Validation

Problem

Как проверять что данные которые приходят или содержатся в объекте, удовлетворяют неким требованиям

Solution

Validation

Dependencies

API

<dependency>
    <groupId>jakarta.validation</groupId>
    <artifactId>jakarta.validation-api</artifactId>
    <version>3.0.1</version>
</dependency>

Reference IMPL

<dependency>
    <groupId>org.hibernate.validator</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>7.0.4.Final</version>
</dependency>

Extra dependencies

<!-- EL API -->
<dependency>
    <groupId>jakarta.el</groupId>
    <artifactId>jakarta.el-api</artifactId>
    <version>4.0.0</version>
</dependency>
<!-- EL IMPL -->
<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>jakarta.el</artifactId>
    <version>4.0.2</version>
</dependency>

Examples

Domain model

public class User {
    @NotNull(message = "Name cannot be null")
    private String name;

    @AssertTrue
    private boolean working;

    @Size(min = 10, max = 200, message = "About Me must be between 10 and 200 characters")
    private String aboutMe;

    @Min(value = 18, message = "Age should not be less than 18")
    @Max(value = 150, message = "Age should not be greater than 150")
    private int age;

    @Email(message = "Email should be valid")
    private String email;

    // getters and setters
}

Using validation

public class Example1 {
    public static void main(String[] args) {
        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        Validator validator = factory.getValidator();

        User user = new User();
        user.setWorking(true);
        user.setAboutMe("Its all about me!");

        Set<ConstraintViolation<User>> violations = validator.validate(user);

        for (ConstraintViolation<User> violation : violations) {
            System.out.println(violation.getMessage());
        }
    }
}

Output

Apr 12, 2022 7:09:40 AM org.hibernate.validator.internal.util.Version <clinit>
INFO: HV000001: Hibernate Validator 7.0.4.Final
Age should not be less than 18
Name cannot be null