Program/Source Code:

The source code to get the package name of a class is given below. The given program is compiled and executed successfully.

// Java program to get the package name 
// of a class

public class Main {
  public static void main(String[] args) throws ClassNotFoundException {
    Class cls1 = Class.forName("java.util.Set");
    Class cls2 = Class.forName("java.lang.String");

    System.out.println("Package names: ");
    System.out.println(cls1.getPackage());
    System.out.println(cls2.getPackage());
  }
}

Output:

Package names: 
package java.util
package java.lang

Explanation:

In the above program, we created a public class Main that contains a main() method. The main() method is the entry point for the program. In the main() method, we get the package name of specified classes using the getPackage() method and printed the result.