Android 下載時，使用斷點續傳核心代碼

1. /**
   
2. * 斷點續傳
   
3. * @param url
   
4. */
   
5. private void duanDianXuChuan(final String url){
   
6. try {
   
7. Runnable r = new Runnable() {
   
8. @Override
   
9. public void run() {
   
10. getRemoteFile(url);
    
11. }
    
12. };
    
13. new Thread(r).start();
    
14. } catch (Exception e) {
    
15. e.printStackTrace();
    
16. }
    
17. }
    
18. /**
    
19. * 下載遠端文件
    
20. * @param urlString
    
21. */
    
22. private void getRemoteFile(String urlString){
    
23. try{
    
24. File file;
    
25. if(mCurSize == 0){
    
26. file = File.createTempFile(fileNa, fileEx);
    
27. currentTempFilePath = file.getAbsolutePath();
    
28. Log.e(「andy」,file.getName() + 」 has exists.」);
    
29. } else {
    
30. file = new File(currentTempFilePath);
    
31. FileInputStream fis = new FileInputStream(file);
    
32. mCurSize = fis.available();
    
33. Log.e(「andy」,file.getName() + 」 has 」 + mCurSize + 」 bytes.」);
    
34. }
    
35. URL url = new URL(urlString);
    
36. HttpURLConnection httpConnection = (HttpURLConnection) url
    
37. .openConnection();
    
38. httpConnection.setRequestProperty(「User-Agent」, 「NetFox」);
    
39. String sProperty = 「bytes=」 + mCurSize + 「-」;
    
40. httpConnection.setRequestProperty(「RANGE」, sProperty);
    
41. InputStream is = httpConnection.getInputStream();
    
42. Log.e(「andy」,」mTempFileName = 」 + mTempFileName);
    
43. /*將文件寫入暫存盤*/
    
44. FileOutputStream fos = new FileOutputStream(file, true);
    
45. byte buf[] = new byte[512];
    
46. do
    
47. {
    
48. int numread = is.read(buf);
    
49. if (numread <= 0)
    
50. {
    
51. mHandler.sendEmptyMessageDelayed(this.DOWNLOAD_FINISH, 0);
    
52. break;
    
53. }
    
54. mCurSize += numread;
    
55. mHandler.sendEmptyMessageDelayed(this.UPDATE_DOWNLOAD_PROGRESS, 0);
    
56. Log.e(「andy」,」current size = 」 + mCurSize);
    
57. fos.write(buf, 0, numread);
    
58. }while (mContinue);
    
59. /*打開文件進行安裝*/
    
60. if(mCurSize == mSize) {
    
61. mCurSize = 0;
    
62. openFile(file);
    
63. }
    
64. try
    
65. {
    
66. is.close();
    
67. }
    
68. catch (Exception ex)
    
69. {
    
70. Log.e(「andy」, 「error: 」 + ex.getMessage(), ex);
    
71. }
    
72. }catch(Exception e){
    
73. e.printStackTrace();
    
74. }
    
75. }
    
76. /**
    
77. * 獲得文件長度
    
78. * @param urlString
    
79. * @return
    
80. */
    
81. public long getFileSize(String urlString) {
    
82. int nFileLength = -1;
    
83. try {
    
84. URL url = new URL(urlString);
    
85. HttpURLConnection httpConnection = (HttpURLConnection) url
    
86. .openConnection();
    
87. httpConnection.setRequestProperty(「User-Agent」, 「NetFox」);
    
88. int responseCode = httpConnection.getResponseCode();
    
89. if (responseCode >= 400) {
    
90. return -2; // -2 represent access is error
    
91. }
    
92. String sHeader;
    
93. for (int i = 1;; i++) {
    
94. sHeader = httpConnection.getHeaderFieldKey(i);
    
95. if (sHeader != null) {
    
96. if (sHeader.equals(「content-length」)) {
    
97. nFileLength = Integer.parseInt(httpConnection
    
98. .getHeaderField(sHeader));
    
99. break;
    
100. }
     
101. } else
     
102. break;
     
103. }
     
104. } catch (IOException e) {
     
105. e.printStackTrace();
     
106. } catch (Exception e) {
     
107. e.printStackTrace();
     
108. }
     
109. return nFileLength;
     
110. }
     
111. /**
     
112. * 計算百分比
     
113. * @param p1
     
114. * @param p2
     
115. * @return
     
116. */
     
117. public static String percent(double p1, double p2) {
     
118. String str;
     
119. double p3 = p1 / p2;
     
120. NumberFormat nf = NumberFormat.getPercentInstance();
     
121. nf.setMinimumFractionDigits(2);
     
122. str = nf.format(p3);
     
123. Log.e(「andy」,」percentage = 」 + str);
     
124. return str;
     
125. }

複製代碼

這要如何用阿????