public void download(HttpServletResponse response){String filePath ="";//文件路径String fileName ="";//文件名称// 读到流中InputStream inStream = new FileInputStream(filePath);// 设置输出的格式response.reset();response.setContentType("bin");response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");IOUtils.copy(inStream, response.getOutputStream());
}

方式一：
new URL(fileUrl + item.getcBhFileserver()).openStream()方法二：public Boolean addFile(String url, String id, String fileName) {RequestCallback requestCallBack = new RequestCallback() {@Overridepublic void doWithRequest(ClientHttpRequest request) throws IOException {request.getHeaders().add("accept", MediaType.APPLICATION_OCTET_STREAM_VALUE);}};ResponseExtractor<Boolean> responseExtractor = new ResponseExtractor<Boolean>() {@Overridepublic Boolean extractData(ClientHttpResponse response) throws IOException {if (response.getStatusCode() == HttpStatus.OK) {//得到文件流InputStream input = response.getBody();return true;}return false;}};return restTemplate.execute(url, HttpMethod.GET, requestCallBack, responseExtractor, id);}

public void zipFilesAll() throws Exception {String zipPath = "";//zip包路径String zipFileName = "";//zip包名称File zipFile = new File(zipFileName .toString());// 创建 FileOutputStream 对象FileOutputStream fileOutputStream = null;// 创建 ZipOutputStreamZipOutputStream zipOutputStream = null;try {//创建文件夹zipFile = new File(zipPath );FileUtils.forceMkdir(zipFile);//创建文件zipFile = new File(zipFileName .toString());if (!zipFile.exists()) {zipFile.createNewFile();}// 实例化 FileOutputStream 对象fileOutputStream = new FileOutputStream(zipFileName.toString());// 实例化 ZipOutputStream 对象zipOutputStream = new ZipOutputStream(fileOutputStream);// 创建 ZipEntry 对象ZipEntry zipEntry = null;for (CL cl: ClList) {// 实例化 ZipEntry 对象，源文件数组中的当前文件zipEntry = new ZipEntry(tCltjjl.getcClmc() + ".zip");zipOutputStream.putNextEntry(zipEntry);IOUtils.copy(new FileInputStream(cl.getcPath(), zipOutputStream);}} catch (Exception e) {}finally{//记得删除文件}}