Search⌘ K
AI Features
Home
Courses
The Complete Guide to Spring 6 and Spring Boot 3

Custom Error Messages

Explore how to create and configure custom error messages in Spring MVC applications. Understand how Spring Boot uses the messages.properties file to override default validation messages and how to handle type mismatch errors with specific, user-friendly notifications.

We'll cover the following...

We can specify error messages inside the annotation like this:

@NotNull(message="This is a required field.")
@Past(message="Date must be in the past.")
@Min(value=1, message="Value must be greater than or equal to 1.")
Error messages in validation annotations

These error messages override the default error messages for the constraints provided by the Hibernate validator. The Hibernate Validator is the reference implementation of the Bean Validation API. The default messages for the annotations are located in the ValidationMessages.properties file inside the hibernate-validator jar file.

Hibernate validator error messages
Hibernate validator error messages

Type mismatch errors

This type of error occurs in non-String fields when data cannot be converted into the desired datatype. For example, if a String in entered in an int field.

In such a case, Spring shows a default message, which shows why the exception was thrown. We can create a custom message in messages.properties file. The properties file is placed in the WEB-INF/resources folder and is used to externalize the error messages. When there is a constraint violation, Spring will check the messages.properties file and look for a key matching the error code. If the key is found it will display the custom error message, else use the default error message for the constraint violation. ...