How do you implement custom error pages in Spring MVC?

Table of Contents

• Introduction
• Implementing Custom Error Pages in Spring MVC
  • 1. Using web.xml or Spring Boot application.properties
    • For Non-Spring Boot Applications (using web.xml):
    • For Spring Boot Applications:
  • 2. Using @ControllerAdvice for Global Exception Handling
    • Example: Global Exception Handling with @ControllerAdvice:
  • 3. Customizing Error Views
    • Example: Custom Error Views for Different Errors (Thymeleaf)
  • 4. Customizing Error Responses with @ResponseStatus
    • Example: Using @ResponseStatus for Custom Error Response
  • 5. Error Handling with @ResponseBody (for APIs)
    • Example: Returning JSON Error Response for REST APIs
• Conclusion

Introduction

In Spring MVC, it's essential to handle errors gracefully and provide meaningful feedback to users when something goes wrong. Rather than displaying generic server error messages, you can create custom error pages to improve the user experience. This can involve handling specific HTTP status codes (like 404 for "Not Found" or 500 for "Internal Server Error") and customizing the response to reflect the error's context.

Spring MVC provides several ways to implement custom error pages, including using configuration files, @ControllerAdvice, and defining error view templates. In this guide, we'll explore the different methods for setting up custom error pages in a Spring MVC application.

Implementing Custom Error Pages in Spring MVC

1. Using web.xml or Spring Boot application.properties

For traditional Spring MVC applications (non-Spring Boot), you can configure custom error pages using the web.xml configuration file. Alternatively, for Spring Boot applications, custom error pages can be configured using application.properties or application.yml.

For Non-Spring Boot Applications (using web.xml):

In a traditional Spring MVC application, you can define custom error pages in the web.xml configuration file, specifying which HTTP status code should trigger which error page.

In this configuration:

• Requests that result in a 404 error (Page Not Found) will be redirected to /WEB-INF/views/errors/404.jsp.
• Similarly, requests that result in a 500 error (Internal Server Error) will be redirected to /WEB-INF/views/errors/500.jsp.

For Spring Boot Applications:

In a Spring Boot application, custom error pages can be configured in the application.properties file:

You can then define a controller that handles the /error path:

In this case, you can create views such as errors/404.html or errors/500.html that will be shown based on the HTTP error code.

2. Using @ControllerAdvice for Global Exception Handling

Spring MVC provides a way to handle exceptions globally using @ControllerAdvice. This is useful for intercepting exceptions thrown by any controller method and providing custom error responses or views.

Example: Global Exception Handling with @ControllerAdvice:

In this example:

• @ExceptionHandler(ResourceNotFoundException.class) handles ResourceNotFoundException and returns a custom 404 error page (errors/404).
• A general Exception handler is defined to return a custom 500 error page.

This method allows you to handle both application-specific exceptions (like ResourceNotFoundException) and general exceptions in a centralized manner, providing consistent error pages across your application.

3. Customizing Error Views

You can also customize error views by creating specific view templates (JSP, Thymeleaf, etc.) for different HTTP error codes. When an error occurs, Spring will resolve the appropriate view based on the error code.

Example: Custom Error Views for Different Errors (Thymeleaf)

l

These HTML files can be placed under src/main/resources/templates/errors/ if you are using Thymeleaf. These views will be served to users when a 404 or 500 error occurs, providing a user-friendly experience.

4. Customizing Error Responses with @ResponseStatus

If you want to return a custom error message for a specific exception, you can annotate your exception classes with @ResponseStatus. This allows you to return a specific HTTP status code and a custom error message when an exception is thrown.

Example: Using @ResponseStatus for Custom Error Response

When this exception is thrown, Spring will automatically return a 404 status code and the message "Resource Not Found." You can further customize the response by using @ExceptionHandler to handle the exception and return custom views or error pages.

5. Error Handling with @ResponseBody (for APIs)

For RESTful APIs, it's common to handle errors using @ResponseBody to return error details in JSON format instead of rendering HTML error pages.

Example: Returning JSON Error Response for REST APIs

In this example:

• When a ResourceNotFoundException is thrown, the API will return a JSON response with an appropriate error message and a 404 NOT_FOUND status code.

Conclusion

Implementing custom error pages in Spring MVC enhances the user experience by providing clear, informative error messages instead of generic server responses. Whether you are building a traditional web application or a RESTful API, you can use Spring's various mechanisms (like web.xml, @ControllerAdvice, @ResponseStatus, and custom views) to handle errors effectively. By configuring error handling centrally and creating user-friendly error pages or JSON responses, you ensure that your application is robust, maintainable, and provides an excellent user experience.