One of the important things to focus on with REST services is the response status of an error response. The following table shows the scenarios and the error response status to use:
| Situation | Response Status |
| The request body does not meet the API specification. It does not contain enough details or contains validation errors. | ;400 BAD REQUEST |
| Authentication or authorization failure. | 401 UNAUTHORIZED |
| The user cannot perform the operation due to various factor, such as exceeding limits. | 403 FORBIDDEN |
| The resource does not exist. | 404 NOT FOUND |
| Unsupported operation, for example, trying POST on a resource where only GET is allowed. ; | 405 METHOD NOT ALLOWED |
| Error on a server. Ideally, this should not happen. The consumer ;would not be able to fix this. ; | 500 INTERNAL SERVER ERROR |
In this section, we looked at the default exception handling provided by Spring Boot and how we can customize it further to suit our needs.