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

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, TpointTech=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)