.checkedNavigableMap(hmap,String.class,Integer.class));        }  }  ,>

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Output:

Type safe view of the Navigable Map is: {A=11, B=12, C=13, V=14}

Example 2

  import java.util.*;  public class CollectionsCheckedNavigableMapExample2 {      public static void main(String[] args) {    NavigableMap map = new TreeMap<>();          map = Collections.checkedNavigableMap(map, Integer.class, String.class);          map.put(1, “One”);          map.put(2, “Two”);          map.put(3, “Three”);          System.out.println(“Navigable Map  Element: “+map);          Map map2 = map;          //map2.put(“Four”, 4);          map2.put(4, 100);          System.out.println(“New Navigable Map  Element: “+map2);    }  }  ,>

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Output:

Navigable Map  Element: {1=One, 2=Two, 3=Three}  Exception in thread "main" java.lang.ClassCastException: Attempt to insert class java.lang.Integer value into map with value type class java.lang.String  at java.base/java.util.Collections$CheckedMap.typeCheck(Collections.java:3578)  at java.base/java.util.Collections$CheckedMap.put(Collections.java:3621)  at myPackage.CollectionCheckedNavigableMapExample2.main(CollectionCheckedNavigableMapExample2.java:13)

Example 3

  package myPackage;  import java.util.*;  public class CollectionsCheckedNavigableMapExample3 {  public static void main(String[] args) {  NavigableMap hmap = new TreeMap<>();  //Insert values in the Map        hmap.put(“A”, 11);        hmap.put(“B”, 12);        hmap.put(“C”, 13);        hmap.put(“V”, 14);        System.out.println(“Type safe view of the Navigable Map1 is: “+Collections.checkedNavigableMap(hmap,String.class,Integer.class));        NavigableMap hashmap = new TreeMap<>();        hashmap.put(11, “A”);        hashmap.put(12, “B”);        hashmap.put(11, “A”);        hashmap.put(12, “B”);        //Create type safe view of the Map                System.out.println(“Type safe view of the Navigable Map2 is: “+Collections.checkedNavigableMap(hashmap,Integer.class,String.class));              }  }  ,>,>

Test it Now

Output:

Type safe view of the Navigable Map1 is: {A=11, B=12, C=13, V=14}  Type safe view of the Navigable Map2 is: {11=A, 12=B}

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Java Collections checkedNavigableMap() Method with Examples

Java Collections checkedNavigableMap() Method

Syntax

Parameter

Returns

Exceptions

Compatibility Version

Example 1

Example 2

Example 3

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