java - 注解@NotEmpty不检查String是否为null

Question

我正在尝试使用 javax.validation 验证一些 DTO，但似乎注释 @NotEmpty 没有检查参数是否为 null。

这是我的类(class):

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 + "]";
    }

}

工作类别

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 + "]";
    }

}

当我尝试通过以下 JUnit 测试时，我遇到了失败:

@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);
    }

这是验证 DTO 的方法:

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());
    }
}

我的印象是@NotEmpty首先检查参数是否为空，我错了吗？

PD:以下是我使用的依赖项:

    <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>

问题似乎出在依赖项上，由于某种原因，在类路径中，validation-api 的 jar 版本是错误的，我只是删除了类路径中的所有 jar，然后再次添加它们，错误就消失了。

Answer 1

@NotEmpty 内部检查最小大小为 1 和 null。在 @NotEmpty 的文档中，明确提到:
“断言带注释的字符串、集合、映射或数组不是 {@code null} 或空。”