javax.validation.ValidationException：HV000064：无法实例化 ConstraintValidator

Question

我按照这篇博客文章尝试实现一个自定义验证器来验证复合主键约束，但它失败了：

javax.validation.ValidationException: HV000064: Unable to instantiate ConstraintValidator: com.directory.domain.model.validators.StorePoolValidator.
    at com.directory.domain.repositories.StorePoolRepositoryTest.shouldReturnPoolByStore(StorePoolRepositoryTest.java:30)
Caused by: java.lang.NoSuchMethodException: com.directory.domain.model.validators.StorePoolValidator.<init>()
    at com.directory.domain.repositories.StorePoolRepositoryTest.shouldReturnPoolByStore(StorePoolRepositoryTest.java:30)

下面是验证器的注解接口的代码：

javax.validation.ValidationException: HV000064: Unable to instantiate ConstraintValidator: com.directory.domain.model.validators.StorePoolValidator.
    at com.directory.domain.repositories.StorePoolRepositoryTest.shouldReturnPoolByStore(StorePoolRepositoryTest.java:30)
Caused by: java.lang.NoSuchMethodException: com.directory.domain.model.validators.StorePoolValidator.<init>()
    at com.directory.domain.repositories.StorePoolRepositoryTest.shouldReturnPoolByStore(StorePoolRepositoryTest.java:30)

这是验证器类：

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Retention(RUNTIME)
@Target({FIELD})
@Constraint(validatedBy = StorePoolValidator.class)
public @interface UniqueStorePoolConstraint {
    String message() default "Store pool validation failed";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
}

这是实体类：

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.List;

public class StorePoolValidator implements ConstraintValidator<UniqueStorePoolConstraint, StorePoolId> {

    private StorePoolRepository storePoolRepository;

    public StorePoolValidator(StorePoolRepository storePoolRepository) {
        this.storePoolRepository = storePoolRepository;
    }

    @Override
    public void initialize(UniqueStorePoolConstraint constraintAnnotation) {

    }

    @Override
    public boolean isValid(StorePoolId id, ConstraintValidatorContext context) {
        final List<StorePool> storePools = storePoolRepository.findAllByStoreNumber(id.getThirdNumber());

        return storePools.isEmpty();
    }
}

及其主键类：

@Entity
@Getter
@Setter
@Builder
@AllArgsConstructor
@Table(name = "STORE_POOLS")
public class StorePool implements Serializable {

    public StorePool() {
    }

    @EmbeddedId
    @UniqueStorePoolConstraint
    private StorePoolId id;
}

我尝试运行以下测试：

import javax.persistence.Column;
import javax.persistence.Embeddable;
import javax.validation.constraints.NotNull;
import java.io.Serializable;

@Getter
@Setter
@Builder
@ToString
@Embeddable
@EqualsAndHashCode
@AllArgsConstructor
@NoArgsConstructor(access = AccessLevel.PROTECTED)
public class StorePoolId implements Serializable {

    @Column(name = "pool", nullable = false)
    @NotNull
    private Integer pool;

    @Column(name = "third_number", nullable = false)
    @NotNull
    private Integer thirdNumber;
}

我缺少什么？谢谢。

Answer 1

很抱歉在讨论中迟到了。

首先创建一个ContextProvider，它是您需要的bean的提供者。

@Component
public class ContextProvider implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ContextProvider.applicationContext = applicationContext;
    }

    public static Object getBean(Class cls) {
        return ContextProvider.applicationContext.getBean(cls);
    }

}

现在你可以这样获取 bean：

ContextProvider.getBean(StorePoolRepository.class);

这解决了 NPE，您可以使用任何组件进行验证。

在你的例子中StorePoolValidator，

@Service
public class StorePoolValidator implements ConstraintValidator<UniqueStorePoolConstraint, StorePoolId> {

    private StorePoolRepository storePoolRepository;

    @Override
    public void initialize(UniqueStorePoolConstraint constraintAnnotation) {
         this.storePoolRepository = (StorePoolRepository) ContextProvider.getBean(StorePoolRepository.class) 
    }

    @Override
    public boolean isValid(StorePoolId id, ConstraintValidatorContext context) {
        final List<StorePool> storePools = storePoolRepository.findAllByStoreNumber(id.getThirdNumber());

        return storePools.isEmpty();
    }
}

就是这样。