将文件夹和文件压缩下载思路？

后台 要做的就是将响应流放入压缩流中，然后压缩流文件目录对象放入压缩流中，当压缩流对象是文件时还需将压缩流放入输出缓冲流中，将文件流读到缓冲流中，然后压缩流关闭压缩流文件目录对象，之后从输出到输入、从外到里依次关闭流。

@GetMapping("/downloadFile")
    public void downloadFile(HttpServletResponse response){
        response.setCharacterEncoding("utf-8");
        ZipOutputStream zos = null;
        OutputStream os = null;
        OutputStream out = null;
        InputStream in = null;
        String filename1="aa/bb/cc/";
        String filename2="aa/bb/dd/";
        String filename3="aa/bb/dd/test.txt";
        FileInputStream fis =null;
        try {
            fis = new FileInputStream("./files/ftp学习.txt");//输入流
            os = response.getOutputStream();//响应流
            zos = new ZipOutputStream(os);//压缩流
            ZipEntry zipEntry = new ZipEntry(filename1);//压缩流目录对象
            zos.putNextEntry(zipEntry);//将压缩流目录对象放入压缩流中
            zos.closeEntry();//直接关闭压缩流目录对象
            ZipEntry zipEntry2 = new ZipEntry(filename2);
            zos.putNextEntry(zipEntry2);
            zos.closeEntry();
            ZipEntry zipEntry3 = new ZipEntry(filename3);
            zos.putNextEntry(zipEntry3);
            //缓冲流处理文件流
            in = new BufferedInputStream(fis);
            out = new BufferedOutputStream(zos);
            byte[] buff = new byte[1024];
            int read;
            while ((read = in.read(buff)) != -1) {
                System.out.println(buff);
                out.write(buff, 0, read);
                out.flush();
            }
            zos.closeEntry();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            //从输出到输入关闭流，从外到里关闭流。
            try {
                if(out!=null){
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(os!=null){
                    os.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(zos!=null){
                    zos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(in!=null){
                    in.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(fis!=null){
                    fis.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

前台 用原生的ajax异步请求 发送请求，处理后台传过来的响应流，然后浏览器下载成相应文件。

      downloadFileMethod:function() {
      	alert(tokenVal);
	var downloadUrl=this.downloadUrl; //下载地址;
        var fileName="test.zip"; //下载的文件;
         //      var postParam; //参数;
				var methodType="batchDownload"; //请求类型;单个,还是批量

				var that = this;
				var xhr = new XMLHttpRequest();
				xhr.open('GET', downloadUrl, true);
				xhr.setRequestHeader("Authorization", "Bearer " + tokenVal);
				//可以将`xhr.responseType`设置为`"blob"`也可以设置为`" arrayBuffer"`
				xhr.responseType = 'blob';

				xhr.onload = function(e) {
					if(this.readyState == 4 && this.status == 200) {
						const blob = this.response;
						if('download' in document.createElement('a')) { // 非IE下载
							const elink = document.createElement('a')
							elink.download = fileName;
							elink.style.display = 'none';
							elink.href = URL.createObjectURL(blob);
							document.body.appendChild(elink);
							elink.click();
							URL.revokeObjectURL(elink.href) // 释放URL 对象
							document.body.removeChild(elink)
				      that.batchDownloadDis=false;
						} else { // IE10+下载
							navigator.msSaveBlob(blob, fileName)
				      that.batchDownloadDis=false;
						}
					} else if(this.status == 404) { //磁盘文件被删除，返回404
				    that.batchDownloadDis=false;
						var notfilenames = decodeURIComponent(xhr.getResponseHeader('notfilenames')); //未找到的文件名称
						if(notfilenames != null) {
							if(methodType == "batchDownload") {
								that.$message({
									showClose: true,
									message: notfilenames + '   文件未找到！请重新勾选！',
									type: 'error'
								});
							}
							if(methodType == "singleDownload") {
								that.$message({
									showClose: true,
									message: '文件未找到！',
									type: 'error'
								});
							}
						}
					} else {
				    that.batchDownloadDis=false;
						that.$message({
							showClose: true,
							message: '下载失败！',
							type: 'error'
						});
					}
				};
				xhr.send();
			}