数据校验分为前台校验和后台校验，前台校验主要是利用JavaScript来完成的，后台校验主要利用Java代码来完成的，可以使用SpringMvc和Hibernate validator来完成数据校验

1：导入Maven相关Jar包(在父pom.xml文件中)

<dependency><groupId>org.hibernate</groupId><artifactId>hibernate-validator</artifactId><version>6.0.9.Final</version>
</dependency>

2：创建Java类需要校验的数据属性上添加相应的注解

package com.doaoao.check;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.Size;public class testUser {@NotEmpty(message = "用户名不能为空")@Size(min = 5,max = 10,message = "用户名的长度为{min}-{max}之间")　　// 会将{min}替换为前面设置的min值private String username;@Min(value = 0,message = "年龄的大小不能小于{vlaue}")@Min(value = 150,message = "年龄的大小不能大于{vlaue}")private int age;public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}
}

3：修改配置文件 springmvc.xml中的内容

<!--验证器-->
<bean id="doaoaoValidator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"><property name="providerClass" value="org.hibernate.validator.HibernateValidator"/>
</bean><!--注册注解驱动-->
<mvc:annotation-driven validator="doaoaoValidator"/>

4：创建一个Controller

package com.doaoao.check;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.validation.ObjectError;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;import java.util.List;@Controller
public class UserController {@RequestMapping("/register.do")public ModelAndView register(@Validated testUser user, BindingResult br){ModelAndView m = new ModelAndView();List<ObjectError> allError = br.getAllErrors();// 当格式校验出错时执行 alllError不为空时if(allError != null && allError.size() > 0){FieldError nameError = br.getFieldError("name");FieldError ageError = br.getFieldError("age");// 当用户名输入出现问题if(nameError != null){m.addObject("nameError",nameError.getDefaultMessage());}// 当年龄输入出现问题if(ageError != null){m.addObject("ageError",ageError.getDefaultMessage());}m.setViewName("/register");return m;}m.addObject("name",user.getUsername());m.setViewName("/user");return m;}
}

5：jsp中的内容

 <form action="/register.do" method="get">用户名:<input type="text" name="username">${nameError}<br>年龄:<input type="text" name="age">${ageError}<br><input type="submit" value="提交">
</form>

# 注：hibernate validator中常用注解

...

本笔记参考自：小猴子老师教程 http://www.monkey1024.com