java 文件下载，压缩

妖狐艹你老母 2023-10-16 09:36 55阅读 0赞

public static void downloadFile(String fileUrl, String savePath) throws IOException {
            URL url = new URL(fileUrl);
            InputStream in = url.openStream();
            FileOutputStream out = new FileOutputStream(savePath);
    
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
    
            in.close();
            out.close();
        }

public Map<String, Object> attachmentRecordDown(Map<String, Object> params) {
            Map<String,Object>map = new HashMap<>();
            String files = MapUtils.getString(params,"files");
    
            if (StringUtils.isBlank(files)){
                throw new CustomException("1","文件地址不能为空！");
            }
    
            String[] split = files.split(",");
            if (split.length<1){
                throw new CustomException("1","文件地址不能为空！");
            }
    
            File fileZip = new File(path+"/zip");
            //如果已经存在则删除
            if (fileZip.exists()) {
                fileZip.delete();
            }
            //检查是否存在
            if (!fileZip.exists())
            {
                fileZip.mkdirs();
            }
            SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
            String dateStr = df.format(new Date());
    
            List<String> paths = new ArrayList<>();
            for (String s:split){
                s = downPath+s;
                String fileName1=s.substring(s.lastIndexOf("/")+1);
                String filePaths = fileZip+"/"+fileName1;
                try {
                    URL url = new URL(s);
                    InputStream fis = url.openStream();
                    BufferedInputStream bis =new BufferedInputStream(fis);
                    FileOutputStream fos = new FileOutputStream(filePaths);
                    BufferedOutputStream bos =new BufferedOutputStream(fos);
                    int read;
                    while ((read = bis.read())!=-1){
                        bos.write(read);
                    }
                    bis.close();
                    bos.close();
                    fis.close();
                    fos.close();
                    paths.add(filePaths);
    
                } catch (Exception e) {
                    e.printStackTrace();
                }
    
            }
            try {
                compress(paths,fileZip+"/"+dateStr+".zip");
            } catch (IOException e) {
                e.printStackTrace();
            }
            map.put("path","/localFile/zip/"+dateStr+".zip");
            return map;
        }
    
        public static int compress(List<String> filePaths, String zipFilePath) throws IOException{
            // 压缩下载保存的路径
            File zipFile = new File(zipFilePath);
            //设置压缩流：直接写入response，实现边压缩边下载
            ZipOutputStream zipOs = null;
            //循环将文件写入压缩流
            DataOutputStream os = null;
            //文件
            File file;
            try {
                zipOs = new ZipOutputStream(new FileOutputStream(zipFile));
                //设置压缩方法
                zipOs.setMethod(ZipOutputStream.DEFLATED);
                for (String path : filePaths) {
                    String fileName=path.substring(path.lastIndexOf("."));
                    fileName=path.substring(path.lastIndexOf("/")+1);
                    file = new File(path);
                    if (!file.exists()) {
                        throw new RuntimeException("文件不存在");
                    }
                    //添加ZipEntry，并将ZipEntry写入文件流
                    zipOs.putNextEntry(new ZipEntry(fileName));
                    os = new DataOutputStream(zipOs);
                    FileInputStream fs = new FileInputStream(file);
                    byte[] b = new byte[100];
                    int length;
                    //读入需要下载的文件的内容，打包到zip文件
                    while ((length = fs.read(b)) != -1) {
                        os.write(b, 0, length);
                    }
    
                    //关闭流
                    fs.close();
                    zipOs.closeEntry();
                }
    
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                //关闭流
                for (String str:filePaths){
                    File fileExcel = new File(str);
                    //如果已经存在则删除
                    if (fileExcel.exists()) {
                        fileExcel.delete();
                    }
                    String substring = str.substring(0, str.lastIndexOf("/"));
                    fileExcel = new File(substring);
                    // 判断该temp对象是否为目录对象
                    if (fileExcel.isDirectory()) {
                        fileExcel.delete();
                    }
                }
                try {
                    if (os != null) {
                        os.flush();
                        os.close();
                    }
                    if (zipOs != null) {
                        zipOs.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return 0;
        }