[Spring MVC] - Annotation验证

使用Spring MVC的Annotation验证可以直接对view model的简单数据验证，注意，这里是简单的，如果model的数据验证需要有一些比较复杂的业务逻辑性在里头，只是使用annotation做验证是比较难的。

以下是使用Spring MVC自带的annotation验证，加上自定义的一个@Tel的annotation验证例子，此例子具有：

1、支持多语言（国际化）

2、对默认数据先进行转化，比如int、date类型如果传入空值时，会抛异常，默认给定值

---

先看配置：

1、web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <display-name>Test Spring MVC - 1</display-name>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring.xml</param-value>
    </context-param>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value></param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

这里没什么好说的，只是把spring.xml配置加入到contextConfigLocation中

2、spring.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:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!--注解说明 -->
    <context:annotation-config />

    <!-- 默认的注解映射的支持 -->
    <mvc:annotation-driven validator="validator" conversion-service="conversionService" />

    <!-- 把标记了@Controller注解的类转换为bean -->
    <context:component-scan base-package="com.my" />

    <!-- 视图解释类 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/><!--可为空,方便实现自已的依据扩展名来选择视图解释类的逻辑  -->
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
    </bean>

    <!-- 资源文件：messages.properties -->
    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basenames">
            <list>
                <value>messages</value>
            </list>
        </property>
    </bean>
    <!-- 验证器 -->
    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
        <property name="validationMessageSource" ref="messageSource"/>
    </bean>

    <!-- 自定义数据类型转换器 -->
    <bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <list>
                <bean class="com.my.controller.converter.IntConverter" />
                <bean class="com.my.controller.converter.DateConverter" />
            </list>
        </property>
    </bean>

</beans>

在<mvc:annotation-driven/>中加入conversion-service，然后在conversion-service中加入系统默认的转换器，如上有IntConverter和DateConverter，当然，也可以是自定的别的类型，这是全局的。

在validator验证器中加入了支持多语言的properties，当然，spring的多语言是基于http header的accept-language。

3、Controller

package com.my.controller;

import java.util.List;

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.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.my.controller.bean.User4;

@Controller
@RequestMapping(value="av")
public class TestAnnotationValidController {

    @RequestMapping
    public ModelAndView index() {
        ModelAndView view = new ModelAndView("/TestAnnotationValid/index", "user4", new User4());
        return view;
    }

    @RequestMapping(value="/add", method=RequestMethod.POST)
    public ModelAndView add(@ModelAttribute @Valid User4 user, BindingResult result) {
        ModelAndView view = new ModelAndView("/TestAnnotationValid/index");
        view.addObject("user4", user);

        if(result.hasErrors()) {
            List<FieldError> errors = result.getFieldErrors();
            for(FieldError err : errors) {
                System.out.println("ObjectName:" + err.getObjectName() + "\tFieldName:" + err.getField()
                        + "\tFieldValue:" + err.getRejectedValue() + "\tMessage:" + err.getDefaultMessage() + "\tCode:");
            }
        }

        return view;
    }

}

这是一个简单的controller，在add中，有一个@Valid的annotation，这是必需的，不加这个，annotation验证将不起作用

4、User4.java model实体类

package com.my.controller.bean;

import java.util.Date;

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

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.NotBlank;

public class User4 {

    private long id;

    @NotBlank(message="{valid.name}")
    private String name;

    @Length(min=4, max=20, message="{valid.password}")
    private String password;

    @NotBlank(message="{valid.required}")
    @Email(message="{valid.email}")
    private String email;

    @NotNull(message="{valid.required}")
    private boolean married;

    @Min(value=18, message="{valid.ageMin}")
    @Max(value=100, message="{valid.ageMax}")
    private int age;

    @NotNull(message="{valid.required}")
    @Past(message="{valid.birthday}")
    private Date birthday;

    @Pattern(regexp="^[a-zA-Z]{2,}$", message="{valid.address}")
    private String address;

    @Size(min=1, message="{valid.likesMin}")
    private String[] likes;

    @com.my.controller.validator.Tel(message="{valid.tel}", min=3)
    private String tel;

    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public boolean isMarried() {
        return married;
    }
    public void setMarried(boolean married) {
        this.married = married;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String[] getLikes() {
        return likes;
    }
    public void setLikes(String[] likes) {
        this.likes = likes;
    }
    public String getTel() {
        return tel;
    }
    public void setTel(String tel) {
        this.tel = tel;
    }

}

除了@Tel之外，其它都是spring自带的annotation，当然还有别的，自行搜索下

5、message.properties

valid.required=字段值不能为空
valid.name=用户名不能为空
valid.password=密码最小4位
valid.ageMin=年龄不能小于{}岁
valid.ageMax=年龄不能大于{}岁
valid.email=邮箱格式不正确
valid.address=联系地址不正确
valid.birthday=生日不能大于今天
valid.likesMin=喜好最小不能小于1个
valid.tel=手机号码不能小于{min}位

对应的是User4 model的annotation的message值。如果需要国际化的多语言，只需要加入多一个messages_en_US.properties这样名字的文件即可。

6、@Tel

package com.my.controller.validator;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy=TelValidator.class)
public @interface Tel {

    int min() default 0;

    String message();

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

}

新建一个interface，注意，annotation的interface java是这样写的：@interface

TelValidator:

package com.my.controller.validator;

import javax.annotation.Resource;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

import org.springframework.context.support.ResourceBundleMessageSource;

public class TelValidator implements ConstraintValidator<Tel, String> {

    @Resource
    private ResourceBundleMessageSource messageSource;

    private Tel tel;

    @Override
    public void initialize(Tel tel) {
        this.tel = tel;
    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext constraintContext) {
        boolean isValid;

        if(value != null && value.length() >= tel.min()) {
            isValid = true;
        }
        else {
            isValid = false;
        }

        if(!isValid) {
            constraintContext.disableDefaultConstraintViolation();
            constraintContext.buildConstraintViolationWithTemplate(tel.message()).addConstraintViolation();
        }
        return isValid;
    }

}

这是@Tel的验证实现方法。

7、Converter

package com.my.controller.converter;

import org.springframework.core.convert.converter.Converter;

public class IntConverter implements Converter<String, Integer> {

    @Override
    public Integer convert(String text) {
        if (text == null || "".equals(text)) {
            return 0;
        } else {
            try {
                Integer value = Integer.parseInt(text);
                return value;
            } catch (Exception e) {
                return 0;
            }
        }
    }

}

package com.my.controller.converter;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.core.convert.converter.Converter;

public class DateConverter implements Converter<String, Date> {

    @Override
    public Date convert(String text) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
        dateFormat.setLenient(false);
        try {
            return dateFormat.parse(text);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

}

这两个是全局的类型默认转换器。

8、测试JSP

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib prefix="st" uri="http://www.springframework.org/tags" %>
<%@ 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>Index</title>
</head>
<body>
    <sf:form action="${pageContext.request.contextPath}/av/add" method="post" modelAttribute="user4">
        User name:<sf:input path="name"/><sf:errors path="name" /><br/>
        Password:<sf:input path="password"/><sf:errors path="password" /><br/>
        E-mail:<sf:input path="email"/><sf:errors path="email" /><br/>
        Age:<sf:input path="age"/><sf:errors path="age" /><br/>
        Birthday:<sf:input path="birthday"/><sf:errors path="birthday" /><br/>
        Address:<sf:input path="address"/><sf:errors path="address" /><br/>
        Married:
            <sf:radiobutton path="married" label="Yes" value="true"/>
            <sf:radiobutton path="married" label="No" value="false"/>
            <sf:errors path="married" /><br/>
        Likes:
            <sf:checkbox path="likes" label="Football" value="Football"/>
            <sf:checkbox path="likes" label="Badminton" value="Badminton"/>
            <sf:checkbox path="likes" label="Pingpong" value="Pingpong"/>
            <sf:errors path="likes" /><br/>
        Tel:<sf:input path="tel"/><sf:errors path="tel" /><br/>
        <input type="submit" value="Add" />
        <hr/>
        Errors:<br/><sf:errors path="*"></sf:errors>
        <hr/>
        Likes:<c:forEach items="${user4.likes}" var="item">${item},</c:forEach>
    </sf:form>
</body>
</html>

注意，在form中的modelAttribute属性值，它对应的是User4类名，小写开头，否则会出错

9、页面UI结果：

点击Add button后：