How to access Private Field and Method Using Reflection in Java? Example Tutorial

Reflection in Java is a very powerful feature and allows you to access private methods and fields which is not possible by any other means in Java and because of this feature of reflection many code coverage tools, static analysis tools,s and Java IDE like Eclipse and Netbeans has been so helpful. In the last article, we have seen details about private keywords in Java and learned why we should always make fields and methods private in Java. There we have mentioned that private fields and methods are only accessible in the class they are declared but with reflection, you can call the private method and access private fields outside the class. In this article, we will see a simple example of accessing a private field using reflection and invoking a private method using reflection in Java.

How to Invoke Method by Name in Java Dynamically Using Reflection? Example

In Java you can invoke any method by its string name dynamically using reflection API. java.lang.reflect API provides powerful reflection mechanism which can load classes by its name even if classes are not available at compile time, Can get all methods including private and public from class and allow you to invoke any method dynamically using reflection. For those who are new to Java this sound pretty strange that at runtime you provide a method name using string and Java can run that method without any code for calling the method during compilation, but Reflection is such a powerful mechanism it allows to do a lot of stuff dynamically and if you been using IDE like Netbeans or Eclipse, a J2EE framework like Spring and Struts, these all used reflection to provide powerful configuration module and several other useful features like code assist etc.