Annotation @NotEmpty doesn't check if String is null

Question

I'm trying to validate some DTOs with javax.validation, but it seems that the annotation @NotEmpty doesn't check of the parameter is null.

Here are my clases:

Person.class

public class Person {

    @NotEmpty(message = "mandatoryParametersMissing")
    private String name;

    @NotNull(message = "mandatoryParametersMissing")
    @Valid
    private Job job;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Job getJob() {
        return job;
    }

    public void setJob(Job job) {
        this.job = job;
    }

    @Override
    public String toString() {
        return "Person [name=" + name + ", job=" + job + "]";
    }

}

Job.class

public class Job {

    @NotEmpty(message = "mandatoryParametersMissing")
    private String name;

    @NotNull(message = "mandatoryParametersMissing")
    private Integer salary;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getSalary() {
        return salary;
    }

    public void setSalary(Integer salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Job [name=" + name + ", salary=" + salary + "]";
    }

}

When I try to pass the following JUnit testS I get failures:

@Test(expected = BusinessServiceException.class)
    public void testJobNameNull() {
        Person samuel = new Person();
        samuel.setName("Samuel Antequera");
        Job programmer = new Job();

        programmer.setSalary(18000);
        samuel.setJob(programmer);

        validatePerson(samuel);
    }

And here's the method that validates the DTOs:

public void validatePerson(Person in) {
    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
    Validator validator = factory.getValidator();

    Set<ConstraintViolation<Person>> violations = validator.validate(in);
    for (ConstraintViolation<Person> violation : violations) {
        throw new BusinessServiceException(violation.getMessage(), violation.getPropertyPath().toString());
    }
}

I was under the impression that @NotEmpty first checked if the parameter was null, ¿am I wrong?

PD: Here are the dependencies I use:

    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>2.0.1.Final</version>
    </dependency>

    <dependency>
        <groupId>org.hibernate.validator</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>6.1.0.Alpha5</version>
    </dependency>

    <dependency>
        <groupId>org.hibernate.validator</groupId>
        <artifactId>hibernate-validator-annotation-processor</artifactId>
        <version>6.1.0.Alpha5</version>
    </dependency>

    <dependency>
        <groupId>javax.el</groupId>
        <artifactId>javax.el-api</artifactId>
        <version>3.0.1-b06</version>
    </dependency>

    <dependency>
        <groupId>org.glassfish.web</groupId>
        <artifactId>javax.el</artifactId>
        <version>2.2.6</version>
    </dependency>

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>

It seems the problem was with the dependencies, for some reason in the class path the jar version of validation-api was wrong I simply deleted all the jars in the class path and added them again and the error disappears.

Setting the fields to an empty value and not null does trigger the validation error? — Giacomo Alzetta, Jul 17 '19 at 12:16
Nope, it still doesn't trigger the validation error. I'm starting to think that the problem is with the version of my dependencies, I added them to the post. — , Jul 17 '19 at 12:22
Uhm. It looks like the validator is not recognizing the annotations. This may be an issue with the dependencies. You should put a break point before the call to `validate` and try to debug step-by-step... hopefully at some point you will find where the validator obtains the fields and corresponding annotations and you should be able to check why the validator ignores them. Anyway: I'd start from using a stable release instead of an alpha version... — Giacomo Alzetta, Jul 17 '19 at 12:23
Thanks for the help, it seems the problem was with the dependencies, for some reason in the class path the jar version of validation-api was wrong. — , Jul 22 '19 at 09:20
I'm glad you have resolved your issue. You can answer your own question clarifying how you solved it and accept your own answer. — Giacomo Alzetta, Jul 22 '19 at 10:14

score 2 · Answer 1 · answered Jul 17 '19 at 12:03

2

@NotEmpty internally checks for minimum size of 1 and null.On documentation of @NotEmpty, it is clearly mentioned that :
"Asserts that the annotated string, collection, map or array is not {@code null} or empty."

answered Jul 17 '19 at 12:03

1

Well, when I run the test it dosn't do it. – Jul 17 '19 at 12:05
Yes, and it still fails the test – Jul 17 '19 at 12:13
Do you require it to be @Valid? – Valerij Dobler Sep 06 '21 at 11:41

score 1 · Answer 2 · edited Oct 30 '21 at 11:54

1

Check the import for @NotEmpty :

org.hibernate.validator.constraints.NotEmpty

It works for me!

I use Spring Boot 2.5.5 and Hibernate validator 6.2.0.final.

Notice that javax.validation.constraints.NotBlank not work!

edited Oct 30 '21 at 11:54

Ahmet Emre Kilinc

5,489
12
30
42

answered Oct 30 '21 at 09:50

Leon Deng

29
4

score 0 · Answer 3 · answered Jul 17 '19 at 12:40

I created a demo-project with your code fragments and it works, could you maybe check for any differences? Did you really import javax.validation.constraints.NotEmpty.

Could you also share a demo-project which shows the actual problem? Could you maybe print the toString of the person object in your test and share the output of your

See demo-project

------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running nl.martinvw.test.PersonTest
jul 17, 2019 2:38:01 PM org.hibernate.validator.internal.util.Version <clinit>
INFO: HV000001: Hibernate Validator 6.1.0.Alpha5
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.353 sec

Results :

Tests run: 2, Failures: 0, Errors: 0, Skipped: 0

Thanks for the help, it seems the problem was with the dependencies, for some reason in the class path the jar version of validation-api was wrong. — , Jul 22 '19 at 09:20

ashit07 · Answer 4 · 2019-07-18T06:01:21.287

@NotEmpty checks for @NotNull also and additionally checks the size/length of the provided object. For your above test case you will be getting 1 violation because you have not set the job name (its null) and you config says @NotEmpty(message = "mandatoryParametersMissing") private String name;

So @NotEmpty covers your @NotNull case.

I ran your above code and it worked fine. I used the below dependency

I ran your code and its working fine for me. Check the import for @NotEmpty

org.hibernate.validator.constraints.NotEmpty

I used the below dependency

   <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>6.0.13.Final</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish</groupId>
        <artifactId>javax.el</artifactId>
        <version>3.0.0</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/junit/junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

score 0 · Accepted Answer · answered Jul 22 '19 at 10:17

It seems the problem was with the dependencies, for some reason in the class path the jar version of validation-api was wrong I simply deleted all the jars in the class path and added them again and the error disappears.

Annotation @NotEmpty doesn't check if String is null

5 Answers5