Spring MVC Annotation驗證的方法

簡介說明

使用Spring MVC的Annotation驗證可以直接對view model的簡單數據驗證，注意，這裡是簡單的，如果model的數據驗證需要有一些比較複雜的業務邏輯性在裡頭，只是使用annotation做驗證是比較難的。

以下是使用Spring MVC自帶的annotation驗證，加上自定義的一個@Tel的annotation驗證例子，此例子具有：

1、支持多語言（國際化）

2、對默認數據先進行轉化，比如int、date類型如果傳入空值時，會拋異常，默認給定值

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>

這裡沒什麼好說的，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"> <!--註解說明--> <context:annotation-config /> <!-- 默認的註解映射的支持--> <mvc:annotation-driven validator="validator" conversion-service="conversionService" /> <!-- 把標記了@Controller註解的類轉換為bean --> <context:component-scan base-package="com.my" /> <!-- 視圖解釋類--> <bean> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/><!--可為空,方便實現自已的依據擴展名來選擇視圖解釋類的邏輯--> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> </bean> <!-- 資源文件：messages.properties --> <bean id="messageSource"> <property name="basenames"> <list> <value>messages</value> </list> </property> </bean> <!-- 驗證器--> <bean id="validator"> <property name="validationMessageSource" ref="messageSource"/> </bean> <!-- 自定義數據類型轉換器--> <bean id="conversionService"> <property name="converters"> <list> <bean /> <bean /> </list> </property> </bean> </beans>

在<mvc:annotation-driven/>中加入conversion-service，然後在conversion-service中加入系統默認的轉換器，如上有IntConverter和DateConverter，當然，也可以是自定的別的類型，這是全局的。

在validator驗證器中加入了支持多語言的properties，當然，spring的多語言是基於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; } }

這是一個簡單的controller，在add中，有一個@Valid的annotation，這是必需的，不加這個，annotation驗證將不起作用

4、User4.java model實體類

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自帶的annotation，當然還有別的，自行搜索下

5、message.properties

 valid.required=字段值不能為空valid.name=用戶名不能為空valid.password=密碼最小4位valid.ageMin=年齡不能小於{1}歲valid.ageMax=年齡不能大於{1}歲valid.email=郵箱格式不正確valid.address=聯繫地址不正確valid.birthday=生日不能大於今天valid.likesMin=喜好最小不能小於1個valid.tel=手機號碼不能小於{min}位

對應的是User4 model的annotation的message值。如果需要國際化的多語言，只需要加入多一個messages_en_US.properties這樣名字的文件即可。

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 {};}

新建一個interface，注意，annotation的interface java是這樣寫的：@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; }}

這是@Tel的驗證實現方法。

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; }}

這兩個是全局的類型默認轉換器。

8、測試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屬性值，它對應的是User4類名，小寫開頭，否則會出錯

9、頁面UI結果：

點擊Add button後：

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。