java - 如何在自定义验证注释上插入 ConstraintValidator 消息

Question

我已经阅读了一些关于如何使用 Hibernate 的 ConstrainValidator 的问答和指南(例如 Hibernate Documentation )，但没有一个明确提及如何在 a 的特定位置中插入值。创建您自己的自定义验证注释时出现验证错误消息。

例如，如果我有一条如下所示的验证错误消息:

foo.bar.error=This value '{myValue}' is wrong.

如果验证失败，我希望获得以下消息:

The value 'some wrong value' is wrong.

验证将像这样使用:

public class SomeClass {

    @CustomAnnotation(message="{foo.bar.error}")
    public MyObject myObject;

    ...

}

public class MyObject {
    private String myValue;

    ...
}

Answer 1

我找到了一种无需太多模糊即可插入消息的方法。

首先像以前一样设置您的 ValidationMessages.properties (或存储验证消息的任何位置):

foo.bar.error=This value '{wrongValue}' is wrong.

像平常一样创建注释:

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

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

@Documented
@Constraint(validatedBy = CustomValueValidator.class)
@Target(FIELD)
@Retention(RUNTIME)
public @interface CustomAnnotation {    
    String message() default "{foo.bar.error}";

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

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

像这样实现约束 validator :

import org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorContextImpl;

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

public class CustomValueValidator 
        implements ConstraintValidator<CustomAnnotation, MyObject> {

    @Override
    public void initialize(final CustomAnnotation constraintAnnotation) {
        // Extract any value you would need from the annotation
    }

    @Override
    public boolean isValid(final MyObject myObject, 
                           final ConstraintValidatorContext context) {
        boolean valid;

        // Add your validations over the 'myObject' object

        if (!valid) {
            ((ConstraintValidatorContextImpl) context)
                    .addMessageParameter("wrongValue", myObject.getMyValue());
        }

        return valid;
    }
}

现在剩下的就是使用注释:

public class SomeClass {

    // I'm using the default message. You could override it as a parameter
    @CustomAnnotation
    public MyObject anotherObject;

    ...

}