Question

java实现文件的断点续传和断点下载，有知道的交流下。

java实现文件的断点续传和断点下载，有知道的交流下。

Answer 1

1. /** 
2.      * 下载服务器已存在的文件 
3.      *  
4.      * @param request 
5.      * @param response 
6.      * @param proposeFile 
7.      * @throws IOException 
8.      * @throws FileNotFoundException 
9.      */  
10.     private void downloadExistsFile(HttpServletRequest request,  
11.             HttpServletResponse response, File proposeFile) throws IOException,  
12.             FileNotFoundException {  
13.         log.debug("下载文件路径：" + proposeFile.getPath());  
14.         long fSize = proposeFile.length();  
15.         // 下载  
16.         response.setContentType("application/x-download");  
17.         String isoFileName = this  
18.                 .encodeFilename(proposeFile.getName(), request);  
19.         response.setHeader("Accept-Ranges", "bytes");  
20.         response.setHeader("Content-Length", String.valueOf(fSize));  
21.         response.setHeader("Content-Disposition", "attachment; filename="  
22.                 + isoFileName);  
23.         long pos = 0;  
24.         if (null != request.getHeader("Range")) {  
25.             // 断点续传  
26.             response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);  
27.             try {  
28.                 pos = Long.parseLong(request.getHeader("Range").replaceAll(  
29.                         "bytes=", "").replaceAll("-", ""));  
30.             } catch (NumberFormatException e) {  
31.                 log.error(request.getHeader("Range") + " is not Number!");  
32.                 pos = 0;  
33.             }  
34.         }  
35.         ServletOutputStream out = response.getOutputStream();  
36.         BufferedOutputStream bufferOut = new BufferedOutputStream(out);  
37.         InputStream inputStream = new FileInputStream(proposeFile);  
38.         String contentRange = new StringBuffer("bytes ").append(  
39.                 new Long(pos).toString()).append("-").append(  
40.                 new Long(fSize - 1).toString()).append("/").append(  
41.                 new Long(fSize).toString()).toString();  
42.         response.setHeader("Content-Range", contentRange);  
43.         log.debug("Content-Range", contentRange);  
44.         inputStream.skip(pos);  
45.         byte[] buffer = new byte[5 * 1024];  
46.         int length = 0;  
47.         while ((length = inputStream.read(buffer, 0, buffer.length)) != -1) {  
48.             bufferOut.write(buffer, 0, length);  
49.         }  
50.         bufferOut.flush();  
51.         bufferOut.close();  
52.         out.close();  
53.         inputStream.close();  
54.     }  

追问

你这个好像是断点下载的，上传的有吗

Answer 2

我项目中用到的关键代码，断点下载文件：

URL url = new URL("http://f1.market.xiaomi.com/download/AppStore/0279e54e42c95454b29ac9628eccb1bfb5be22aeb/dian.zi.com.zidian.apk");

HttpURLConnection httpConnection = (HttpURLConnection) url.openConnection();

httpConnection.setRequestProperty("User-Agent", "NetFox");

httpConnection.setReadTimeout(60000);

//xxx表示你已下载的文件大小

httpConnection.setRequestProperty("RANGE", "bytes=" + xxx + "-");