我需要帮助。我是jsp,MVC的初学者。我想用Spring3MVC中的自定义验证器来验证表单输入。
我的验证器类
package validators;
import models.UserModel;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;
@Component
public class UserValidator implements Validator {
@Override
public boolean supports(Class clazz) {
return UserModel.class.isAssignableFrom(clazz);
}
@Override
public void validate(Object target, Errors errors) {
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "firstname", "Enter firstname.");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "surname", "Enter surname.");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "login", "Enter login.");
}
}
控制器类
package controllers;
import java.util.ArrayList;
import models.UserModel;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import validators.UserValidator;
import database.UserDB;
@Controller
public class UserController {
@RequestMapping(value="pouzivatel/new", method=RequestMethod.POST)
public ModelAndView newUser(@ModelAttribute UserModel user, BindingResult result){
UserValidator validator = new UserValidator();
validator.validate(user, result);
if(result.hasErrors()){
return new ModelAndView("/user/new","command",user);
}
...
}
面向用户的模型
package models;
public class UserModel {
private String firstname="";
private String surname="";
public String getFirstname() {
return firstname;
}
public String getSurname() {
return surname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public void setSurname(String surname) {
this.surname = surname;
}
}
JSP new.jsp,它在目录/web-inf/user中(它只是形式)
<form:form method="post" action="new.html">
<fieldset>
<table>
<tr>
<td>
<form:label path="firstname">FirstName</form:label>
</td>
<td>
<form:input path="firstname" />
<form:errors path="firstname" />
</td>
</tr>
<tr>
<td>
<form:label path="surname">Surname</form:label>
</td>
<td>
<form:input path="surname" />
<form:errors path="surname" />
</td>
</tr>
</table>
</fieldset>
<div>
<button type="submit" id="btOk">Ok</button>
</div>
</form:form>
调度程序servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="controllers" />
<context:component-scan base-package="validators" />
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>
问题是视图中显示验证消息。验证成功,变量返回(BindingResult)错误。控制器返回以下部分代码
if(result.hasErrors()){
return new ModelAndView("/user/new","command",user);
另一种方法是使用Annotation validation (我更喜欢自定义验证器),但为什么当输入字段为空时,我在视图中看不到验证消息。
你能给我举个正确的例子吗?
感谢您的回复。
发布于 2010-10-27 20:14:34
这是由于视图和控制器中的默认模型属性名称不匹配造成的:
当您编写不带modelAttribute
(或commandName
)属性的<form:form>
时,它将使用缺省模型属性名称command
.
<form:form>
,它假定此属性的名称是大写缩写的类名,即也就是说,由验证器产生的错误消息被绑定到名为userModel
的模型属性,而您的视图试图显示模型属性command
的错误。
您需要在视图(<form:form modelAttribute = "userModel" ...>
)或控制器(@ModelAttribute("command")
)中显式设置模型属性名称。
https://stackoverflow.com/questions/4031266
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