springmvc upload and download
The jar package must be imported
If it is a maven project import dependencies
<!-- file upload --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3</version> </dependency>
The CommonsMultipartResolver file parser is defined under the spring's servlet view parser, which is to run the project when this is added. If there is no fileuload-related jar package, an error will be reported.
Write xml configuration in spring mvc configuration file
<!-- Definition file interpreter -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- set default encoding-->
<property name="defaultEncoding" value="utf-8"></property>
<!-- The maximum upload image size is 5M-->
<property name="maxUploadSize" value="5242440"></property>
</bean>
code demo
@RequestMapping("file")
@Controller
public class FileController {
/**
* File upload function
* @param file
* @return
* @throws IOException
*/
@RequestMapping(value="/upload",method=RequestMethod.POST)
@ResponseBody
public String upload(MultipartFile file,HttpServletRequest request) throws IOException{
String path = request.getSession().getServletContext().getRealPath("upload");
String fileName = file.getOriginalFilename();
File dir = new File(path,fileName);
if(!dir.exists()){
dir.mkdirs();
}
//MultipartFile's own parsing method
file.transferTo(dir);
return "ok!";
}
/**
* File download function
* @param request
* @param response
* @throws Exception
*/
@RequestMapping("/down")
public void down(HttpServletRequest request,HttpServletResponse response) throws Exception{
//Simulation file, myfile.txt is the file that needs to be downloaded
String fileName = request.getSession().getServletContext().getRealPath("upload")+"/myfile.txt";
//get the input stream
InputStream bis = new BufferedInputStream(new FileInputStream(new File(fileName)));
//If it is downloaded in Chinese name
String filename = "download file.txt";
//Transcoding, so as to avoid Chinese garbled file name
filename = URLEncoder.encode(filename,"UTF-8");
//Set the file download header
response.addHeader("Content-Disposition", "attachment;filename=" + filename);
//1. Set the file ContentType type, so setting, will automatically determine the download file type
response.setContentType("multipart/form-data");
BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
int len = 0;
while((len = bis.read()) != -1){
out.write(len);
out.flush();
}
out.close();
}
}