一、什麽是數據校驗？

　　　　　　這個比較好理解，就是用來驗證客戶輸入的數據是否合法，比如客戶登錄時，用戶名不能為空，或者不能超出指定長度等要求，這就叫做數據校驗。

　　　　　　數據校驗分為客戶端校驗和服務端校驗

　　　　　　　　客戶端校驗：js校驗

　　　　　　　　服務端校驗：springmvc使用validation校驗，struts2使用validation校驗。都有自己的一套校驗規則。

數據校驗

第一步：引入依賴

<!--數據校驗-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>4.3
 
.1.Final</version>
        </dependency>

        <!--validation api-->
        <dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>1.0.0.GA</version>
        </dependency>

第二步：配置驗證器在springmvc.xml中

<?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: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/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="demo18Validator"></context:component-scan>

    <!--視圖解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <!--配置驗證器-->
    <bean id="myValidator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
        <property name="providerClass" value="org.hibernate.validator.HibernateValidator"></property>
    </bean>

    <!--註解驅動-->
    <mvc:annotation-driven validator="myValidator"></mvc:annotation-driven>



</beans>

第三步：使用註解驅動關聯驗證器

在這裏要聲明一個用戶類

package demo18Validator.domain;

import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.format.annotation.DateTimeFormat;

import javax.validation.constraints.*;
import java.util.Date;

/**
 * Created by mycom on 2018/3/31.
 */
public class UserInfo {
    @NotEmpty(message = "用戶名不能為空")
    @Size(min = 6,max = 20,message = "用戶名必須在{min}-{max}之間")
    private String username;
    @Max(value = 150,message = "年齡最大不能超過150")
    @Min(value=18,message = "年齡做小不能低於18")
    private Integer userage;
    @NotNull(message = "出生日期不能為空")
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date birthday;
    @NotEmpty(message = "手機號碼不能為空")
    @Pattern(regexp = "^1[3|5|7|8|9]\\d{9}$",message = "手機號格式不正確")
    private String userphone;
    @NotEmpty(message = "郵箱不能為空")
    @Pattern(regexp = "^\\w+@\\w+\\.\\w+$",message = "郵箱格式不正確")
    private String email;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getUserage() {
        return userage;
    }

    public void setUserage(Integer userage) {
        this.userage = userage;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getUserphone() {
        return userphone;
    }

    public void setUserphone(String userphone) {
        this.userphone = userphone;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }


}

第四步：寫控制器類

package demo18Validator;

import demo18Validator.domain.UserInfo;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.validation.Valid;

/**
 * Created by mycom on 2018/3/31.
 */
@Controller
public class FirstController {
    @RequestMapping("/first")
    public String doFirst(@Valid UserInfo info, BindingResult br, Model model){
        //判斷br中錯誤總數是否大於0，如果大於0那麽在模型中至少有一個是驗證錯誤的
        if(br.getErrorCount()>0){
            //模型驗證失敗,獲取到那個屬性驗證失敗了
            FieldError username = br.getFieldError("username");
            FieldError userage = br.getFieldError("userage");
            FieldError userphone = br.getFieldError("userphone");
            FieldError email = br.getFieldError("email");
            FieldError birthday = br.getFieldError("birthday");
            //如果usernamemsg不為空那麽就是他驗證失敗，同理其他屬性也是
            if(username!=null){
                //驗證失敗後，獲得到失敗的信息，並把它放入model中
                String usernamemsg = username.getDefaultMessage();
                model.addAttribute("usernamemsg",usernamemsg);
            }
            if(userage!=null){
                //驗證失敗後，獲得到失敗的信息，並把它放入model中
                String useragemsg = userage.getDefaultMessage();
                model.addAttribute("useragemsg",useragemsg);
            }
            if(userphone!=null){
                //驗證失敗後，獲得到失敗的信息，並把它放入model中
                String userphonemsg = userphone.getDefaultMessage();
                model.addAttribute("userphonemsg",userphonemsg);
            }
            if(email!=null){
                //驗證失敗後，獲得到失敗的信息，並把它放入model中
                String emailmsg = email.getDefaultMessage();
                model.addAttribute("emailmsg",emailmsg);
            }
            if(birthday!=null){
                //驗證失敗後，獲得到失敗的信息，並把它放入model中
                String birthdaymsg = birthday.getDefaultMessage();
                model.addAttribute("birthdaymsg",birthdaymsg);
            }
            /*驗證失敗後，仍然會到表單頁面*/
            return "validator";
        }
        /*驗證成功之後跳到成功頁面*/
        return "success";
    }
}

頁面上

<%--
  Created by IntelliJ IDEA.
  User: mycom
  Date: 2018/3/31
  Time: 17:19
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>數據校驗</h1>
<form action="${pageContext.request.contextPath}/first" method="post">
    年齡:<input name="userage" /> <span>${useragemsg }</span><br/><br/>
    姓名:<input name="username"/><span>${usernamemsg }</span><br/><br/>
    電話:<input name="userphone"/><span>${userphonemsg }</span><br/><br/>
    出生日期:<input name="birthday"/> <span>${birthdaymsg}</span><br/><br/>
    郵箱:<input name="email"/> <span>${emailmsg}</span><br/><br/>
    <input type="submit" value="註冊"/>
</form>

</body>
</html>

成功頁面

<%--
  Created by IntelliJ IDEA.
  User: mycom
  Date: 2018/3/26
  Time: 11:57
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
登錄成功！
</body>
</html>

SpringMVC（十六）數據校驗