小男孩‘自慰网亚洲一区二区,亚洲一级在线播放毛片,亚洲中文字幕av每天更新,黄aⅴ永久免费无码,91成人午夜在线精品,色网站免费在线观看,亚洲欧洲wwwww在线观看

搜索

QQ空間 QQ好友新浪微博微信

Java 下載支持?jǐn)帱c(diǎn)續(xù)傳

閃寧斯達(dá) 2011-12-30

展開(kāi)全文

[Java]代碼，服務(wù)器端實(shí)現(xiàn)

01
File file = new File(location);                         

02
                        if (file.exists()) {                                         

03
                            long p = 0; 

04
                            long fileLength; 

05
                            fileLength = file.length(); 

06
                              
07
                            // get file content 

08
                            InputStream ins = new FileInputStream(file); 

09
                            bis = new BufferedInputStream(ins);                             

10
                              
11
                            // tell the client to allow accept-ranges 

12
                            response.reset(); 

13
                            response.setHeader("Accept-Ranges", "bytes"); 

14
                              
15
                            // client requests a file block download start byte 

16
                            if (request.getHeader("Range") != null) {                                 

17
                                response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT); 

18
                                p = Long.parseLong(request.getHeader("Range") 

19
                                        .replaceAll("bytes=", "") 

20
                                        .replaceAll("-", "") 

21
                                        );                                 

22
                            } 

23
                            // support multi-threaded download 

24
                            // respone format: 

25
                            // Content-Length:[file size] - [client request start bytes from file block] 

26
                            response.setHeader("Content-Length", new Long(fileLength - p).toString()); 

27
                              
28
                            if (p != 0) { 

29
                                // 斷點(diǎn)開(kāi)始 

30
                                // 響應(yīng)的格式是: 

31
                                // Content-Range: bytes [文件塊的開(kāi)始字節(jié)]-[文件的總大小 - 1]/[文件的總大小] 

32
                                String contentRange = new StringBuffer("bytes ") 

33
                                        .append(new Long(p).toString()) 

34
                                        .append("-") 

35
                                        .append(new Long(fileLength - 1).toString()) 

36
                                        .append("/") 

37
                                        .append(new Long(fileLength).toString()) 

38
                                        .toString(); 

39
                                response.setHeader("Content-Range", contentRange); 

40
                                // pointer move to seek 

41
                                bis.skip(p); 

42
                            } 

43
                              
44
                            String fileName = file.getName(); 

45
                            response.addHeader("Content-Disposition", "attachment;filename=" + fileName); 

46
                                           
47
                            while ((size = bis.read(buf)) != -1) { 

48
                                response.getOutputStream().write(buf,0,size); 

49
                                response.getOutputStream().flush();                                 

50
                            } 

51
                            bis.close();

[代碼] 客戶端下載測(cè)試

01
public class TestDownload { 

02
  
03
    /** 

04
     * @param args 

05
     */

06
    public static void main(String[] args) { 

07
        // TODO Auto-generated method stub 

08
        HttpURLConnection httpURLConnection = null; 

09
        URL url = null; 

10
        BufferedInputStream bis = null; 

11
        byte[] buf = new byte[10240]; 

12
        int size = 0; 

13
        String fileName = "aaa.zip"; 

14
        String filePath = "C:\\Users\\Desktop"; 

15
        String remoteUrl = "http://127.0.0.1:8080/down.zip"; 

16
  
17
        // 檢查本地文件 

18
        RandomAccessFile rndFile = null; 

19
        File file = new File(filePath + "\\" + fileName); 

20
        long remoteFileSize = getRemoteFileSzie(remoteUrl); 

21
        long nPos = 0; 

22
         
23
        if (file.exists()) {                        

24
            long localFileSzie = file.length(); 

25
            if (localFileSzie < remoteFileSize) {                    

26
                System.out.println("文件續(xù)傳..."); 

27
                nPos = localFileSzie; 

28
            } else { 

29
                System.out.println("文件存在，重新下載..."); 

30
                file.delete(); 

31
                try { 

32
                    file.createNewFile(); 

33
                } catch (Exception e) { 

34
                    // TODO: handle exception 

35
                    e.printStackTrace(); 

36
                }    

37
            } 

38
             
39
        } else { 

40
            // 建立文件 

41
            try { 

42
                file.createNewFile(); 

43
            } catch (Exception e) { 

44
                // TODO: handle exception 

45
                e.printStackTrace(); 

46
            }            

47
        } 

48
         
49
        // 下載文件 

50
        try { 

51
            url = new URL(remoteUrl);        

52
            httpURLConnection = (HttpURLConnection)url.openConnection(); 

53
            // 設(shè)置User-Agent 

54
            httpURLConnection.setRequestProperty("User-Agent", "Net"); 

55
            // 設(shè)置續(xù)傳開(kāi)始 

56
            httpURLConnection.setRequestProperty("Range", "bytes=" + nPos + "-"); 

57
            // 獲取輸入流 

58
            bis = new BufferedInputStream(httpURLConnection.getInputStream());            

59
            rndFile = new RandomAccessFile(filePath + "\\" + fileName, "rw"); 

60
            rndFile.seek(nPos); 

61
            int i = 0; 

62
            while ((size = bis.read(buf)) != -1) { 

63
                //if (i > 500) break;                

64
                rndFile.write(buf, 0, size); 

65
                 
66
                i++; 

67
            } 

68
            System.out.println("i=" + i); 

69
            httpURLConnection.disconnect(); 

70
        } catch (Exception e) { 

71
            // TODO: handle exception 

72
            e.printStackTrace(); 

73
        } 

74
    } 

75
  
76
    public static long getRemoteFileSzie(String url) { 

77
        long size = 0; 

78
        try { 

79
            HttpURLConnection httpUrl = (HttpURLConnection)(new URL(url)).openConnection(); 

80
            size = httpUrl.getContentLength(); 

81
            httpUrl.disconnect();            

82
        } catch (Exception e) { 

83
            // TODO: handle exception 

84
            e.printStackTrace(); 

85
        } 

86
        return size; 

87
    } 

88
}

本站是提供個(gè)人知識(shí)管理的網(wǎng)絡(luò)存儲(chǔ)空間，所有內(nèi)容均由用戶發(fā)布，不代表本站觀點(diǎn)。請(qǐng)注意甄別內(nèi)容中的聯(lián)系方式、誘導(dǎo)購(gòu)買等信息，謹(jǐn)防詐騙。如發(fā)現(xiàn)有害或侵權(quán)內(nèi)容，請(qǐng)點(diǎn)擊一鍵舉報(bào)。

轉(zhuǎn)藏 分享

QQ空間 QQ好友新浪微博微信

獻(xiàn)花（0） +1

來(lái)自：閃寧斯達(dá) > 《java斷點(diǎn)續(xù)傳》

舉報(bào)/認(rèn)領(lǐng)