Java Collections checkedCollection() Method

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Description

The Java Collections checkedCollection(Collection<E>, Class<E>) method is used to get a dynamically typesafe view of the specified collection.

Declaration

Following is the declaration for java.util.Collections.checkedCollection() method.

 public static <E> Collection<E> checkedCollection(Collection<E> c,Class<E> type) 

Parameters

• c − This is the collection for which a dynamically typesafe view is to be returned.

• type − This is the type of element that c is permitted to hold.

Return Value

The method call returns a dynamically typesafe view of the specified collection.

Exception

NA

Getting a TypeSafe View of Collection of Integers Example

The following example shows the usage of Java Collection checkedCollection(Collection,Class ) method to get a typesafe view of collection of integers. We've created a List object with some integers, printed the original list. Using checkedCollection(Collection, Integer) method, we're getting a collection of Integer and then it is printed.

 package com.tutorialspoint; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.List; public class CollectionsDemo { public static void main(String[] args) { List<Integer> list = new ArrayList<>(Arrays.asList(1,2,3,4,5)); System.out.println("Initial collection value: " + list); Collection<Integer> safeList = Collections.checkedCollection(list, Integer.class); System.out.println("Typesafe View: "+safeList); } } 

Output

Let us compile and run the above program, this will produce the following result.

 Initial collection value: [1, 2, 3, 4, 5] Typesafe View: [1, 2, 3, 4, 5] 

Getting a TypeSafe View of Collection of Strings Example

The following example shows the usage of Java Collection checkedCollection(Collection,Class ) method to get a typesafe view of collection of strings. We've created a List object with some strings, printed the original list. Using checkedCollection(Collection, String) method, we're getting a collection of String and then it is printed.

 package com.tutorialspoint; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.List; public class CollectionsDemo { public static void main(String[] args) { List<String> list = new ArrayList<>(Arrays.asList("Welcome","to","Tutorialspoint")); System.out.println("Initial collection value: " + list); Collection<String> safeList = Collections.checkedCollection(list, String.class); System.out.println("Typesafe View: "+safeList); } } 

Output

Let us compile and run the above program, this will produce the following result.

 Initial collection value: [Welcome, to, Tutorialspoint] Typesafe View: [Welcome, to, Tutorialspoint]