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Java Collections checkedMap() Method
The checkedMap() is an inbuilt method of Java Collections class. This method is used to get a dynamically typesafe view of the specified Map. If 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 checkedMap() method:
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 checkedMap() method returns a dynamically typesafe view of the specified Map.
Exceptions
ClassCastException
Compatibility Version
Java 1.5 and above
Example 1
Output:
Type safe view of the Map is: {A=11, B=12, C=13, V=14}
Example 2
Output:
Map Element: {1=One, 2=Two, 3=Three} {1=One, 2=Two, 3=Three, Four=4}
Example 3
Output:
Map content: {Rahul=3, Amit=4, Raj=1, TutorAspire =2} Exception in thread "main" java.lang.ClassCastException: Attempt to insert class java.lang.Integer key into map with key type class java.lang.String at java.base/java.util.Collections$CheckedMap.typeCheck(Collections.java:3575) at java.base/java.util.Collections$CheckedMap.put(Collections.java:3621) at myPackage.CollectionCheckedMapExample3.main(CollectionCheckedMapExample3.java:13)
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