How do you handle REST API errors with RestTemplate in Spring Boot?

Table of Contents

• Introduction
• Error Handling Approaches with RestTemplate
  • 1. Using Default Error Handling
    • Example:
  • 2. Using a Custom ErrorHandler
    • Implementation:
    • Usage:
  • 3. Using Interceptors for Advanced Handling
    • Implementation:
    • Usage:
• Practical Examples
  • Example 1: Handling Specific HTTP Status Codes
  • Example 2: Logging and Retrying Failed Requests
• Conclusion

Introduction

Handling errors in REST API communication is crucial for building robust Spring Boot applications. The RestTemplate class provides mechanisms to handle HTTP errors, such as invalid responses, server errors, and more. This guide explores various approaches, including default error handling, custom error handlers, and practical examples for managing REST API errors with RestTemplate.

Error Handling Approaches with RestTemplate

1. Using Default Error Handling

By default, RestTemplate throws a RestClientException or its subclass, such as HttpClientErrorException or HttpServerErrorException, for non-2xx HTTP responses.

Example:

2. Using a Custom ErrorHandler

You can create a custom ResponseErrorHandler to handle errors based on specific requirements.

Implementation:

Usage:

3. Using Interceptors for Advanced Handling

Interceptors provide another way to handle errors and log details about requests and responses.

Implementation:

Usage:

Practical Examples

Example 1: Handling Specific HTTP Status Codes

Example 2: Logging and Retrying Failed Requests

Combine an interceptor with retry logic to handle errors gracefully.

Conclusion

Handling REST API errors with RestTemplate in Spring Boot ensures robust and resilient applications. By leveraging default error handling, custom error handlers, and interceptors, you can effectively manage HTTP errors, log details, and retry failed requests. Understanding these mechanisms helps maintain smooth communication with external APIs.