Reflection API

Reflection API:-
- Working with classes and interfaces of java.lang.Reflect.

-  Java lang is default package of java. But its sub packages are not default packages.

c language is set of functions. (.h files).

c++ is set of classes and functions (.h files).

Java is set of classes and interfaces (packages).

- Reflection means mirror image to perform a mirror image operations on a given Java class or interface to gather detail of them like member variables, names, super class names and etc., we use reflection API.

- Reflection API can develop

1. class Browsers
2. Debuggers
3. GUI Builders 

These are part of IDE softwares.

Class Browser:-

- Using Class Browser Software we can gather internal details about given class.

Debugging:-

- Debugging is a process of fixing the problem by tracing flow of execution. while developing this debugger software developers will use Reflection API.

GUI Builder:-

- A GUI Builder is a application which allows the programmer to develop GUI screens based on drag and drop operations.  In this application to show the properties of selected components Reflection API support is required.

- IDE softwares contain Class Browsers, Debuggers and GUI Builders. So Reflection API is very useful to develop IDE softwares in java.

Editors for Java

1. Traditional Editors

    - Notepad, wordpad,ms-dos editor for windows

    - ui , pico ,ed for linux/unix

 2. Third Party Editors/Modern Editors

    - Ecllipse developed by Ecllipse Organization

    - RAD developed by IBM

    - NetBeans developed by Jet Brains + Sun Microsystems

    - JBuilder developed by Borland

- code to get list of interfaces implemented by given class

1. Class c = Class.forName("Test");
2. Class inter[]=c.getInterfaces();
3. for(int i=0; i<inter.length;++i)

{

String iname = inter[i].getName();

System.out.println("\t"+ iname);

}

inter[]

|--------- |

|class obj | 0

|--------- |

|class obj | 1

|--------- |

|class obj | 2

|--------- |

Class Test implements x,y,z

{

// variables

// methods

}

- Reflection API programs can act as mirror devices for a given java class/interface.