Java Collections checkedSet() Method

The checkedSet() is an inbuilt method of Java Collections class. This method is used to get a dynamically typesafe view of the specified Set.

Syntax

Following is the declaration of checkedSet() method:

Parameter

Parameter	Description	Required/Optional
s	It is the set for which a dynamically typesafe view is to be returned.	Required
type	It is the type of element that s is permitted to hold.	Required

Returns

The checkedSet() method automatically returns a dynamically typesafe view of the specified Set in the ascending order.

Exceptions

ClassCastException

Compatibility Version

Java 1.5 and above

Example 1

import java.util.*;
public class CollectionsCheckedSetExample1 {
	public static void main(String[] args) {
		TreeSet<String> set = new TreeSet<String>();
		//Insert values in the Set
		set.add("JavaTpoint");
		set.add("Hindi100");
		set.add("SSSIT");
		set.add("JavaTraining");
	      //Get type safe view of the Set        
	      System.out.println("Type safe view of the Set is: "+Collections.checkedSet(set,String.class));
	      }
}

Test it Now

Output:

Type safe view of the Set is: [Hindi100, JavaTpoint, JavaTraining, SSSIT]

Example 2

import java.util.*;
public class CollectionsCheckedSetExample2 {
	public static void main(String[] args) {
		TreeSet<Integer> set = new TreeSet<>();
		//Insert values in the Set
		set.add(1100);
		set.add(2200);
		set.add(500);
		set.add(900);
	      //Get type safe view of the Set  
		Set<Integer> TypeSafeSet;
		TypeSafeSet = Collections.checkedSet(set,Integer.class);
	      System.out.println("The view of the Set is: "+TypeSafeSet);
	      }
}

Test it Now

Output:

The view of the Set is: [500, 900, 1100, 2200]

Example 3

import java.util.*;
public class CollectionsCheckedSetExample3 {
	public static void main(String[] args) {
		Set<Integer> set = new HashSet<>();
            set = Collections.checkedSet(set, Integer.class);
            set.add(1500);
            set.add(1100);
            set.add(1800);
            System.out.println("Dynamic type safe view of Set is: "+set);
            Set set2 = set;
            set2.add("JavaTpoint");
            System.out.println(set2);
	      }
}

Test it Now

Output:

Dynamic type safe view of Set is: [1800, 1500, 1100]
Exception in thread "main" java.lang.ClassCastException: Attempt to insert class java.lang.String element into collection with element type class java.lang.Integer
	at java.base/java.util.Collections$CheckedCollection.typeCheck(Collections.java:3038)
	at java.base/java.util.Collections$CheckedCollection.add(Collections.java:3081)
	at myPackage.CollectionCheckedSetExample3.main(CollectionCheckedSetExample3.java:12)

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