spring的Validator接口用法

  spring的Validator接口用于实体bean的验证，同时把验证结果存放在Errors里。

 1。

package com.beans;

public class Person {

 private String name;
 private int age;
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
}

2。

package com.beans;

import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

public class PersonValidator implements Validator {

 public boolean supports(Class clazz) {
        return Person.class.equals(clazz);
    }
   
    public void validate(Object obj, Errors e) {
        ValidationUtils.rejectIfEmpty(e, "name", "name.empty");
        Person p = (Person) obj;
        if (p.getAge() <= 0) {
            e.rejectValue("age", "age is wrong");
        } else if (p.getAge() > 110) {
            e.rejectValue("age", "too.darn.old");
        }
    }

}

3。测试如下：

  public class ValidateTest  {
 public static void main(String[] args){
  Person photo = new Person();  
  Validator validator = new PersonValidator();  
  Errors errors = new BindException(photo, "photo");  
  boolean isSupport = validator.supports(Person.class);  
  validator.validate(photo, errors);  
  List<ObjectError> allErrors = errors.getAllErrors();  
  System.out.println(allErrors.size());
  System.out.println(allErrors.get(1).getCode());
 }
}

4。在spring mvc时候，用@Valid表示实体参数进行验证，再用@isEmpty等对实体的属性验证等等。