使用Hibernate Validator进行交叉字段验证（JSR 303）
在Hibernate Validator 4.x中是否有实现（或第三方实现）的交叉字段验证？ 如果不是，那么实现交叉字段验证器的最简洁方法是什么？
例如，如何使用API来验证两个bean属性是否相等（如验证密码字段与密码验证字段匹配）。
在注释中，我希望如下所示：
public class MyBean {
@Size(min=6, max=50)
private String pass;
@Equals(property="pass")
private String passVerify;
}
每个字段约束应该由一个独特的验证器注释来处理，或者换句话说，并不建议实践将一个字段的验证注释检查与其他字段进行比较; 应在班级进行跨领域验证。 此外，JSR-303第2.2部分首选通过注释列表来表示同一类型的多个验证。 这允许每个匹配指定错误消息。
例如，验证通用表单：
@FieldMatch.List({
@FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match"),
@FieldMatch(first = "email", second = "confirmEmail", message = "The email fields must match")
})
public class UserRegistrationForm {
@NotNull
@Size(min=8, max=25)
private String password;
@NotNull
@Size(min=8, max=25)
private String confirmPassword;
@NotNull
@Email
private String email;
@NotNull
@Email
private String confirmEmail;
}
注释：
package constraints;
import constraints.impl.FieldMatchValidator;
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Target;
/**
* Validation annotation to validate that 2 fields have the same value.
* An array of fields and their matching confirmation fields can be supplied.
*
* Example, compare 1 pair of fields:
* @FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match")
*
* Example, compare more than 1 pair of fields:
* @FieldMatch.List({
* @FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match"),
* @FieldMatch(first = "email", second = "confirmEmail", message = "The email fields must match")})
*/
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch
{
String message() default "{constraints.fieldmatch}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
/**
* @return The first field
*/
String first();
/**
* @return The second field
*/
String second();
/**
* Defines several <code>@FieldMatch</code> annotations on the same element
*
* @see FieldMatch
*/
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Documented
@interface List
{
FieldMatch[] value();
}
}
验证器：
package constraints.impl;
import constraints.FieldMatch;
import org.apache.commons.beanutils.BeanUtils;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object>
{
private String firstFieldName;
private String secondFieldName;
@Override
public void initialize(final FieldMatch constraintAnnotation)
{
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
try
{
final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
return firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
}
catch (final Exception ignore)
{
// ignore
}
return true;
}
}
我建议你另一个可能的解决方案 也许不那么优雅，但更容易！
public class MyBean {
@Size(min=6, max=50)
private String pass;
private String passVerify;
@AssertTrue(message="passVerify field should be equal than pass field")
private boolean isValid() {
return this.pass.equals(this.passVerify);
}
}
isValid（）方法由验证器自动调用。
我很惊讶这不是开箱即用的。 无论如何，这是一个可能的解决方案。
我创建了一个类级别验证程序，而不是原始问题中描述的字段级别。
以下是注释代码：
package com.moa.podium.util.constraints;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = MatchesValidator.class)
@Documented
public @interface Matches {
String message() default "{com.moa.podium.util.constraints.matches}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String field();
String verifyField();
}
验证者本身：
package com.moa.podium.util.constraints;
import org.mvel2.MVEL;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public class MatchesValidator implements ConstraintValidator<Matches, Object> {
private String field;
private String verifyField;
public void initialize(Matches constraintAnnotation) {
this.field = constraintAnnotation.field();
this.verifyField = constraintAnnotation.verifyField();
}
public boolean isValid(Object value, ConstraintValidatorContext context) {
Object fieldObj = MVEL.getProperty(field, value);
Object verifyFieldObj = MVEL.getProperty(verifyField, value);
boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);
if (neitherSet) {
return true;
}
boolean matches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);
if (!matches) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("message")
.addNode(verifyField)
.addConstraintViolation();
}
return matches;
}
}
请注意，我使用MVEL来检查被验证对象的属性。 这可以用标准反射API来替代，或者如果它是您正在验证的特定类，则访问器方法本身。
然后@Matches注释可以在bean上使用，如下所示：
@Matches(field="pass", verifyField="passRepeat")
public class AccountCreateForm {
@Size(min=6, max=50)
private String pass;
private String passRepeat;
...
}
作为一个免责声明，我在过去的5分钟内写了这个，所以我可能还没有解决所有的bug。 如果出现任何问题，我会更新答案。
链接地址: http://www.djcxy.com/p/61087.html上一篇: Cross field validation with Hibernate Validator (JSR 303)