我正在尝试为我拥有的验证器类编写单元测试。因此，在我的UniqueEmailValidator类中，我注入了@Service组件以检查其是否存在。

@AllArgsConstructor
public class UniqueEmailValidator implements ConstraintValidator<UniqueEmail, String> {

    private final AccountService accountService;

    @Override
    public void initialize(final UniqueEmail constraintAnnotation) {
    }

    @Override
    public boolean isValid(final String email, final ConstraintValidatorContext context) {
        return !this.accountService.findByEmail(email).isPresent();
    }
}

@Documented
@Target({TYPE, FIELD, ANNOTATION_TYPE}) 
@Retention(RUNTIME)
@Constraint(validatedBy = UniqueEmailValidator.class)
public @interface UniqueEmail {

    String message() default "{com.x.x.validator.UniqueEmail.message}";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

我试图为此约束验证器编写单元测试。

@RunWith(SpringRunner.class)
@DataJpaTest
public class AccountValidatorTest {

    private static Validator validator;

    @BeforeClass
    public static void setUp() {
        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        validator = factory.getValidator();
    }

    @Autowired
    private AccountRepository accountRepository;

    @Test
    public void shouldDetectDuplicatedEmailAddress() {

        User user = new User(); 
        // Setters omit

        // accountRepository.save(user);

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

        assertEquals(1, violations.size());
    }

}

如何在Validator类中初始化AccountService？似乎没有注入，因此为null异常。这是痕迹。

javax.validation.ValidationException: HV000064: Unable to instantiate ConstraintValidator: com.x.x.validator.UniqueEmailValidator.
    at org.hibernate.validator.internal.util.privilegedactions.NewInstance.run(NewInstance.java:43)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorFactoryImpl.run(ConstraintValidatorFactoryImpl.java:43)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorFactoryImpl.getInstance(ConstraintValidatorFactoryImpl.java:28)
    at org.hibernate.validator.internal.engine.constraintvalidation.ClassBasedValidatorDescriptor.newInstance(ClassBasedValidatorDescriptor.java:65)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorManager.createAndInitializeValidator(ConstraintValidatorManager.java:184)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorManager.getInitializedValidator(ConstraintValidatorManager.java:136)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:148)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:124)
    at org.hibernate.validator.internal.engine.constraintvalidation.SimpleConstraintTree.validateConstraints(SimpleConstraintTree.java:55)
    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 com.x.x.AccountValidatorTest.shouldDetectDuplicatedEmailAddress(AccountValidatorTest.java:95)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:73)
    at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: java.lang.InstantiationException: com.x.x.validator.UniqueEmailValidator
    at java.lang.Class.newInstance(Unknown Source)
    at org.hibernate.validator.internal.util.privilegedactions.NewInstance.run(NewInstance.java:40)
    ... 50 more
Caused by: java.lang.NoSuchMethodException: com.x.x.validator.UniqueEmailValidator.<init>()
    at java.lang.Class.getConstructor0(Unknown Source)
    ... 52 more

谢谢。