Spring Boot - Validations stopped working after upgrade from 2.2.5 to 2.3.0

Question

Validation starter not included in web starters anymore.

The spring-boot-starter-validation is not a transitive dependency of spring-boot-starter-web and spring-boot-starter-webflux anymore.

Add this dependency for validations work.

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

According to spring boot 2.3.1 release there is no longer contains spring-boot-starter-validation with spring starter

how to add starter validation on

maven

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

Gradle

dependencies {
  ...
  implementation 'org.springframework.boot:spring-boot-starter-validation'
}

referee the release note

https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.3-Release-Notes#validation-starter-no-longer-included-in-web-starters

If your experiencing the issue of for example: not being able to see the validation errors (default-messages) returned back to the client, this is what you could do:

Top Solution 1: Simply add devtools. This should solve the issue. After I did this, all my binding-results were returned back to the client. I recommend you to test this out first:

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
</dependency>

Solution 2:

I found out that this is due to using Spring Boot 2.3+ So if youre using Spring Boot 2.3 or higher, add this dependency in your pom.xml file as its no longer included within the 'web'-dependency itself.

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

Now its necessary to set 'include binding errors' in java/resources/application.properties to "always". Same goes for 'message' as well although I think this is optional.

server.error.include-message=always
server.error.include-binding-errors=always

Solution 3: (before I discovered solution 2 which could be helpful as well)

So I found out that this is due to having Spring boot 2.3+. But I could not find caution-messages on the new updated usage of @Valid in Spring Boot v2.3+.

So I ended up switching back to Spring boot v2.2.10 (latest version of 2.2) by adjusting the release version in the pom.xml file like so:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.10.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

This worked perfectly for me by rolling back to an older version. Although id like to update my Spring Boot version some day. (Revisit solution 1 & 2)

Actually there error was in the unit tests. The validation was working well.

For those who came here with the same issue, it's very likely that you are missing to add the following dependency to the pom.xml as Braian Silva suggested above:

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

Thanks for your help guys!