Android下使用TCP/IP协议实现断点上传
Android下使用TCP/IP协议实现断点上传
0.使用http协议是不能实现断点上传的,对于文件大小不一,与实际需求可以使用Socket断点上传
1.上传原理:Android客户端发送上传文件头字段给服务器,服务器判断文件是否在服务器上,文件是否有上传的记录,若是文件不存在,服务器则返回一个id(断点数据)通知客户端从什么位置开始上传,客户端开始从获得的位置开始上传文件
2.实例演示
(0)服务器端代码
- public class FileServer
- {
- //线程池
- private ExecutorService executorService;
- //监听端口
- private int port;
- //退出
- private boolean quit = false;
- private ServerSocket server;
- //存放断点数据
- private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();
- public FileServer(int port)
- {
- this.port = port;
- //创建线程池,池中具有(cpu个数*50)条线程
- executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 50);
- }
- /**
- * 退出
- */
- public void quit()
- {
- this.quit = true;
- try
- {
- server.close();
- }
- catch (IOException e)
- {
- e.printStackTrace();
- }
- }
- /**
- * 启动服务
- * @throws Exception
- */
- public void start() throws Exception
- {
- //实现端口监听
- server = new ServerSocket(port);
- while(!quit)
- {
- try
- {
- Socket socket = server.accept();
- //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
- executorService.execute(new SocketTask(socket));
- }
- catch (Exception e)
- {
- e.printStackTrace();
- }
- }
- }
- private final class SocketTask implements Runnable
- {
- private Socket socket = null;
- public SocketTask(Socket socket)
- {
- this.socket = socket;
- }
- @Override
- public void run()
- {
- try
- {
- System.out.println("accepted connection "+ socket.getInetAddress()+ ":"+ socket.getPort());
- //这里的输入流PushbackInputStream可以回退到之前的某个点开始进行读取
- PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());
- //得到客户端发来的第一行协议数据:Content-Length=143253434;filename=xxx.3gp;sourceid=
- //如果用户初次上传文件,sourceid的值为空。
- String head = StreamTool.readLine(inStream);
- System.out.println(head);
- if(head!=null)
- {
- //下面从协议数据中提取各项参数值
- String[] items = head.split(";");
- String filelength = items[0].substring(items[0].indexOf("=")+1);
- String filename = items[1].substring(items[1].indexOf("=")+1);
- String sourceid = items[2].substring(items[2].indexOf("=")+1);
- //生产资源id,如果需要唯一性,可以采用UUID
- long id = System.currentTimeMillis();
- FileLog log = null;
- if(sourceid!=null && !"".equals(sourceid))
- {
- id = Long.valueOf(sourceid);
- //查找上传的文件是否存在上传记录
- log = find(id);
- }
- File file = null;
- int position = 0;
- //如果上传的文件不存在上传记录,为文件添加跟踪记录
- if(log==null)
- {
- String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());
- //设置存放的位置与当前应用的位置有关
- File dir = new File("file/"+ path);
- if(!dir.exists()) dir.mkdirs();
- file = new File(dir, filename);
- //如果上传的文件发生重名,然后进行改名
- if(file.exists())
- {
- filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));
- file = new File(dir, filename);
- }
- save(id, file);
- }
- // 如果上传的文件存在上传记录,读取上次的断点位置
- else
- {
- //从上传记录中得到文件的路径
- file = new File(log.getPath());
- if(file.exists())
- {
- File logFile = new File(file.getParentFile(), file.getName()+".log");
- if(logFile.exists())
- {
- Properties properties = new Properties();
- properties.load(new FileInputStream(logFile));
- //读取断点位置
- position = Integer.valueOf(properties.getProperty("length"));
- }
- }
- }
- OutputStream outStream = socket.getOutputStream();
- String response = "sourceid="+ id+ ";position="+ position+ "/r/n";
- //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
- //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
- outStream.write(response.getBytes());
- //
- RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");
- //设置文件长度
- if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));
- //移动文件指定的位置开始写入数据
- fileOutStream.seek(position);
- byte[] buffer = new byte[1024];
- int len = -1;
- int length = position;
- //从输入流中读取数据写入到文件中
- while( (len=inStream.read(buffer)) != -1)
- {
- fileOutStream.write(buffer, 0, len);
- length += len;
- Properties properties = new Properties();
- properties.put("length", String.valueOf(length));
- FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));
- //实时记录文件的最后保存位置
- properties.store(logFile, null);
- logFile.close();
- }
- //如果长传长度等于实际长度则表示长传成功
- if(length==fileOutStream.length()) delete(id);
- fileOutStream.close();
- inStream.close();
- outStream.close();
- file = null;
- }
- }
- catch (Exception e)
- {
- e.printStackTrace();
- }
- finally
- {
- try
- {
- if(socket!=null && !socket.isClosed()) socket.close();
- }
- catch (IOException e)
- {
- e.printStackTrace();
- }
- }
- }
- }
- public FileLog find(Long sourceid)
- {
- return datas.get(sourceid);
- }
- //保存上传记录
- public void save(Long id, File saveFile)
- {
- //日后可以改成通过数据库存放
- datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));
- }
- //当文件上传完毕,删除记录
- public void delete(long sourceid)
- {
- if(datas.containsKey(sourceid)) datas.remove(sourceid);
- }
- private class FileLog{
- private Long id;
- private String path;
- public Long getId() {
- return id;
- }
- public void setId(Long id) {
- this.id = id;
- }
- public String getPath() {
- return path;
- }
- public void setPath(String path) {
- this.path = path;
- }
- public FileLog(Long id, String path) {
- this.id = id;
- this.path = path;
- }
- }
- }
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