It is used, when your application has third-party libraries and when you want to know about the classes and methods available.

IDE (Integrated Development Environment) E.g.

Reflection is mainly used in debugging tools, JUnit, and frameworks to inspect and change the behavior at runtime.

A distinguishing feature of Reflection API is that we can also manipulate the private data members or methods of the class. We use Reflection API provided by the above packages to modify the class and its members including fields, methods, constructors, etc. The special class “” provides the methods and properties to extract metadata using which we can inspect and modify the class behavior. In Java, the “java.lang” and “” are the two packages that provide classes for reflection. We inspect these objects and then change their behavior at runtime using reflection API. The objects can be anything like methods, interfaces, classes, etc. Thus we can use Reflection API in our programs for the purpose of modifying the object’s behavior. As a result, we can modify the behavior of this object at runtime. Then we use the Reflection API on this object. In the above representation, we can see that we have an unknown object. The “Reflection” process is depicted below. Reflection is an “Application Programming Interface” (API) provided by Java. An object can be a class, a field, or a method.” Thus a Reflection can be defined as a “technique of inspecting and modifying the runtime behavior of an unknown object at run time. Java programming language provides a feature called “Reflection” that allows us to modify the runtime behavior of a class or field or method at runtime.

In other words, it is very difficult to change the behavior of various programming components at runtime especially for unknown objects. Whether the properties and methods are anonymous or have names, they can be changed at our will during compile time.īut we cannot change these classes or methods or fields at runtime on the fly.

We are aware that in a given class we can modify its properties and methods at compile time and it is very easy to do so.

Java reflection get private field