Why @Valid do not works

Question

I am taking an online course and the instructor placed two notes to validate fields in my category object. An @Notnull annotation in the name attribute and @Valid in the controller, in his video the error http response changes from 500 to 400, as it is validating the attributes. Before he put the validation back, he returned 500. Mine keeps returning 500. In other words, the annotations @Valid and @Notnull do not seem to have any effect, does anyone know why? Here is my code:

MyPom:

<?xml version="1.0" encoding="UTF-8"?>

4.0.0 org.springframework.boot spring-boot-starter-parent 2.3.1.RELEASE jar --> com.algaworks.algamoney-api algamoney-api 1.0.0-SNAPSHOT algamoney-api Demo project for Spring Boot

<properties>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>2.0.1.Final</version>
    </dependency>
    <dependency>
        <groupId>org.flywaydb</groupId>
        <artifactId>flyway-core</artifactId>
        <version>6.4.4</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

MyController

package com.example.algamoney.api.resource;

import java.net.URI;
import java.util.List;
import java.util.Optional;

import javax.servlet.http.HttpServletResponse;
import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
import org.springframework.web.util.UriBuilder;

import com.example.algamoney.api.model.Categoria;
import com.example.algamoney.api.repository.CategoriaRepository;

@RestController
@RequestMapping("/categoria")
public class CategoriaResource {
    
    @Autowired
    private CategoriaRepository categoriaRepository;
    
    @GetMapping("/listar")
    public List<Categoria> listar(){
        return categoriaRepository.findAll();
    }
    
    @PostMapping("/criar")
    public ResponseEntity<Categoria> criar(@Valid @RequestBody Categoria categoria, HttpServletResponse response) {
        Categoria categoriaSalva = categoriaRepository.save(categoria);
        URI uri = ServletUriComponentsBuilder.fromCurrentRequestUri().path("/{codigo}")
                .buildAndExpand(categoria.getCodigo()).toUri();
        response.setHeader("Location", uri.toASCIIString());
        return ResponseEntity.created(uri).body(categoriaSalva);
    }
    
    @GetMapping("/buscar/{codigo}")
    public Optional<Categoria> buscarCategoriaPorCodigo(@PathVariable Long codigo) {
        return categoriaRepository.findById(codigo);
    }

}

And MyObject

package com.example.algamoney.api.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;

@Entity
@Table(name = "categoria")
public class Categoria {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @NotNull(message = "Nome não pode ser nulo")
    private String nome;
    
    public Long getCodigo() {
        return id;
    }
    public void setCodigo(Long codigo) {
        this.id = codigo;
    }
    public String getNome() {
        return nome;
    }
    public void setNome(String nome) {
        this.nome = nome;
    }
    
}

Answer 1

please check for maven dependencies if not their add them for using @Valid in you project. you can add them from : https://mvnrepository.com/artifact https://mvnrepository.com/artifact/org.hibernate.validator/hibernate-validator https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-validation https://mvnrepository.com/artifact/javax.validation/validation-api

Answer 2

Some annotations are part of JSR 380 & some are JSR 303. so try to include below dependency that supports most of the javax validations.

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>6.1.5.Final</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
    <version>2.3.1.RELEASE</version>
</dependency>