Question

我正在为DTO的约束验证器编写测试。它们适用于每个DTO，但使用自定义书面EmailUniqueConstraintValidator的DTO除外。发生此异常：

javax.validation.ValidationException: HV000028: Unexpected exception during isValid call.

    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateSingleConstraint(ConstraintTree.java:177)
    at org.hibernate.validator.internal.engine.constraintvalidation.SimpleConstraintTree.validateConstraints(SimpleConstraintTree.java:68)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:73)
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.doValidateConstraint(MetaConstraint.java:127)
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.validateConstraint(MetaConstraint.java:120)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateMetaConstraint(ValidatorImpl.java:533)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForSingleDefaultGroupElement(ValidatorImpl.java:496)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:465)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:430)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:380)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:169)
    at be.ambrassade.jeugdlink.model.request.UserCreateRequestTest.passwordSizeTooShortOrLongReturnsValidationError(UserCreateRequestTest.java:71)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:532)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:171)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:167)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:114)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:59)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:108)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:220)
    at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:188)
    at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:202)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:181)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.NullPointerException
    at be.ambrassade.jeugdlink.validation.EmailUniqueConstraintValidator.isValid(EmailUniqueConstraintValidator.java:33)
    at be.ambrassade.jeugdlink.validation.EmailUniqueConstraintValidator.isValid(EmailUniqueConstraintValidator.java:21)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateSingleConstraint(ConstraintTree.java:171)
    ... 50 more

这是验证者：

import be.ambrassade.jeugdlink.repo.UserRepository;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class EmailUniqueConstraintValidator implements ConstraintValidator<EmailUnique, String> {

    private UserRepository userRepository;


    public EmailUniqueConstraintValidator(UserRepository userRepository) {
        this.userRepository = userRepository;
    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        return value == null || !userRepository.existsByEmail(value);
    }
}

它没有public no arg构造函数，但是由于存储库的依赖性，添加一个没有arg构造函数也不能解决问题。

由于该自定义验证器的问题，该DTO的验证测试均无效。我该如何解决这个问题？

Answer 1

如果再次阅读堆栈跟踪信息，您会注意到异常原因是NullPointerException：

Caused by: java.lang.NullPointerException
    at be.ambrassade.jeugdlink.validation.EmailUniqueConstraintValidator.isValid(EmailUniqueConstraintValidator.java:33)

因此，解决问题的方法非常简单，请确保通过userRepository方法访问isValid字段值时不为空。

Answer 2

测试套件代码不在问题中，但根据问题描述，这应该是我最近遇到的同一个问题。

可能有点晚了，但我会发布我是如何解决这个问题的，因为它可以帮助其他人。

问题基本上是您通过调用 Validator 获得的 Hibernate 标准 Validation.buildDefaultValidatorFactory().getValidator() 实现对 Spring 的应用程序上下文一无所知，因此它无法在您的自定义约束验证器中注入依赖项。

在 Spring 应用程序中，Validator 和 ValidatorFactory 接口的实现是类 LocalValidatorFactoryBean，它可以委托给 ApplicationContext 以实例化具有依赖项的约束验证器注入。

你需要做的是

使用它们的（我认为是模拟的）依赖项实例化您的约束验证器
创建您自己的 ValidatorFactory，其中包含项目符号 1 中的所有约束验证器
从此类工厂实例化您的 Validator

这是自定义验证器工厂

public class CustomLocalValidatorFactoryBean extends LocalValidatorFactoryBean {

    private final List<ConstraintValidator<?, ?>> customConstraintValidators;

    public CustomLocalValidatorFactoryBean(List<ConstraintValidator<?, ?>> customConstraintValidators) {
        this.customConstraintValidators = customConstraintValidators;
        setProviderClass(HibernateValidator.class);
        afterPropertiesSet();
    }

    @Override
    protected void postProcessConfiguration(Configuration<?> configuration) {
        super.postProcessConfiguration(configuration);
        ConstraintValidatorFactory defaultConstraintValidatorFactory =
                configuration.getDefaultConstraintValidatorFactory();
        configuration.constraintValidatorFactory(
                new ConstraintValidatorFactory() {
                    @Override
                    public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
                        for (ConstraintValidator<?, ?> constraintValidator : customConstraintValidators) {
                            if (key.equals(constraintValidator.getClass())) //noinspection unchecked
                                return (T) constraintValidator;
                        }
                        return defaultConstraintValidatorFactory.getInstance(key);
                    }

                    @Override
                    public void releaseInstance(ConstraintValidator<?, ?> instance) {
                        defaultConstraintValidatorFactory
                                .releaseInstance(instance);
                    }
                }
        );
    }

}

然后在您的测试课程中，您只需执行以下操作：

class MyTestSuite {
    
    private final UserRepository mockUserRepository = Mockito.mock(UserRepository.class);
    private final List<ConstraintValidator<?,?>> customConstraintValidators = 
            Collections.singletonList(new EmailUniqueConstraintValidator(mockUserRepository));
    private final ValidatorFactory customValidatorFactory = 
            new CustomLocalValidatorFactoryBean(customConstraintValidators);
    private final Validator validator = customValidatorFactory.getValidator();

    @Test
    void myTestCase() {
        // mock the dependency: Mockito.when(mockUserRepository...)
        User u = new User();
        //setters omitted
        Set<ConstraintViolation<?>> violations = validator.validate(u);
        //assertions on the set of constraint violations
    }

}

希望有所帮助。您可以查看我的这篇文章了解更多详情：https://codemadeclear.com/index.php/2021/01/26/how-to-mock-dependencies-when-unit-testing-custom-validators/

验证程序单元测试由于自定义约束验证程序而失败

2 个答案: