Java Tutorials
Java Custom Exception (User-Defined): Use, Examples, Create, Program
Table of Contents
- Introduction
- What is Custom Exception in Java?
- Why Use Custom Exceptions?
- How to Create Custom Exception in Java?
- Java Custom Exception Example
- Types of Custom Exceptions in Java
- User-defined Exception Program in Java
Java Custom Exception FAQs
Custom exceptions are useful when you encounter application-specific error conditions that cannot be adequately represented by existing built-in exceptions. By creating custom exceptions, you can provide more informative error messages and differentiate between various exceptional situations, making your code more readable and maintainable.
To throw a custom exception in Java, you can use the throw keyword followed by the instantiation of your custom exception class with an appropriate error message or any additional data required by the constructors.
Yes, you can catch multiple custom exceptions or even mix them with standard exceptions in a single catch block by using the pipe symbol (|) introduced in Java 7.
The decision to make a custom exception checked or unchecked depends on the nature of the exception and the context in which it will be used. If the exception represents a recoverable situation, it's better to make it a checked exception (i.e., extending Exception). If the exception indicates an unrecoverable error, consider making it an unchecked exception (i.e., extending RuntimeException).
While custom exceptions can improve code readability and maintainability, it's essential to use them judiciously. Only create custom exceptions when they genuinely represent distinct error scenarios that require different handling. Too many custom exceptions can complicate the codebase, so try to strike a balance between granularity and simplicity.
No, custom exceptions should be inherited from the Exception class (for checked exceptions) or the RuntimeException class (for unchecked exceptions). Both Exception and RuntimeException classes are subclasses of the Throwable class.
