How to Handle Exceptions in Spring Boot Filters ?

Rakesh singhania
3 min readOct 2, 2023
Photo by Elisa Ventur on Unsplash

Exception handling is a critical aspect of developing robust applications. In Spring, when working with filters, it’s essential to know how to effectively handle exceptions that may occur within the doFilter() method. In this article, we will explore best practices for managing exceptions in this context.

Using the Global Exception Handler:

  • Whenever an exception occurs in your application, Spring will look for the most specific @ExceptionHandler method in your global handler. If none match, it will use the generic Exception.class handler.
  • You can throw exceptions in your controllers or services, and the global handler will catch them.

Unfortunately The global exception handler in Spring Boot will not work for the dofilter() method in a Spring Boot filter because the dofilter() method is executed before the Spring Boot application context has been initialized.

Understanding the doFilter() Method

The doFilter() method is a key component of the Servlet Filter interface. It allows us to perform operations before and after a request is processed. However, exceptions can occur during the execution of this method, which need to be handled gracefully.

Identifying Potential Exceptions

Before diving into exception handling, it’s crucial to identify the potential points of failure within the doFilter() method. This can include database connectivity issues, external service failures, or any custom exceptions specific to your application.

Creating Custom Exceptions

To effectively handle exceptions, consider creating custom exception classes that extend the appropriate exception types. This allows for better organization and specific handling of different types of exceptions that may arise.

public class MyCustomException extends RuntimeException{
public MyCustomException(String message) {
super(message);
}
}

Implementing Try-Catch Blocks

Encapsulating the code within the doFilter() method in a try-catch block is a fundamental…

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Rakesh singhania

As a student of technology, each day I take a single step forward on the path of learning.