FTP服务器 打包 下载文件

需求：从ftp服务器打包下载文件

解决步骤：1.从ftp服务器把各个文件下载到本地服务器(一般是安装tomcat的服务器，项目自己电脑跑的本地服务器就是自己电脑)指定目录中

2.在本地服务器打包下载好的文件夹打包，返回打包好的File zip

3.zip文件用流写入reponse，达到用户下载效果

准备文件：

// 封装所有需要打包下载的文件地址请求类 public class DownloadPackageReq implements Serializable { // 本地服务器临时存放目录名(尽量唯一.eg:"menutree20200904112125")  private String localTempDirName; // 打包下载本地服务器文件夹名字 private List<DownloadPackageListReq> downloadPackageListReqList; // 需要下载所有文件路径和名称 }

// FTPClientUtils：ftp工具类 public static FTPClientUtils init() { FTPClientUtils ftp = new FTPClientUtils(); ftp.setHost(host); ftp.setPort(port); ftp.setUsername(username); ftp.setPassword(password); ftp.setBinaryTransfer(true); ftp.setPassiveMode(false); ftp.setEncoding("utf-8"); return ftp; }

/**  * 下载一个远程文件到本地的指定文件  *  * @param remoteAbsoluteFile  * 远程文件名(包括完整路径,eg:/MTL/test/menutree_attachment/file.xlsx)  * @param localAbsoluteFile  * 本地文件名(包括完整路径)  * @param autoClose  * 是否自动关闭当前连接  *  * @return 成功时，返回true，失败返回false  * @throws Exception  */ public boolean get(String remoteAbsoluteFile, String localAbsoluteFile, boolean autoClose) throws Exception { OutputStream output = null; try { output = new FileOutputStream(localAbsoluteFile); return get(remoteAbsoluteFile, output, autoClose); } catch (FileNotFoundException e) { throw new Exception("local file not found.", e); } finally { try { if (output != null) { output.close(); } } catch (IOException e) { throw new Exception("Couldn't close FileOutputStream.", e); } } }

/**  * 下载一个远程文件到指定的流 处理完后记得关闭流  *  * @param remoteAbsoluteFile  * @param output  * @param autoClose  * @return  * @throws Exception  */ public boolean get(String remoteAbsoluteFile, OutputStream output, boolean autoClose) throws Exception { try { FTPClient ftpClient = getFTPClient(); // 处理传输  return ftpClient.retrieveFile(remoteAbsoluteFile, output); } catch (IOException e) { throw new Exception("Couldn't get file from server.", e); } finally { if (autoClose) { disconnect(); // 关闭链接  } } }

第一步：

public File downloadMenuTreeAttachment(Integer menutreeId) throws Exception {     // 从数据库拿到menutreeId对应的所有文件地址 List<ResourcesMenutreeListVo> resourcesMenutreeLists = resourcesMenutreeListMapper.selExistingAttachment(menutreeId); DownloadPackageReq req = new DownloadPackageReq(); if (CollectionUtils.isNotEmpty(resourcesMenutreeLists)) { req.setLocalTempDirName(resourcesMenutreeLists.get(0).getMenutreeName() + DateUtils.dateTimeNow()); List<DownloadPackageListReq> dpList = new ArrayList<>(); for(ResourcesMenutreeListVo temp : resourcesMenutreeLists) { DownloadPackageListReq dpReq = new DownloadPackageListReq();             // 文件名称，用来下载ftp服务器文件修改文件名(因为ftp文件都是uuid名称) String fileName = temp.getModuleName() + "_" + temp.getEngineerName(); dpReq.setFileName(fileName); dpReq.setFileFtpUrl(temp.getMenutreeAttachment()); dpList.add(dpReq); } req.setDownloadPackageListReqList(dpList); } else { req.setLocalTempDirName("空菜单树" + DateUtils.dateTimeNow()); } return ftpService.zipFiles(req); }

public File zipFiles(DownloadPackageReq req) throws Exception { HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest(); // 本地服务器暂存路径  String localTempDir = request.getSession().getServletContext().getRealPath("/") + req.getLocalTempDirName() + File.separator; logger.info("本地服务器暂存路径:" + localTempDir); File dir = new File(localTempDir); if ( ! dir.exists()) { dir.mkdir(); } if (CollectionUtils.isNotEmpty(req.getDownloadPackageListReqList())) { List<DownloadPackageListReq> downloadList = req.getDownloadPackageListReqList(); FTPClientUtils ftp = FTPClientUtils.init(); for(int i=0; i<downloadList.size(); i++) { // 是否关闭传输流(最后一份文件传输完毕关闭)  boolean isCloseStream = false; if (i == downloadList.size() - 1) { isCloseStream = true; } DownloadPackageListReq temp = downloadList.get(i); String fileFtpUrl = temp.getFileFtpUrl(); String suffix = ""; if (fileFtpUrl.contains(".") && !fileFtpUrl.endsWith(".")) { // 文件后缀名  suffix = fileFtpUrl.substring(fileFtpUrl.lastIndexOf(".")); } // 本地服务器存放完整路径(包含文件名)  String localUrl = localTempDir + temp.getFileName() + suffix; // 下载的第一个参数远程路径如果是FTP服务器，就采用服务器完整文件路径(eg:/MTL/test/menutree_attachment/file.xlsx),因为初始化ftp服务器就带了ip端口  boolean result = ftp.get(temp.getFileFtpUrl(), localUrl, isCloseStream); } }     // 打包下载好的文件 File zipFile = ZipUtil.zip(localTempDir, localTempDir + req.getLocalTempDirName() + ".zip"); return zipFile; }

第二步：

public class ZipUtil { private static Logger logger = Logger.getLogger(ZipUtil.class); /**  * 缓冲器大小  */  private static final int BUFFER = 512; /**  * 压缩方法 （可以压缩空的子目录）  *  * @param srcPath 压缩源路径  * @param zipFileName 目标压缩文件  * @return  */  public static File zip(String srcPath, String zipFileName) { ZipOutputStream zipOutputStream = null; InputStream inputStream = null; File outputZipFile = null; try { // 检查文件是否存在，是的话先删除  outputZipFile = new File(zipFileName); if (outputZipFile.exists()) { outputZipFile.delete(); } File srcFile = new File(srcPath); List<File> fileList = FileUtil.getAllFiles(srcFile);// 所有要压缩的文件  byte[] buffer = new byte[BUFFER];// 缓冲器  ZipEntry zipEntry = null; int readLength = 0;// 每次读出来的长度  zipOutputStream = new ZipOutputStream(new FileOutputStream(zipFileName)); for (File file : fileList) { if (file.isFile()) {// 若是文件，则压缩这个文件  zipEntry = new ZipEntry(getRelativePath(srcPath, file)); zipEntry.setSize(file.length()); zipEntry.setTime(file.lastModified()); zipOutputStream.putNextEntry(zipEntry); inputStream = new BufferedInputStream(new FileInputStream(file)); while ((readLength = inputStream.read(buffer, 0, BUFFER)) != -1) { zipOutputStream.write(buffer, 0, readLength); } } else {// 若是目录（即空目录）则将这个目录写入zip条目  zipEntry = new ZipEntry(getRelativePath(srcPath, file) + File.separator); zipOutputStream.putNextEntry(zipEntry); } } // end for  } catch (FileNotFoundException e) { logger.error("zip fail!", e); } catch (IOException e) { logger.error("zip fail!", e); } finally { close(inputStream); close(zipOutputStream); } // 返回文件输出流  outputZipFile = new File(zipFileName); return outputZipFile; } /**  * 关闭流  */  private static void close(Closeable c) { if (c == null) return; try { c.close(); } catch (IOException e) { logger.error("close fail!", e); } c = null; } /**  * 取相对路径 依据文件名和压缩源路径得到文件在压缩源路径下的相对路径  *  * @param dirPath 压缩源路径  * @param file  * @return 相对路径  */  public static String getRelativePath(String dirPath, File file) { File dir = new File(dirPath); String relativePath = file.getName(); while (true) { file = file.getParentFile(); if (file == null) { break; } if (file.equals(dir)) { break; } else { relativePath = file.getName() + "/" + relativePath; } } // end while  return relativePath; } }

第三步：Controller控制器，Result是自己封装的返回类，可以自定义String之类的返回

public Result downloadMenuTreeAttachment(Integer menutreeId, HttpServletResponse response) { BufferedInputStream bis = null; OutputStream os = null; try { File file = resourcesMenutreeListService.downloadMenuTreeAttachment(menutreeId); response.reset(); response.setCharacterEncoding("utf-8"); response.setContentLength((int) file.length()); // 设置content-disposition响应头控制浏览器以下载的形式打开文件，中文文件名要使用URLEncoder.encode方法进行编码，否则会出现文件名乱码  response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8")); bis = new BufferedInputStream(new FileInputStream(file)); os = response.getOutputStream(); byte[] buff = new byte[1024]; int i = 0; while ((i = bis.read(buff)) != -1) { os.write(buff, 0, i); os.flush(); } } catch (Exception e) { log.error("{}",e); return ResultGenerator.genFailResult("下载失败"); } finally { try { bis.close(); os.close(); } catch (IOException e) { e.printStackTrace(); } } return ResultGenerator.genSuccessResult(); }

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