StringMVC 中如何做数据校验

步骤一：引入四个jar包

步骤二：注册类型转换器

 <context:component-scan base-package="cn.happy.controller"></context:component-scan>
       
       <!-- 配置验证器 -->
       <bean id="myvalidator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
           <property name="providerClass" value="org.hibernate.validator.HibernateValidator"></property>
       </bean> 
       
       <mvc:annotation-driven validator="myvalidator"/>

步骤三：为实体类进行注解约束

package cn.happy.entity;

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;

import org.hibernate.validator.constraints.NotEmpty;
/**
 * @Min最小值
 * @Max最大值
 * @NotEmpty 不允许为空
 * @Pattern 使用正则校验
 * @Size 长度
 */
public class UserInfo {
     //必须是0到100之间
     
    @Min(value=0,message="成绩最小值为{value}")
    @Max(value=100,message="成绩最大值为{value}")
    @NotEmpty(message="成绩不允许为空")  
    private Integer score;
    
   //手机号码必须不能为空,必须是以1 开头 第二位3,4,5,6,7,8,9   最后9位随意
    @NotEmpty(message="手机号码不允许为空")  
    @Pattern(regexp="^1[3,4,5,6,7,8,9]\\d{9}$",message="手机号码不正确")
  private String phone;
    
    //不能为空
    //必须是6个字符以上
     @NotEmpty(message="用户名不能为空") 
    @Size(min=6,message="名称至少6个字符")
  private String name;
  
    public Integer getScore() {
        return score;
    }
    public void setScore(Integer score) {
        this.score = score;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
  
  
}

步骤四：编写Handler控制器

package cn.happy.controller;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import cn.happy.entity.UserInfo;

@Controller
public class FirstController {
    @RequestMapping("/first.do")
    public ModelAndView doFirst(@Valid UserInfo info,BindingResult br){
        ModelAndView mv=new ModelAndView();
        mv.setViewName("/WELCOME.jsp");
        //记录到底是哪个字段验证失败了
        //有一个可以侦测到验证错误总数的方法
        int errorCount = br.getErrorCount();
        if (errorCount>0) {
            //证明模型验证失败
            FieldError score = br.getFieldError("score");
            FieldError name = br.getFieldError("name");
            FieldError phone = br.getFieldError("phone");
            if (score!=null) {
                mv.addObject("scoremsg",score.getDefaultMessage());
            }
            
            if (name!=null) {
                mv.addObject("namemsg",name.getDefaultMessage());
            }
            
            if (phone!=null) {
                mv.addObject("phonemsg",phone.getDefaultMessage());
            }
            mv.setViewName("/index.jsp");
        }
        
        //高中  英文版的吻别
        return mv ;
    }
}