Android应用开发之使用Socket进行大文件断点上传续传

在Android中上传文件可以采用HTTP方式，也可以采用Socket方式，但是HTTP方式不能上传大文件，这里介绍一种通过Socket方式来进行断点续传的方式，服务端会记录下文件的上传进度，当某一次上传过程意外终止后，下一次可以继续上传，这里用到的其实还是J2SE里的知识。
这个上传程序的原理是：客户端第一次上传时向服务端发送“Content-Length=35;filename=WinRAR_3.90_SC.exe;sourceid=“这种格式的字符串，服务端收到后会查找该文件是否有上传记录，如果有就返回已经上传的位置，否则返回新生成的sourceid以及position为0，类似”sourceid=2324838389;position=0“这样的字符串，客户端收到返回后的字符串后再从指定的位置开始上传文件。

首先是服务端代码：

SocketServer.java

1.package com.android.socket.server;

2.

3.import java.io.File;

4.import java.io.FileInputStream;
5.import java.io.FileOutputStream;
6.import java.io.IOException;
7.import java.io.OutputStream;

8.import java.io.PushbackInputStream;

9.import java.io.RandomAccessFile;

10.import java.net.ServerSocket;

11.import java.net.Socket;
12.import java.text.SimpleDateFormat;
13.import java.util.Date;

14.import java.util.HashMap;
15.import java.util.Map;

16.import java.util.Properties;

17.import java.util.concurrent.ExecutorService;

18.import java.util.concurrent.Executors;

19.

20.import com.android.socket.utils.StreamTool;

21.

22.public class SocketServer {

23. private ExecutorService executorService;// 线程池

24. private ServerSocket ss = null;

25. private int port;// 监听端口

26. private boolean quit;// 是否退出

27. private Map datas = new HashMap();// 存放断点数据，最好改为数据库存放

28.

29. public SocketServer(int port) {

30. this.port = port;

31. // 初始化线程池

32. executorService = Executors.newFixedThreadPool(Runtime.getRuntime()

33. .availableProcessors() * 50);

34. }

35.

36. // 启动服务

37. public void start() throws Exception {

38. ss = new ServerSocket(port);

39. while (!quit) {

40. Socket socket = ss.accept();// www.linuxidc.com接受客户端的请求

41. // 为支持多用户并发访问，采用线程池管理每一个用户的连接请求

42. executorService.execute(new SocketTask(socket));// 启动一个线程来处理请求

43. }

44. }

45.

46. // 退出

47. public void quit() {

48. this.quit = true;

49. try {

50. ss.close();

51. } catch (IOException e) {

52. e.printStackTrace();

53. }

54. }

55.

56. public static void main(String[] args) throws Exception {

57. SocketServer server = new SocketServer(8787);

58. server.start();

59. }

60.

61. private class SocketTask implements Runnable {

62. private Socket socket;
63.

64. public SocketTask(Socket socket) {

65. this.socket = socket;

66. }

67.

68. @Override

69. public void run() {

70. try {

71. System.out.println("accepted connenction from "

72. + socket.getInetAddress() + " @ " + socket.getPort());

73. PushbackInputStream inStream = new PushbackInputStream(

74. socket.getInputStream());

75. // 得到客户端发来的第一行协议数据：Content-Length=143253434;filename=xxx.3gp;sourceid=

76. // 如果用户初次上传文件，sourceid的值为空。

77. String head = StreamTool.readLine(inStream);

78. System.out.println(head);

79. if (head != null) {

80. // 下面从协议数据中读取各种参数值

81. String[] items = head.split(";");

82. String filelength = items[0].substring(items[0].indexOf("=") + 1);

83. String filename = items[1].substring(items[1].indexOf("=") + 1);

84. String sourceid = items[2].substring(items[2].indexOf("=") + 1);

85. Long id = System.currentTimeMillis();

86. FileLog log = null;

87. if (null != sourceid && !"".equals(sourceid)) {

88. id = Long.valueOf(sourceid);

89. log = find(id);//查找上传的文件是否存在上传记录

90. }

91. File file = null;

92. int position = 0;

93. if(log==null){//如果上传的文件不存在上传记录,为文件添加跟踪记录

94. String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());

95. File dir = new File("file/"+ path);

96. if(!dir.exists()) dir.mkdirs();

97. file = new File(dir, filename);

98. if(file.exists()){//如果上传的文件发生重名，然后进行改名

99. filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));

100. file = new File(dir, filename);

101. }

102. save(id, file);

103. }else{// 如果上传的文件存在上传记录,读取上次的断点位置

104. file = new File(log.getPath());//从上传记录中得到文件的路径

105. if(file.exists()){
106. File logFile = new File(file.getParentFile(), file.getName()+".log");

107. if(logFile.exists()){

108. Properties properties = new Properties();

109. properties.load(new FileInputStream(logFile));

110. position = Integer.valueOf(properties.getProperty("length"));//读取断点位置

111. }

112. }

113. }

114.

115. OutputStream outStream = socket.getOutputStream();

116. String response = "sourceid="+ id+ ";position="+ position+ "rn";

117. //服务器收到客户端的请求信息后，给客户端返回响应信息：sourceid=1274773833264;position=0

118. //sourceid由服务生成，唯一标识上传的文件，position指示客户端从文件的什么位置开始上传

119. outStream.write(response.getBytes());

120.

121. RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");

122. if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));//设置文件长度

123. fileOutStream.seek(position);//移动文件指定的位置开始写入数据

124. byte[] buffer = new byte[1024];

125. int len = -1;

126. int length = position;

127. while( (len=inStream.read(buffer)) != -1){//从输入流中读取数据写入到文件中

128. fileOutStream.write(buffer, 0, len);

129. length += len;

130. Properties properties = new Properties();

131. properties.put("length", String.valueOf(length));

132. FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));

133. properties.store(logFile, null);//实时记录文件的最后保存位置

134. logFile.close();

135. }

136. if(length==fileOutStream.length()) delete(id);

137. fileOutStream.close();

138. inStream.close();

139. outStream.close();

140. file = null;

141. }

142. } catch (Exception e) {

143. e.printStackTrace();

144. } finally {

145. try {

146. if(socket != null && !socket.isClosed()) socket.close();

147. } catch (IOException e) {}

148. }

149. }

150.

151. }

152.

153. public FileLog find(Long sourceid) {

154. return datas.get(sourceid);

155. }

156.

157. // 保存上传记录

158. public void save(Long id, File saveFile) {

159. // 日后可以改成通过数据库存放

160. datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));

161. }

162.

163. // 当文件上传完毕，删除记录

164. public void delete(long sourceid) {

165. if (datas.containsKey(sourceid))

166. datas.remove(sourceid);

167. }

168.

169. private class FileLog {

170. private Long id;

171. private String path;

172.

173. public FileLog(Long id, String path) {

174. super();

175. this.id = id;

176. this.path = path;

177. }

178.

179. public Long getId() {

180. return id;

181. }

182.

183. public void setId(Long id) {

184. this.id = id;

185. }

186.

187. public String getPath() {

188. return path;

189. }

190.

191. public void setPath(String path) {

192. this.path = path;

193. }

194.

195. }

196.}

ServerWindow.java

1.package com.android.socket.server;

2.

3.import java.awt.BorderLayout;

4.import java.awt.Frame;

5.import java.awt.Label;

6.import java.awt.event.WindowEvent;

7.import java.awt.event.WindowListener;

8.

9.public class ServerWindow extends Frame{

10. private SocketServer server;

11. private Label label;

12.

13. public ServerWindow(String title){

14. super(title);

15. server = new SocketServer(8787);

16. label = new Label();

17. add(label, BorderLayout.PAGE_START);

18. label.setText("服务器已经启动www.linuxidc.com");

19. this.addWindowListener(new WindowListener() {

20. @Override

21. public void windowOpened(WindowEvent e) {

22. new Thread(new Runnable() {

23. @Override

24. public void run() {

25. try {

26. server.start();

27. } catch (Exception e) {

28. e.printStackTrace();

29. }

30. }

31. }).start();

32. }

33.

34. @Override

35. public void windowIconified(WindowEvent e) {

36. }

37.

38. @Override

39. public void windowDeiconified(WindowEvent e) {

40. }

41.

42. @Override

43. public void windowDeactivated(WindowEvent e) {

44. }

45.

46. @Override

47. public void windowClosing(WindowEvent e) {

48. server.quit();

49. System.exit(0);

50. }

51.

52. @Override

53. public void windowClosed(WindowEvent e) {

54. }

55.

56. @Override

57. public void windowActivated(WindowEvent e) {

58. }

59. });

60. }

61. /**
62. * @param args
63. /

64. public static void main(String[] args) {

65. ServerWindow window = new ServerWindow("文件上传服务端");

66. window.setSize(300, 300);

67. window.setVisible(true);

68. }

69.

70.}

工具类StreamTool.java
1.package com.android.socket.utils;

2.

3.import java.io.ByteArrayOutputStream;

4.import java.io.File; 5.import java.io.FileOutputStream;

6.import java.io.IOException;

7.import java.io.InputStream;

8.import java.io.PushbackInputStream;

9.

10.public class StreamTool {

11.

12. public static void save(File file, byte[] data) throws Exception {

13. FileOutputStream outStream = new FileOutputStream(file);

14. outStream.write(data);

15. outStream.close();

16. }

17.

18. public static String readLine(PushbackInputStream in) throws IOException {

19. char buf[] = new char[128];

20. int room = buf.length;

21. int offset = 0;

22. int c;

23.loop: while (true) {

24. switch (c = in.read()) {

25. case -1:

26. case ‘n‘:

27. break loop;

28. case ‘r‘:

29. int c2 = in.read();

30. if ((c2 != ‘n‘) && (c2 != -1)) in.unread(c2);

31. break loop;

32. default:

33. if (--room < 0) {

34. char[] lineBuffer = buf;

35. buf = new char[offset + 128];

36. room = buf.length - offset - 1;

37. System.arraycopy(lineBuffer, 0, buf, 0, offset);

38.

39. }

40. buf[offset++] = (char) c;

41. break; 42. }

43. }

44. if ((c == -1) && (offset == 0)) return null;

45. return String.copyValueOf(buf, 0, offset);

46. }

47.

48. /*
49. * 读取流
50. * @param inStream
51. * @return 字节数组
52. * @throws Exception
53. */

54. public static byte[] readStream(InputStream inStream) throws Exception{

55. ByteArrayOutputStream outSteam = new ByteArrayOutputStream();

56. byte[] buffer = new byte[1024];

57. int len = -1;

58. while( (len=inStream.read(buffer)) != -1){

59. outSteam.write(buffer, 0, len);

60. }

61. outSteam.close();

62. inStream.close();

63. return outSteam.toByteArray();

64. }

65.}

Android客户端代码：

Android应用开发之使用Socket进行大文件断点上传续传,,5-wow.com