如何使用Hibernate验证器动态解析消息参数?
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16-10-2019 - |
题
我正在使用Hibernate验证器,并希望在错误消息中解析该类别的名称。考虑这种简单的情况:
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.
假设我有危害categoryConstraint的工作实施。验证器根据受限名称列表检查每个类别的名称。当我调用validation(intectoryReport)时,我会得到我期望的错误数,除了它们是同一字符串。我想查看该类别的名称已解决到每个消息中。有人可以指出我如何动态解析参数或向我展示如何解决的示例?
解决方案
IMO,简单的解决方案是创建自定义实现 javax.validation.MessageInterpolator
. 。将主要工作委派给Hibernate Validator的 ResourceBundleMessageInterpolator
并进行所需的替换工作 CustomMessageInterpolator
.
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();
}
}
@测试
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());
}
}
输出
s is a product in the hazardous category list.
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