Hi everyone, In this article we will discuss about the reflection in Java with some examples. The reflection in Java is briefly explained in the article.
Reflections in Java with examples
Table of contents:
- Introduction
- Key uses of reflection in Java
- Why we used it in Java
- How to create a reflection in Java
- Advantages of reflection in Java
- Disadvantages of reflection in Java
- Types of reflection in Java
Introduction
The reflection allows programs to inspect, manipulate classes, methods,fields,and construction at running time.
It provides the ability to analyze and modify the behavior of objects and classes dynamically without needing to know the specifics at compile time.
Key uses of reflection in Java
Here are the key uses of reflection in Java,
1. Inspecting Class Metadata
– Reflection allows you to inspect the structure of a class at runtime, including its methods, fields, constructors, and annotations.
2. Accessing Private Fields and Methods
– Reflection lets you access private fields and methods of a class, which are normally not accessible from outside the class.
3. Dynamically Invoking Methods
– Reflection enables you to invoke methods on a class dynamically at runtime, even if you don’t know the method names or parameters in advance.
4. Creating Objects Dynamically
– Reflection allows for the dynamic creation of objects at runtime using the `Constructor` class, even when the class type is not known at compile time.
5. Working with Annotations
– Reflection is used to read and process annotations at runtime, which is common in frameworks for tasks like dependency injection or object-relational mapping.
How to create a reflection in Java
- Get the class
- Get the information
- Create a objects
- Use methods
- Modify the values
Get the class
Use the .getClass() to obtain the class object that represents the class you want to inspect.
Java Class<?> ClassName=object.getclass();
Get the information
Use the methods to get information about the class members.
Create a objects
Use “newInstance()” to create an objects of the class dynamically
Use methods
Use the invoke() method to invoke methods on an object dynamically
Modify the values
Use the get() and set() methods to modify or read the values in the field.
Advantages of reflection in Java
1. Dynamic Behavior at Runtime
2. Access to Private Members
3. Framework Development
4. Runtime Object Creation
5. Working with Annotations
Disadvantages of reflection in Java
1. Performance Overhead
2. Security Risks
3. Complexity and Maintainability
4. Increased Memory Usage
5. Lack of Compile-Time Checking
Types of reflection in Java
In the reflection in Java there are two types are here
These are the following types…
- Class reflection
- Object reflection
Class reflection
Class Reflection involves using the Class object to inspect and interact with the metadata of a class itself, such as its methods, fields, constructors, annotations, etc. It allows you to examine the structure of a class at runtime.
Object reflection
Object Reflection deals with working directly with instances of a class. It involves using reflection to access or modify the fields , methods , and constructors of an object at runtime. This type of reflection allows you to manipulate the internal state of objects dynamically.