使用MultipartFile怎么实现一个文件上传功能？很多新手对此不是很清楚，为了帮助大家解决这个难题，下面小编将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。
一.主要有两个java类,和一般的servlet放在一起即可.
FileUploadBean.java
package chb.demo.web;import org.springframework.web.multipart.MultipartFile;public class FileUploadBean { private MultipartFile file; public void setFile(MultipartFile file) { this.file = file; } public MultipartFile getFile() { return file; }}FileUploadController.java
package chb.demo.web;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.validation.BindException;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.mvc.SimpleFormController;public class FileUploadController extends SimpleFormController { protected ModelAndView onSubmit( HttpServletRequest request, HttpServletResponse response, Object command, BindException errors){ try { // cast the bean FileUploadBean bean = (FileUploadBean) command; // let's see if there's content there MultipartFile file = bean.getFile(); if (file == null) { throw new Exception("上传失败：文件为�空"); } if(file.getSize()>10000000) { throw new Exception("上传失败：文件大小不能超过10M"); } //得到文件�名 String filename=file.getOriginalFilename(); if(file.getSize()>0){ try { SaveFileFromInputStream(file.getInputStream(),"D:/",filename); } catch (IOException e) { System.out.println(e.getMessage()); return null; } } else{ throw new Exception("上传失败：上传文件不能为�空"); } // well, let's do nothing with the bean for now and return: try { return super.onSubmit(request, response, command, errors); } catch (Exception e) { System.out.println(e.getMessage()); return null; } } catch(Exception ex) { System.out.println(ex.getMessage()); return null; } } public void SaveFileFromInputStream(InputStream stream,String path,String filename) throws IOException { FileOutputStream fs=new FileOutputStream( path + "/"+ filename); byte[] buffer =new byte[1024*1024]; int bytesum = 0; int byteread = 0; while ((byteread=stream.read(buffer))!=-1) { bytesum+=byteread; fs.write(buffer,0,byteread); fs.flush(); } fs.close(); stream.close(); } }二.配置文件中如下配置:
web.xml,利用spring mvc模式,大家应该都很熟悉了
<servlet> <servlet-name>chb</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>chb</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping>chb-servlet.xml,这里要配置映射,并可以设定最大可上传文件的大小
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"><beans> <!-- Multi-Action 用来标识method的变量名定义--> <bean id="methodNameResolver" class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver"> <property name="paramName"> <value>action</value> </property> <property name="defaultMethodName"> <value>index</value> </property> </bean> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- one of the properties available; the maximum file size in bytes --> <property name="maxUploadSize" value="10000000"/> </bean> <bean id="handlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/upload.do">fileUploadController</prop> </props> </property> </bean> <bean id="fileUploadController" class="chb.demo.web.FileUploadController"> <property name="commandClass" value="chb.demo.web.FileUploadBean"/> <!-- 上传失败时跳转页面 --> <property name="formView" value="/user/err.jsp"/> <!-- 上传成功时跳转页面 --> <property name="successView" value="/user/confirmation.jsp"/> </bean></beans>三.设定jsp页面
<form id="form1" method="post" action="upload.do" enctype="multipart/form-data"> <tr> <td width="25%" align="right">上传文件：</td> <td><input id="file" type="file" NAME="file" ></td> </tr> <tr align="center" valign="middle"> <td height="60" colspan="2"><input type="submit" ID="BtnOK" value="确认上传"></td> </tr></form>看完上述内容是否对您有帮助呢？如果还想对相关知识有进一步的了解或阅读更多相关文章，请关注编程网行业资讯频道，感谢您对编程网的支持。
