Vue form post request combined with Servlet to realize file upload function

<template>
 <div>
  <input type="file" name="file" @change="change($event)">
 </div>
</template>
<script>
 export default {
  created(){
   this.path = this.$route.query;
   for (let i in this.path) {
    this[i] = decodeURIComponent(this.path[i]);
   }
  },
  methods:{
   change(ev){
    let file = ev.target.files[0];
    let size = file.size;
    let name = file.name;
    if(size > 314572800){
     this.$message.warning('Uploaded files cannot exceed 300M');
     return;
    }
    let formData = new FormData();
    formData.append('file',file,name)
    this.$axios.post('/JT3'+this.getddRecordDelete,formData,{
     headers:{"Content-Type":"multipart/form-data"}
    }).then(data=>{
     console.log(data);
    })
   }
  }
 }
</script>
<style scoped>
</style>

package jt3.control.zygkh;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem; 
import org.apache.commons.fileupload.FileUploadException; 
import org.apache.commons.fileupload.disk.DiskFileItemFactory; 
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import jtacc.filter.JTKit;
import jtacc.jtpub.DT; 
@WebServlet(urlPatterns = "/upfile/file") 
public class UploadServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println(11);
		this.doPost(request, response);
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 	String uri="/u/file/"+DT.getFormatDate("yyyyMMdd")+"/"; //Define the path String tmpPath=JTKit.getBaseDIR()+uri; //This is the personal project path, define the path according to your needs DiskFileItemFactory factory = new DiskFileItemFactory();
		factory.setRepository(new File(tmpPath));//temporary file storage path ServletFileUpload fileUpload = new ServletFileUpload(factory);//core operation object fileUpload.setHeaderEncoding("utf-8");//anti-garbled code try {
			//If you want to force the conversion in real time, you need to download the jar package (commons-fileupload-1.3.3.jar)
			List<FileItem> list = fileUpload.parseRequest(request);
			for (FileItem fileItem : list) {
				InputStream in = fileItem.getInputStream();
				String filename = fileItem.getName();
				if (fileItem != null) {
					System.out.println(filename);
					int len ​​= 0;
					byte[] array = new byte[1024];
					FileOutputStream fos = new FileOutputStream(tmpPath+filename);
					while((len = in.read(array))!=-1){//Indicates that a maximum of 1024 bytes can be read each time fos.write(array,0,len);
						fos.flush();
					}
					fos.close();
					in.close();
					fileItem.delete();
					response.setCharacterEncoding("UTF-8");
					String realPath = uri+filename;
					response.getWriter().append(realPath);
				}
			}
		} catch (FileUploadException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
 }
 
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}

request.setCharacterEncoding("utf-8");

String username = request.getParameter("username");

String[] favorites = request.getParameterValues("favorite");