Spring implementation file upload of sample code

  • 2020-04-01 02:18:46
  • OfStack

In actual development, it is common to encounter the ability to upload files to the server side. Spring inherits the commons-fileupload plug-in for file uploading. Divided into the front-end JSP preparation and background Controller preparation.

The preliminary preparation is to introduce the jar package Commons -fileupload. The configuration in pom.xml is as follows:


<!--  File upload, spring This functionality is integrated  -->
<dependency>
 <groupId>commons-fileupload</groupId>
 <artifactId>commons-fileupload</artifactId>
 <version>1.2.2</version>
</dependency>

Then configure the interceptor and add it in dispatcher-servlet.xml

<!--  Implement file upload so that once a certain Request Is a MultipartRequest , it will be the first to be MultipartResolver Process, and then forward the corresponding Controller -->
<bean id="multipartResolver"
 class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
 <!--  Set the maximum size of the uploaded file to 1MB -->
 <property name="maxUploadSize">
  <value>1048576</value>
 </property>
</bean>

Direct code:

1, front-end JSP preparation

The upload. JSP


<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
  <script src="resources/js/jquery.js"></script>
 </head>
 <body>
  <form method="post" action="upload.do" enctype="multipart/form-data">
   <input type="file" name="file" />
   <input type="submit" />
  </form>
 </body>
</html>

2, background UploadController write

package nju.software.xkxt.web.controller;
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.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;

@Controller
public class UploadController {
 
 @RequestMapping(value = "upload_enter.do", method = RequestMethod.GET)
 public String enter(HttpServletRequest request,
   HttpServletResponse response, ModelMap model) throws IOException {
  //Enter the download interface
  return "upload";
 }
 
 @RequestMapping(value = "upload.do", method = RequestMethod.POST)
 public void upload(HttpServletRequest request,
   HttpServletResponse response, ModelMap model) throws IOException {
  MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
  //Get the uploaded file
  MultipartFile mFile = multipartRequest.getFile("file");
  //Gets the path to the upload server
  String path = request.getSession().getServletContext()
    .getRealPath("/WEB-INF/upload/");
  //Get the uploaded file The name of the file 
  String filename = mFile.getOriginalFilename();
  InputStream inputStream = mFile.getInputStream();
  byte[] b = new byte[1048576];
  int length = inputStream.read(b);
  path += "\" + filename;
  //The file stream is written to the server side
  FileOutputStream outputStream = new FileOutputStream(path);
  outputStream.write(b, 0, length);
  inputStream.close();
  outputStream.close();
 }
}

This makes it easy to upload files.


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