Spring MVC Annotation验证的方法

时间:2019-04-13
本文章向大家介绍Spring MVC Annotation验证的方法,主要包括Spring MVC Annotation验证的方法使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

简介说明

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{1}岁
valid.ageMax=年龄不能大于{1}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:

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。