Vue+element+springboot to implement file download progress bar display function example

<!--Download progress bar-->
    <el-dialog title="Downloading, please wait" :visible.sync="fileDown.loadDialogStatus" :close-on-click-modal="false" 
      :close-on-press-escape="false" :show-close="false" width="20%">
      <div style="text-align: center;">
        <el-progress type="circle" :percentage="fileDown.percentage"></el-progress>
      </div>
      <div slot="footer" class="dialog-footer">
        <el-button type="primary" @click="downClose">Cancel download</el-button>
      </div>  
    </el-dialog>

fileDown: {
        loadDialogStatus: false, // Pop-up box control status percentage: 0, // Progress bar percentage source: {}, // Cancel download resource object },

downFile(row) {
    //Put parameters here var param = {};
    this.fileDown.loadDialogStatus = true;
    this.fileDown.percentage = 0;
    const instance = this.initInstance();
    instance({
        method: "post",
        withCredentials: true,
        url: "Replace download address",
        params: param,
        responseType: "blob"
    }).then(res => {
        this.fileDown.loadDialogStatus = false;
        console.info(res);
        const content = res.data;
        if (content.size == 0) {
          this.loadClose();
          this.$alert("Download failed");
          return ;
        }
        const blob = new Blob([content]);
        const fileName = row.fileName; //Replace the file name if ("download" in document.createElement("a")) {
          // Non-IE download const elink = document.createElement("a");
          elink.download = fileName;
          elink.style.display = "none";
          elink.href = URL.createObjectURL(blob);
          document.body.appendChild(elink);
          elink.click();
          setTimeout(function() {
            URL.revokeObjectURL(elink.href); // Release the URL object document.body.removeChild(elink);
          }, 100);
        } else {
          // IE10+ download navigator.msSaveBlob(blob, fileName);
        }
      }).catch(error => {
          this.fileDown.loadDialogStatus = false;
          console.info(error);
      });
  },
initInstance() {
      var _this = this;
      //Resource token for cancellation this.fileDown.source = axios.CancelToken.source();
      const instance = axios.create({ //The axios object should be imported in advance or replaced with your globally defined onDownloadProgress: function(ProgressEvent) {
          const load = ProgressEvent.loaded;
          const total = ProgressEvent.total;
          const progress = (load / total) * 100;
          console.log('progress='+progress);
          // Calculation has already been done at the beginning. This must exceed the previous calculation to continue if (progress > _this.fileDown.percentage) {
            _this.fileDown.percentage = Math.floor(progress);
          }
          if(progress == 100){
            //Download completed_this.fileDown.loadDialogStatus = false;
          }
        },
        cancelToken: this.fileDown.source.token, //Declare a cancel request token
      });
      return instance;
    },
    downClose() {
      //Interrupt download this.$confirm("Clicking Close will interrupt the download. Are you sure you want to close it?", this.$t("button.tip"), {
        confirmButtonText: this.$t("button.confirm"),
        cancelButtonText: this.$t("button.cancel"),
        type: "warning"
      }).then(() => {
          //Interrupt download callback this.fileDown.source.cancel('log==customer manually canceled download');
      }).catch(() => {
          //Cancel -- do nothing});      
    },

//Get the local file and calculate the sizeFile file = new File(zipFileName);//Read the compressed fileInputStream inputStream = new FileInputStream(file);
int totalSize = inputStream.available(); //Get the file size logger.info("After compression === current file download size size={}", totalSize);
response.setHeader("Content-Length", totalSize+""); //Note that you must set the setHeader property before response.getOutputStream(), otherwise it will not take effect OutputStream out = response.getOutputStream();
Subsequent omissions...