When working with Java, we might have come across two different ways to create objects. One is the traditional, direct way, and the other uses reflection. But have we ever wondered why reflection is considered slower? Let’s break it down with examples and see what’s happening under the hood.
Direct Object Creation
The most common way to create an object in Java is by using the new keyword:
Car car = new Car();This approach is straightforward. The Java compiler knows exactly which class to instantiate, so it can directly allocate memory and initialize the object. This process is fast and efficient.
Object Creation Using Reflection
Reflection allows we to create objects dynamically at runtime, even if we don’t know the class at compile time:
Object cN = ClassLoader.loadClass("com.murtuzarahman.Car");Here, Java has to do extra work:
- It searches for the class by name.
- It checks if the class exists in the specified package.
- It loads the class into memory if it’s not already loaded.
If the class or package doesn’t exist, we’ll get a ClassNotFoundException. This dynamic lookup and loading process is what makes reflection slower compared to direct instantiation.
Why is Reflection Slower?
Reflection is slower because it is checking all files and directorys, while direct instantiation is straightforward and efficient. Use reflection only when we need to create objects dynamically.