Kodejava

java.lang.reflect Code Samples

• How do I invoke a method using Method class?
• How do I get field of a class object and set or get its value?
• How do I get fields of a class object?
• How do I get the methods of a class object?
• How do I determine if a class object represents an array class?
• How do I create object using Constructor object?
• How do I get constructors of a class object?
• How do I get modifiers of a class object?
• How do I get the component type of an array?
• How do I get information regarding class name?
• How do I get direct superclass and interfaces of a class?
• How do I check if a class represent a primitive type?
• How do I check if a class represent an interface type?

How do I get direct superclass and interfaces of a class?

Java reflection also dealing with inheritance concepts. You can get the direct interfaces and direct superclass of a class by using method getInterfaces() and getSuperclass() of java.lang.Class object.

• getInterfaces() will returns an array of Class objects that represent the direct super interfaces of the target Class object
• getSuperclass() will returns the Class object representing the direct super class of the target Class object or null if the target represents Object class, an interface, a primitive type, or void.

package org.kodejava.example.lang.reflect;

import javax.swing.*;
import java.util.Date;

public class GetSuperClassDemo {
    public static void main(String[] args) {
        GetSuperClassDemo.get(String.class);
        GetSuperClassDemo.get(Date.class);
        GetSuperClassDemo.get(JButton.class);
        GetSuperClassDemo.get(Timer.class);
    }

    public static void get(Class clazz) {
        //
        // Gets array of direct interface of clazz object
        //
        Class[] interfaces = clazz.getInterfaces();

        System.out.format("Direct Interfaces of %s:%n",
                clazz.getName());
        for (Class clz : interfaces) {
            System.out.println(clz.getName());
        }

        //
        // Gets direct superclass of clazz object
        //
        Class superclz = clazz.getSuperclass();
        System.out.format("Direct Superclass of %s: is %s %n",
                clazz.getName(), superclz.getName());
        System.out.println("====================================");
    }
}

Here is the result of the code snippet:

Direct Interfaces of java.lang.String:
java.io.Serializable
java.lang.Comparable
java.lang.CharSequence
Direct Superclass of java.lang.String: is java.lang.Object 
====================================
Direct Interfaces of java.util.Date:
java.io.Serializable
java.lang.Cloneable
java.lang.Comparable
Direct Superclass of java.util.Date: is java.lang.Object 
====================================
Direct Interfaces of javax.swing.JButton:
javax.accessibility.Accessible
Direct Superclass of javax.swing.JButton: is javax.swing.AbstractButton 
====================================
Direct Interfaces of javax.swing.Timer:
java.io.Serializable
Direct Superclass of javax.swing.Timer: is java.lang.Object 
====================================