SpringMVC之编程式校验

1.编程式效验需要实现Validator接口，针对模型类进行校验
2.jar包

3.项目测试结构

4.StudentModel.java（模型类）

 package com.wt.entity;

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

 }

5.StudentValidator.java（校验器）

 package com.wt.entity;

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

 public class StudentValidator implements Validator{
     //验证是否支持效验的StudentModel对象，匹配则执行效验
     @Override
     public boolean supports(Class<?> clazz) {

         return StudentModel.class.equals(clazz);
     }
     //效验数据的方法，object为效验的对象，Errors为效验的错误信息
     @Override
     public void validate(Object obj, Errors errors) {
         //效验name和pwd属性为空时加入错误信息
         ValidationUtils.rejectIfEmpty(errors, "name", null,"姓名不能为空");
         ValidationUtils.rejectIfEmpty(errors, "pwd", null,"密码不能为空");
         if(errors.hasErrors()){
             //上面发现错误,直接返回,下面也无需效验
             return;
         }
         //针对属性的规则进行具体效验
         StudentModel stu=(StudentModel) obj;
         if(stu.getName().length()<5||stu.getName().length()>10){
             errors.rejectValue("name", null, "姓名长度错误，应在5~10间");
         }
         if(stu.getPwd().length()<8||stu.getPwd().length()>15){
             errors.rejectValue("pwd", null,"密码长度错误，应在8~15之间");
         }
         if(stu.getAge()<=0||stu.getAge()>100){
             errors.rejectValue("age", null, "年龄错误，应在1~100之间");
         }
     }

 }

6.ValidController.java(控制器)

 package com.wt.entity;

 import org.springframework.stereotype.Controller;
 import org.springframework.validation.Errors;
 import org.springframework.web.bind.annotation.RequestMapping;

 @Controller//定义控制器
 public class ValidController {
     //声明效验器
     StudentValidator studentValidator=new StudentValidator();
     @RequestMapping(value="validstu.html")//访问路径
     public String validStudent(StudentModel model,Errors errors){
         studentValidator.validate(model, errors);//效验对象
         if(errors.hasErrors()){//发现错误，forword到错误页面
             return "Error";
         }
         return "result";//成功

     }
 }

7.springmvc-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:mvc="http://www.springframework.org/schema/mvc"
     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.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd
         http://www.springframework.org/schema/mvc
         http://www.springframework.org/schema/mvc/spring-mvc.xsd">
         <!-- 注解扫描 -->
     <context:component-scan base-package="com.wt.entity"/>

     <!-- 完成视图的对应 -->
     <!-- 对转向页面的路径解析。prefix：前缀， suffix：后缀 -->
     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" >
         <property name="prefix" value="/WEB-INF/jsp/example1/"/>
         <property name="suffix" value=".jsp"/>
     </bean>

 </beans>

8.web.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
   <display-name>SpringMVC</display-name>
   <servlet>
     <servlet-name>article6</servlet-name>
     <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
     <init-param>
       <param-name>contextConfigLocation</param-name>
       <param-value>classpath:springmvc-servlet.xml</param-value>
     </init-param>
   </servlet>
   <servlet-mapping>
     <servlet-name>article6</servlet-name>
     <url-pattern>/url/*</url-pattern>
   </servlet-mapping>
 </web-app>

9.Errors.jsp(头部导入form标签)

 <%@ page language="java" contentType="text/html; charset=UTF-8"
     pageEncoding="UTF-8"%>
     <%@taglib prefix="sf" uri="http://www.springframework.org/tags/form" %>
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Insert title here</title>
 </head>
 <body>
 <sf:form commandName="studentModel">
     显示所有错误消息
     <br>
     <sf:errors path="*"/>
     <br>
     <br>
     显示属性为age的错误信息
     <br>
     <sf:errors path="age"></sf:errors>
 </sf:form>
 </body>
 </html>

10.result.jsp

 <%@ page language="java" contentType="text/html; charset=UTF-8"
     pageEncoding="UTF-8"%>
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Insert title here</title>
 </head>
 <body>
 效验成功
 </body>
 </html>

11.测试结果