Understanding Why InstantiationException Is Considered a Checked Exception

What is the reason InstantiationException is classified as a checked exception in Java?

The InstantiationException is a specific type of checked exception in Java that occurs when an application tries to create an instance of a class through the use of reflection, but the specified class object cannot be instantiated. This typically happens when the class does not have a valid constructor or is abstract. Since it is crucial for the program's logic to handle such errors, Java developers classify it as checked.

try {
    Class<?> clazz = Class.forName("com.example.MyClass");
    Object instance = clazz.newInstance();
} catch (InstantiationException e) {
    e.printStackTrace();  // Handle instantiation error
} catch (IllegalAccessException e) {
    e.printStackTrace();  // Handle access error
} catch (ClassNotFoundException e) {
    e.printStackTrace();  // Handle class not found error
}

Causes

• Attempting to instantiate an abstract class.
• Using a class that does not have a public no-argument constructor.
• Trying to instantiate an interface.

Solutions

• Ensure that the class being instantiated has a public constructor.
• Avoid instantiating abstract classes and interfaces directly.
• Check the class definition to confirm it is not abstract and includes a no-argument constructor.

Mistake: Assuming all classes can be instantiated using newInstance() method.

Solution: Check if the class is abstract or an interface before trying to instantiate.

Mistake: Neglecting to handle exceptions properly, leading to runtime errors.

Solution: Always include exception handling logic around reflection instantiation.