Question

我正在使用Hibernate Validator，并希望在错误消息中解析类别的名称。考虑这个简单的场景：

public class Category {
    private String name;
}

public class Product {
    @HazardousCategoryConstraint(message = "{haz.cat.error}")
    private Category category;
    private String name;
}

public class InventoryReport {
    @Valid
    private List<Product> products;
}


ValidationMessages.properties
haz.cat.error={name} is a product in the hazardous category list.

假设我有一个HazardousCategoryConstraint的工作实现。验证器根据受限制的名称列表检查每个类别的名称。当我调用validate（InventoryReport）时，我得到了我期望的错误数，除非它们是相同的字符串。我希望看到每个消息中的类别名称已解析。有人能指出我如何动态解决参数的例子，或者告诉我如何使用？

Answer 1

IMO，简单的解决方案是创建javax.validation.MessageInterpolator的自定义实现。将主要工作委托给Hibernate Validator的ResourceBundleMessageInterpolator并在CustomMessageInterpolator中进行必要的替换工作。

public class CustomMessageInterpolator extends org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator {

    private static final Pattern MESSAGE_PARAMETER_PATTERN = Pattern.compile( "(\\{[^\\}]+?\\})" );

    @Override
    public String interpolate(String message, Context context) {
        String resolvedMessage = super.interpolate(message, context);
        resolvedMessage = replacePropertyNameWithPropertyValues(resolvedMessage, context.getValidatedValue());
        return resolvedMessage;
    }

    private String replacePropertyNameWithPropertyValues(String resolvedMessage, Object validatedValue) {
        Matcher matcher = MESSAGE_PARAMETER_PATTERN.matcher( resolvedMessage );
        StringBuffer sb = new StringBuffer();

        while ( matcher.find() ) {
            String parameter = matcher.group( 1 );

            String propertyName = parameter.replace("{", "");
            propertyName = propertyName.replace("}", "");

            PropertyDescriptor desc = null;
            try {
                desc = new PropertyDescriptor(propertyName, validatedValue.getClass());
            } catch (IntrospectionException ignore) {
                matcher.appendReplacement( sb, parameter );
                continue;
            }

            try {
                Object propertyValue = desc.getReadMethod().invoke(validatedValue);
                matcher.appendReplacement( sb, propertyValue.toString() );
            } catch (Exception ignore) {
                matcher.appendReplacement( sb, parameter );
            }
        }
        matcher.appendTail( sb );
        return sb.toString();
    }

}

<强> @Test

public void validate() {
        Configuration<?> configuration = Validation.byDefaultProvider().configure();
        ValidatorFactory validatorFactory = configuration.messageInterpolator(new CustomMessageInterpolator()).buildValidatorFactory();
        Validator validator = validatorFactory.getValidator();

        Product p = new Product();
        Category cat = new Category();
        cat.setName("s"); //assume specified name is invalid
        p.setCategory(cat);

        Set<ConstraintViolation<Product>> violations = validator.validate(p);
        for(ConstraintViolation<Product> violation : violations) {
            System.out.println(violation.getMessage());
        }
    }

<强>输出

s is a product in the hazardous category list.

如何使用Hibernate Validator动态解析消息参数？

1 个答案: