spring mvc 文件上传
spring mvc 文件上传
一、单文件上传
配置步骤：
步骤一、在配置文件中配置包扫描器（暂且这样配，会出问题，我们下面说解决方案）
<?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:p="http://www.springframework.org/schema/p" 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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd "> <!--让spring扫描包下所有的类，让标注spring注解的类生效 --> <context:component-scan base-package="cn.hmy.controller"/> </beans>
步骤二，定制我们的文件上传jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>文件上传</title> </head> <body> <form action="${pageContext.request.contextPath }/list.do" method="post" enctype="multipart/form-data"> <h1>文件上传</h1> 文件:<input type="file" name="fileUpLoad"/></br> <input type="submit" value="上传"/> </form> </body> </html>
步骤三、书写我们的处理器代码
package cn.hmy.controller; import java.io.File; import java.io.IOException; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.validation.BindingResult; import org.springframework.validation.FieldError; import org.springframework.validation.annotation.Validated; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.servlet.ModelAndView; import cn.hmy.pojo.UserInfo; @Controller public class MyController{ //处理器方法 @RequestMapping(value="/list.do") public void doFirst(MultipartFile fileUpLoad,HttpSession session) throws Exception{ //1.获取文件名称 String filename = fileUpLoad.getOriginalFilename(); //2.获取文件的前半部分路径 String realPath = session.getServletContext().getRealPath("/images"); //3.拼接成完整的路径 File file=new File(realPath,filename); //4.保存文件 fileUpLoad.transferTo(file); } }
此时我们启动服务器，进行代码上传，会报如下错误
解决方案：更改我们的spring-servlet.xml配置文件
<?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:p="http://www.springframework.org/schema/p" 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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd "> <!--让spring扫描包下所有的类，让标注spring注解的类生效 --> <context:component-scan base-package="cn.hmy.controller"/>
<!--配置复杂类型表达解析器-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"></bean> </beans>
启动发现还是会报上述错误
解决方案：配置注解驱动
<?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:p="http://www.springframework.org/schema/p" 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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd "> <!--让spring扫描包下所有的类，让标注spring注解的类生效 --> <context:component-scan base-package="cn.hmy.controller"/>
<!--配置复杂类型表达解析器--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"></bean>
<!--配置注解驱动-->
<mvc:annotation-driven/> </beans>
如果在上述配置文件中缺少复杂类型解析器，会报如下错误
在解决了以上错误后，我们会发现如果我们上传的文件中含有中文 会出现乱码现象
解决乱码
解决方案我们暂且提供以下两种方式
方案一、
方案二、在web.xml中配置
<filter> <filter-name>characterEncoding</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
如何控制文件上传大小
在spring-servlet.xml中配置如下
maxUploadSize为上传的总文件的大小 5M
maxInMemorySize为上传的单个文件的大小 1M
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="utf-8"></property> <property name="maxUploadSize" value="5000000"></property> <property name="maxInMemorySize" value="1000000"></property> </bean>
如果超出所限制的大小 会报如下错误
控制文件上传的类型（通过后缀名进行控制）在处理器中进行判定
例如 只允许上传.jpg .png .gif为后缀的文件
package cn.hmy.controller; import java.io.File; import java.io.IOException; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.validation.BindingResult; import org.springframework.validation.FieldError; import org.springframework.validation.annotation.Validated; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.servlet.ModelAndView; import cn.hmy.pojo.UserInfo; @Controller public class MyController{ //处理器方法 @RequestMapping(value="/list.do") public String doFirst(MultipartFile fileUpLoad,HttpSession session) throws Exception{ //1.获取文件名称 String filename = fileUpLoad.getOriginalFilename(); //限定文件上传的类型 if(filename.endsWith("jpg")||filename.endsWith("png")||filename.endsWith("gif")){ //2.获取文件的前半部分路径 String realPath = session.getServletContext().getRealPath("/images"); //3.拼接成完整的路径 File file=new File(realPath,filename); //4.保存文件 fileUpLoad.transferTo(file); }else{ System.out.println("不支持上传文件的类型"); } return "/list.jsp"; } }
如何判断用户没用选上传文件
多文件上传
步骤一、
spring-servlet.xml配置文件
<?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:p="http://www.springframework.org/schema/p" 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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd "> <!--让spring扫描包下所有的类，让标注spring注解的类生效 --> <context:component-scan base-package="cn.hmy.controller"/> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="utf-8"></property> <property name="maxUploadSize" value="5000000"></property> <property name="maxInMemorySize" value="1000000"></property> </bean> <mvc:annotation-driven/> </beans>
步骤二、准备多文件上传的jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>文件上传</title> </head> <body> <form action="${pageContext.request.contextPath }/list.do" method="post" enctype="multipart/form-data"> <h1>文件上传</h1> 文件1:<input type="file" name="fileUpLoad"/></br> 文件2:<input type="file" name="fileUpLoad"/></br> 文件3:<input type="file" name="fileUpLoad"/></br> <input type="submit" value="上传"/> </form> </body> </html>
步骤三、编写处理器的代码
//多文件上传 @RequestMapping(value="/list.do") public String doFirst2(@RequestParam MultipartFile[] fileUpLoad,HttpSession session) throws Exception{ for (MultipartFile item : fileUpLoad) { //1.获取文件名称 String filename = item.getOriginalFilename(); //限定文件上传的类型 if(filename.endsWith("jpg")||filename.endsWith("png")||filename.endsWith("gif")){ //2.获取文件的前半部分路径 String realPath = session.getServletContext().getRealPath("/images"); //3.拼接成完整的路径 File file=new File(realPath,filename); //4.保存文件 item.transferTo(file); }else{ System.out.println("不支持上传文件的类型"); } } return "/list.jsp"; }
注意：在处理器方法中一定要对参数进行校对使用注解@RequestParam校正参数
丢到 会报错
即可实现多文件上传
