Class getDeclaredClasses() method in Java with Examples

The getDeclaredClasses() method of java.lang.Class class is used to get the classes of this class, which are the classes that are private, public, protected or default and its members, but not the inherited ones. The method returns the classes of this class in the form of array of Class objects. 
Syntax:

public Class[] getDeclaredClasses()
               throws SecurityException

Parameter: This method does not accept any parameter.
Return Value: This method returns the classes of this class in the form of an array of Class objects. 
Exception This method throws SecurityException if a security manager is present and the security conditions are not met.
Below programs demonstrate the getDeclaredClasses() method.
Example 1:

Java

// Java program to demonstrate
// getDeclaredClasses() method

import java.util.*;

public class Test {
    public static void main(String[] args)
        throws ClassNotFoundException
    {

        // returns the Class object for this class
        Class myClass = Class.forName("Test");

        System.out.println("Class represented by myClass: "
                           + myClass.toString());

        // Get the classes of myClass
        // using getDeclaredClasses() method
        System.out.println(
            "DeclaredClasses of myClass: "
            + Arrays.toString(
                  myClass.getDeclaredClasses()));
    }
}

Output:

Class represented by myClass: class Test
DeclaredClasses of myClass: []

Example 2:

Java

// Java program to demonstrate
// getDeclaredClasses() method

import java.util.*;

class Main {

    private class Arr {
    };

    public static void main(String[] args)
        throws ClassNotFoundException
    {
        // returns the Class object for this class
        Class myClass = Class.forName("Main");

        System.out.println("Class represented by myClass: "
                           + myClass.toString());

        // Get the classes of myClass
        // using getDeclaredClasses() method
        System.out.println(
            "DeclaredClasses of myClass: "
            + Arrays.toString(
                  myClass.getDeclaredClasses()));
    }
}

Output:

Class represented by myClass: class Main
DeclaredClasses of myClass: [class Main$Arr]

Reference: https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html#getDeclaredClasses–