Collections checkedSet() method in Java with Examples

The checkedSet() method of java.util.Collections class is used to return a dynamically typesafe view of the specified set.
The returned set will be serializable if the specified set is serializable.
Since null is considered to be a value of any reference type, the returned set permits insertion of null elements whenever the backing set does.
Syntax:

public static  Set checkedSet(Set s, Class type)

Parameters: This method takes the following argument as a parameter 

• s: the set for which a dynamically typesafe view is to be returned
• type: the type of element that s is permitted to hold

Return Value: This method returns a dynamically typesafe view of the specified set.
Below are the examples to illustrate the checkedSet() method
Example 1:

Java

// Java program to demonstrate
// checkedSet() method
// for String value

import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
        try {

            // creating object of Set<String>
            Set<String> hset = new TreeSet<String>();

            // Adding element to hmap
            hset.add("Ram");
            hset.add("Gopal");
            hset.add("Verma");

            // print the set
            System.out.println("Set: " + hset);

            // create typesafe view of the specified set
            Set<String>
                tsset = Collections
                            .checkedSet(hset, String.class);

            // printing the typesafe view of specified list
            System.out.println("Typesafe view of Set: "
                               + tsset);
        }
        catch (IllegalArgumentException e) {

            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

Set: [Gopal, Ram, Verma]
Typesafe view of Set: [Gopal, Ram, Verma]

Example 2:

Java

// Java program to demonstrate
// checkedSet() method
// for Integer value

import java.util.*;

public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {

            // creating object of Set<Integer>
            Set<Integer> hset = new TreeSet<Integer>();

            // Adding element to hset
            hset.add(20);
            hset.add(30);
            hset.add(40);

            // print the set
            System.out.println("Set: " + hset);

            // create typesafe view of the specified set
            Set<Integer>
                tsset = Collections
                            .checkedSet(hset, Integer.class);

            // printing the typesafe view of specified list
            System.out.println("Typesafe view of Set: " + tsset);
        }
        catch (IllegalArgumentException e) {

            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

Set: [20, 30, 40]
Typesafe view of Set: [20, 30, 40]