Exception Handling in Java: Try-Catch, Finally, and Custom Exceptions
In this article, we will explore exception handling in Java, a mechanism that allows you to handle runtime errors, preventing your program from crashing. Exception handling is essential for writing robust and fault-tolerant code. We’ll cover key concepts such as try-catch blocks, finally blocks, and how to define and handle custom exceptions.
1. What Are Exceptions?
An exception in Java is an event that disrupts the normal flow of the program’s execution. Exceptions can occur for various reasons, such as invalid user input, missing files, network failures, or division by zero. When an exception occurs, it is represented by an object of a subclass of the Throwable
class.
There are two types of exceptions in Java:
- Checked exceptions: Exceptions that the compiler forces you to handle (e.g.,
IOException
,SQLException
). - Unchecked exceptions: Exceptions that occur during runtime and are not required to be caught or declared (e.g.,
NullPointerException
,ArithmeticException
).
2. Try-Catch Block
A try-catch block is used to handle exceptions. Code that might throw an exception is placed inside the try
block. If an exception occurs, it is caught by the catch
block, where you can handle it appropriately.
Basic Syntax:
try {
// Code that might throw an exception
}…