标签：att adc channel res java pre throws real 功能
提示：项目需求，微信小程序、app等渠道通过http请求实现文件下载。
文件下载：
第一步：对请求URL进行分解，http:XXXX/downloadfile.file?filePathParam=XX&fileName=XXXXX&isFullUrl=true,通常对外暴露的下载地址都是给出要下载的文件名，但由于项目是给第三方渠道的，所以并不需要进行加密，正常情况文件名及相关参数是需要进行加密的。
1 public static String getFileFullPath(String filePathParam, String fileName, boolean isFullUrl) throws IOException { 2 String filePath = PropertiesReader.getProperty("XXXX.properties", filePathParam); 3 if(!isFullUrl) { 4 filePath = getFullURL(filePath); 5 } else { 6 filePath = filePath.replace("/", File.separator).replace("\\\\", File.separator); 7 filePath = filePath.endsWith(File.separator)?filePath:filePath + File.separator; 8 } 9 10 return filePath + fileName; 11 }
一般情况下文件路径的前半截都是维护到配置文件中，通过读取配置文件中路径拼接成全路径。注意：对于目录，linux下是正斜杠，比如 /data/zhenwe/....windows下。windows下则是反斜杠c\windows。
第二步：获取需要下载文件绝对路径后，可以根据需求重新命名文件名，设置编码及请求头的相关设置。
String encode = "UTF-8"; //获取文件的绝对路径 String filePath = CommonUtil.getFileFullPath(filePathParam, fileName, isFullUrl); downLoadFile = new File(filePath); downLoadFileName = new String(fileName.replaceAll("\\\\","_").getBytes(encode),"iso-8859-1"); downLoadFileName=downLoadFileName.substring(downLoadFileName.indexOf("/")+1,downLoadFileName.length()); headers = new HttpHeaders(); //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 headers.setContentDispositionFormData("attachment",downLoadFileName); headers.add("Content-Type", "application/octet-stream; charset="+encode); headers.setDate((new Date()).toLong()); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); bFile = FileUtils.readFileToByteArray(downLoadFile);
注意：在IE11通过http请求下载文件时，IE11浏览器无法解析文件名包含"/"的文件，导致下载下来的文件大小是0KB，后来将文件命中的特殊字符去掉之后，才能下载成功。
下面是整个controller代码：
@Controller public class FilePdfDownLoandContorller { @RequestMapping({"/downloadfile.{ext}"}) public ResponseEntity<byte[]> downloadfile(@RequestParam String filePathParam, @RequestParam String fileName, @RequestParam boolean isFullUrl, ModelMap modelMap, HttpServletRequest request, HttpServletResponse response) throws IOException { Logger log = LoggerUtil.getLogger(); log.info(ERRCODE.LOG.START_BUSIN.getLogText(new String[]{"downloadfile 文件下载"})); HttpHeaders headers = null; File downLoadFile = null; String downLoadFileName = ""; byte[] bFile = null; try { if(StringUtils.isNotBlank(request.getParameter("validflag")) && request.getParameter("validflag").equals("true")) { Mi040DAO e = (Mi040DAO) SpringContextUtil.getBean("mi040DAO"); Mi040Example filePath = new Mi040Example(); Mi040Example.Criteria ca = filePath.createCriteria(); ca.andChannelEqualTo(request.getParameter("appid")).andCenteridEqualTo(request.getParameter("centerid")); List list040 = e.selectByExample(filePath); Mi701DAO mi701DAO = (Mi701DAO)SpringContextUtil.getBean("mi701Dao"); Mi701WithBLOBs mi701 = mi701DAO.selectByPrimaryKey(Integer.valueOf(Integer.parseInt(request.getParameter("seqno")))); if(mi701 != null) { Mi711DAO mi711DAO = (Mi711DAO)SpringContextUtil.getBean("mi711Dao"); Mi711 mi711 = new Mi711(); mi711.setSeqno(Integer.valueOf(Integer.parseInt(request.getParameter("seqno")))); mi711.setCenterid(request.getParameter("centerid")); mi711.setClassfication(request.getParameter("classfication")); mi711.setDatecreated(CommonUtil.getSystemDate()); mi711.setPid(((Mi040)list040.get(0)).getPid()); mi711.setTitle(mi701.getTitle()); mi711.setValidflag("1"); mi711DAO.insert(mi711); } } String encode = "UTF-8"; //获取文件的绝对路径 String filePath = CommonUtil.getFileFullPath(filePathParam, fileName, isFullUrl); downLoadFile = new File(filePath); downLoadFileName = new String(fileName.replaceAll("\\\\","_").getBytes(encode),"iso-8859-1"); downLoadFileName=downLoadFileName.substring(downLoadFileName.indexOf("/")+1,downLoadFileName.length()); headers = new HttpHeaders(); //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 headers.setContentDispositionFormData("attachment",downLoadFileName); headers.add("Content-Type", "application/octet-stream; charset="+encode); headers.setDate((new Date()).toLong()); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); bFile = FileUtils.readFileToByteArray(downLoadFile); } catch (Exception e) { e.printStackTrace(); }finally { log.info(ERRCODE.LOG.END_BUSIN.getLogText(new String[]{"downloadfile 文件下载"})); } return new ResponseEntity<byte[]>(bFile,headers, HttpStatus.OK); } }
以上是整个文件下载的一些个人理解，说下其中碰到的坑：
文件上传：
在实现上传功能之前要在applicationContext.xml中配置文件上传的一些设置：文件大小、编码、内存中最大值等。
<!--文件上传相关配置--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!--默认编码--> <property name="defaultEncoding" value="UTF-8"></property> <!--文件大小最大值 上传文件大小限制为10M 10*1024*1024--> <property name="maxUploadSize" value="10485760"></property> <!--内存中的最大值--> <property name="maxInMemorySize" value="4096"></property> </bean>
关于文件上传在网上随便搜一下应该就有一大堆实例，这里只记录下在完成下载功能后自己的一些扩展。在网上简单的搜了下前台的一个上传界面，代码如下：
1 <%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %> 2 <html> 3 <head> 4 <title>文件上传</title> 5 </head> 6 <body> 7 <form method="post" enctype="multipart/form-data" action="${pageContext.request.contextPath}/upload/uploadfile.json"> 8 上传用户名：<input type="text" name="username"/> 9 文件1：<input type="file" name="file1"/> 10 文件2：<input type="file" name="file2"/> 11 <input type="submit" name="btnsubmit" value="上传" /> 12 </form> 13 </body> 14 </html>
文件上传主要是通过spring的集成类CommonsMultipartResolver来获取MultipartFile并通过File实例化后调用transferTo即可，代码如下：
1 @Controller 2 @RequestMapping("/upload") 3 public class UploadController { 4 @Autowired 5 CommonsMultipartResolver multipartResolver; 6 7 @RequestMapping("/uploadfile.{ext}") 8 public String fileupload(HttpServletRequest request, HttpServletResponse response) { 9 10 if (multipartResolver.isMultipart(request)) { 11 MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request; 12 Iterator<String> iter = multiRequest.getFileNames(); 13 14 while (iter.hasNext()) { 15 long sTime = System.currentTimeMillis(); 16 MultipartFile file = multiRequest.getFile(iter.next()); 17 if (file != null) { 18 String myFileName = file.getOriginalFilename(); 19 if (myFileName.trim() != "") { 20 System.out.println("需要上传文件名：" + myFileName); 21 String fileName = "demoUpload" + file.getOriginalFilename(); 22 String path = "D:/" + fileName; 23 //String proPath = request.getSession().getServletContext().getRealPath("/WEB_INF/upload") + fileName; 24 25 File localFile = new File(path); 26 try { 27 file.transferTo(localFile); 28 } catch (IOException e) { 29 e.printStackTrace(); 30 } 31 } 32 } 33 long eTime = System.currentTimeMillis(); 34 System.out.println("文件上传耗时：" + (eTime - sTime)); 35 } 36 37 } 38 return "/helloWorld"; 39 } 40 41 }
标签：att adc channel res java pre throws real 功能
原文地址：https://www.cnblogs.com/chc24w/p/10130323.html
