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