断点续传和断点下载解析

 金诚   2017-02-24 21:40   311 人阅读  0 条评论

断点续传和断点下载都是用的RandomAccessFile, 它具有移动指定的文件大小的位置的功能seek 。

断点续传是由服务器给客户端一个已经上传的位置标记position,然后客户端再将文件指针移动到相应的position,通过输入流将文件剩余部分读出来传输给服务器

断点下载 是由客户端告诉服务器已经下载的大小,然后服务器会将指针移动到相应的position,继续读出,把文件返回给客户端。 当然为了下载的更快一下,也可以多线程下载,那么基本实现就是给每个线程分配固定的字节的文件,分别去读

 

首先是文件上传,这个要用到服务器

关键代码:

FileServer.java

 

Java代码  收藏代码
  1. import java.io.File;  
  2. import java.io.FileInputStream;  
  3. import java.io.FileOutputStream;  
  4. import java.io.IOException;  
  5. import java.io.InputStream;  
  6. import java.io.OutputStream;  
  7. import java.io.PushbackInputStream;  
  8. import java.io.RandomAccessFile;  
  9. import java.net.ServerSocket;  
  10. import java.net.Socket;  
  11. import java.text.SimpleDateFormat;  
  12. import java.util.Date;  
  13. import java.util.HashMap;  
  14. import java.util.Map;  
  15. import java.util.Properties;  
  16. import java.util.Set;  
  17. import java.util.concurrent.ExecutorService;  
  18. import java.util.concurrent.Executors;  
  19. import util.FileLogInfo;  
  20. import util.StreamTool;  
  21. public class FileServer {  
  22.      private ExecutorService executorService;//线程池  
  23.      private int port;//监听端口  
  24.      private boolean quit = false;//退出  
  25.      private ServerSocket server;  
  26.      private Map<Long, FileLogInfo> datas = new HashMap<Long, FileLogInfo>();//存放断点数据,以后改为数据库存放  
  27.      public FileServer(int port)  
  28.      {
  29.          this.port = port;  
  30.          //创建线程池,池中具有(cpu个数*50)条线程  
  31.          executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 50);  
  32.      }
  33.     /** 
  34.       * 退出 
  35.       */  
  36.      public void quit()  
  37.      {
  38.         this.quit = true;  
  39.         try   
  40.         {
  41.             server.close();
  42.         }catch (IOException e)   
  43.         {
  44.             e.printStackTrace();
  45.         }
  46.      }
  47.      /** 
  48.       * 启动服务 
  49.       * @throws Exception 
  50.       */  
  51.      public void start() throws Exception  
  52.      {
  53.          server = new ServerSocket(port);//实现端口监听  
  54.          while(!quit)  
  55.          {
  56.              try   
  57.              {
  58.                Socket socket = server.accept();
  59.                executorService.execute(new SocketTask(socket));//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  
  60.              }catch (Exception e)   
  61.              {
  62.                  e.printStackTrace();
  63.              }
  64.          }
  65.      }
  66.      private final class SocketTask implements Runnable  
  67.      {
  68.         private Socket socket = null;  
  69.         public SocketTask(Socket socket)   
  70.         {
  71.             this.socket = socket;  
  72.         }
  73.         @Override  
  74.         public void run()   
  75.         {
  76.             try   
  77.             {
  78.                 System.out.println("FileServer accepted connection "+ socket.getInetAddress()+ ":"+ socket.getPort());  
  79.                 //得到客户端发来的第一行协议数据:Content-Length=143253434;filename=xxx.3gp;sourceid=  
  80.                 //如果用户初次上传文件,sourceid的值为空。  
  81.                 InputStream inStream = socket.getInputStream();
  82.                 String head = StreamTool.readLine(inStream);
  83.                 System.out.println("FileServer head:"+head);  
  84.                 if(head!=null)  
  85.                 {
  86.                     //下面从协议数据中提取各项参数值  
  87.                     String[] items = head.split(";");  
  88.                     String filelength = items[0].substring(items[0].indexOf("=")+1);  
  89.                     String filename = items[1].substring(items[1].indexOf("=")+1);  
  90.                     String sourceid = items[2].substring(items[2].indexOf("=")+1);        
  91.                     //生成资源id,如果需要唯一性,可以采用UUID  
  92.                     long id = System.currentTimeMillis();  
  93.                     FileLogInfo log = null;  
  94.                     if(sourceid!=null && !"".equals(sourceid))  
  95.                     {
  96.                         id = Long.valueOf(sourceid);
  97.                         //查找上传的文件是否存在上传记录  
  98.                         log = find(id);
  99.                     }
  100.                     File file = null;  
  101.                     int position = 0;  
  102.                     //如果上传的文件不存在上传记录,为文件添加跟踪记录  
  103.                     if(log==null)  
  104.                     {
  105.                         //设置存放的位置与当前应用的位置有关  
  106.                         File dir = new File("c:/temp/");  
  107.                         if(!dir.exists()) dir.mkdirs();  
  108.                         file = new File(dir, filename);  
  109.                         //如果上传的文件发生重名,然后进行改名  
  110.                         if(file.exists())  
  111.                         {
  112.                             filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));  
  113.                             file = new File(dir, filename);  
  114.                         }
  115.                         save(id, file);
  116.                     }
  117.                     // 如果上传的文件存在上传记录,读取上次的断点位置  
  118.                     else  
  119.                     {
  120.                         System.out.println("FileServer have exits log not null");  
  121.                         //从上传记录中得到文件的路径  
  122.                         file = new File(log.getPath());  
  123.                         if(file.exists())  
  124.                         {
  125.                             File logFile = new File(file.getParentFile(), file.getName()+".log");  
  126.                             if(logFile.exists())  
  127.                             {
  128.                                 Properties properties = new Properties();  
  129.                                 properties.load(new FileInputStream(logFile));  
  130.                                 //读取断点位置  
  131.                                 position = Integer.valueOf(properties.getProperty("length"));  
  132.                             }
  133.                         }
  134.                     }
  135.                     //***************************上面是对协议头的处理,下面正式接收数据***************************************  
  136.                     //向客户端请求传输数据  
  137.                     OutputStream outStream = socket.getOutputStream();
  138.                     String response = "sourceid="+ id+ ";position="+ position+ "%";  
  139.                     //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=position  
  140.                     //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  
  141.                     outStream.write(response.getBytes());
  142.                     RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");  
  143.                     //设置文件长度  
  144.                     if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));  
  145.                     //移动文件指定的位置开始写入数据  
  146.                     fileOutStream.seek(position);
  147.                     byte[] buffer = new byte[1024];  
  148.                     int len = -1;  
  149.                     int length = position;  
  150.                     //从输入流中读取数据写入到文件中,并将已经传入的文件长度写入配置文件,实时记录文件的最后保存位置  
  151.                     while( (len=inStream.read(buffer)) != -1)  
  152.                     {
  153.                         fileOutStream.write(buffer, 0, len);  
  154.                         length += len;
  155.                         Properties properties = new Properties();  
  156.                         properties.put("length", String.valueOf(length));  
  157.                         FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));  
  158.                         //实时记录文件的最后保存位置  
  159.                         properties.store(logFile, null);  
  160.                         logFile.close();
  161.                     }
  162.                     //如果长传长度等于实际长度则表示长传成功  
  163.                     if(length==fileOutStream.length()){  
  164.                         delete(id);
  165.                     }
  166.                     fileOutStream.close();
  167.                     inStream.close();
  168.                     outStream.close();
  169.                     file = null;  
  170.                 }
  171.             }
  172.             catch (Exception e)   
  173.             {
  174.                 e.printStackTrace();
  175.             }
  176.             finally{  
  177.                 try  
  178.                 {
  179.                     if(socket!=null && !socket.isClosed()) socket.close();  
  180.                 }
  181.                 catch (IOException e)  
  182.                 {
  183.                     e.printStackTrace();
  184.                 }
  185.             }
  186.         }
  187.      }
  188.      /**
  189.       * 查找在记录中是否有sourceid的文件
  190.       * @param sourceid  
  191.       * @return  
  192.       */
  193.      public FileLogInfo find(Long sourceid)  
  194.      {
  195.          return datas.get(sourceid);  
  196.      }
  197.      /** 
  198.       * 保存上传记录,日后可以改成通过数据库存放 
  199.       * @param id 
  200.       * @param saveFile 
  201.       */  
  202.      public void save(Long id, File saveFile)  
  203.      {
  204.          System.out.println("save logfile "+id);  
  205.          datas.put(id, new FileLogInfo(id, saveFile.getAbsolutePath()));  
  206.      }
  207.      /** 
  208.       * 当文件上传完毕,删除记录 
  209.       * @param sourceid 
  210.       */  
  211.      public void delete(long sourceid)  
  212.      {
  213.          System.out.println("delete logfile "+sourceid);  
  214.          if(datas.containsKey(sourceid)) datas.remove(sourceid);  
  215.      }
  216. }

由于在上面的流程图中已经进行了详细的分析,我在这儿就不讲了,只是在存储数据的时候服务器没有用数据库去存储,这儿只是为了方便,所以要想测试断点上传,服务器是不能停的,否则数据就没有了,在以后改进的时候应该用数据库去存储数据。

文件上传客户端:

关键代码:

UploadActivity.java

 

Java代码  收藏代码
  1. package com.hao;  
  2. import java.io.File;  
  3. import java.util.List;  
  4. import com.hao.upload.UploadThread;  
  5. import com.hao.upload.UploadThread.UploadProgressListener;  
  6. import com.hao.util.ConstantValues;  
  7. import com.hao.util.FileBrowserActivity;  
  8. import android.app.Activity;  
  9. import android.app.Dialog;  
  10. import android.app.ProgressDialog;  
  11. import android.content.DialogInterface;  
  12. import android.content.Intent;  
  13. import android.content.res.Resources;  
  14. import android.net.Uri;  
  15. import android.os.Bundle;  
  16. import android.os.Environment;  
  17. import android.os.Handler;  
  18. import android.os.Message;  
  19. import android.util.Log;  
  20. import android.view.View;  
  21. import android.view.View.OnClickListener;  
  22. import android.widget.Button;  
  23. import android.widget.TextView;  
  24. import android.widget.Toast;  
  25. /** 
  26.  *  
  27.  * @author Administrator 
  28.  * 
  29.  */  
  30. public class UploadActivity extends Activity implements OnClickListener{  
  31.     private static final String TAG = "SiteFileFetchActivity";  
  32.     private Button download, upload, select_file;  
  33.     private TextView info;  
  34.     private static final int PROGRESS_DIALOG = 0;  
  35.     private ProgressDialog progressDialog;  
  36.     private UploadThread uploadThread;  
  37.     private String uploadFilePath = null;  
  38.     private String fileName;  
  39.     /** Called when the activity is first created. */  
  40.     @Override  
  41.     public void onCreate(Bundle savedInstanceState) {  
  42.         super.onCreate(savedInstanceState);  
  43.         setContentView(R.layout.upload);
  44.         initView();
  45.     }
  46.     private void initView(){  
  47.         download = (Button) findViewById(R.id.download);
  48.         download.setOnClickListener(this);  
  49.         upload = (Button) findViewById(R.id.upload);
  50.         upload.setOnClickListener(this);  
  51.         info = (TextView) findViewById(R.id.info);
  52.         select_file = (Button) findViewById(R.id.select_file);
  53.         select_file.setOnClickListener(this);  
  54.     }
  55.     @Override  
  56.     protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
  57.         // TODO Auto-generated method stub  
  58.         super.onActivityResult(requestCode, resultCode, data);  
  59.         if (resultCode == RESULT_OK) {  
  60.                   if (requestCode == 1) {  
  61.                            Uri uri = data.getData();    // 接收用户所选文件的路径  
  62.                            info.setText("select: " + uri); // 在界面上显示路径  
  63.                            uploadFilePath = uri.getPath();
  64.                            int last = uploadFilePath.lastIndexOf("/");  
  65.                            uploadFilePath = uri.getPath().substring(0, last+1);  
  66.                            fileName = uri.getLastPathSegment();
  67.                   }
  68.         }
  69.     }
  70.     protected Dialog onCreateDialog(int id) {  
  71.         switch(id) {  
  72.         case PROGRESS_DIALOG:  
  73.             progressDialog = new ProgressDialog(UploadActivity.this);  
  74.             progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
  75.             progressDialog.setButton("暂停", new DialogInterface.OnClickListener() {  
  76.                 @Override  
  77.                 public void onClick(DialogInterface dialog, int which) {  
  78.                     // TODO Auto-generated method stub  
  79.                     uploadThread.closeLink();
  80.                     dialog.dismiss();
  81.                 }
  82.             });
  83.             progressDialog.setMessage("正在上传...");  
  84.             progressDialog.setMax(100);  
  85.             return progressDialog;  
  86.         default:  
  87.             return null;  
  88.         }
  89.     }
  90.     /**  
  91.      * 使用Handler给创建他的线程发送消息,  
  92.      * 匿名内部类  
  93.      */    
  94.     private Handler handler = new Handler()    
  95.     {
  96.         @Override  
  97.         public void handleMessage(Message msg)     
  98.         {
  99.             //获得上传长度的进度    
  100.             int length = msg.getData().getInt("size");    
  101.             progressDialog.setProgress(length);
  102.             if(progressDialog.getProgress()==progressDialog.getMax())//上传成功    
  103.             {
  104.                 progressDialog.dismiss();
  105.                 Toast.makeText(UploadActivity.this, getResources().getString(R.string.upload_over), 1).show();    
  106.             }
  107.         }
  108.     };
  109.     @Override  
  110.     public void onClick(View v) {  
  111.         // TODO Auto-generated method stub  
  112.         Resources r = getResources();
  113.         switch(v.getId()){  
  114.             case R.id.select_file:  
  115.                 Intent intent = new Intent();  
  116.                 //设置起始目录和查找的类型  
  117.                 intent.setDataAndType(Uri.fromFile(new File("/sdcard")), "*/*");//"*/*"表示所有类型,设置起始文件夹和文件类型  
  118.                 intent.setClass(UploadActivity.this, FileBrowserActivity.class);  
  119.                 startActivityForResult(intent, 1);  
  120.                 break;  
  121.             case R.id.download:  
  122.                 startActivity(new Intent(UploadActivity.this, SmartDownloadActivity.class));  
  123.                 break;  
  124.             case R.id.upload:  
  125.                 if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))//判断SDCard是否存在    
  126.                 {
  127.                     if(uploadFilePath == null){  
  128.                         Toast.makeText(UploadActivity.this, "还没设置上传文件", 1).show();  
  129.                     }
  130.                     System.out.println("uploadFilePath:"+uploadFilePath+" "+fileName);  
  131.                     //取得SDCard的目录    
  132.                     File uploadFile = new File(new File(uploadFilePath), fileName);    
  133.                     Log.i(TAG, "filePath:"+uploadFile.toString());  
  134.                     if(uploadFile.exists())    
  135.                     {
  136.                         showDialog(PROGRESS_DIALOG);
  137.                         info.setText(uploadFile+" "+ConstantValues.HOST+":"+ConstantValues.PORT);  
  138.                         progressDialog.setMax((int) uploadFile.length());//设置长传文件的最大刻度  
  139.                         uploadThread = new UploadThread(UploadActivity.this, uploadFile, ConstantValues.HOST, ConstantValues.PORT);  
  140.                         uploadThread.setListener(new UploadProgressListener() {  
  141.                             @Override  
  142.                             public void onUploadSize(int size) {  
  143.                                 // TODO Auto-generated method stub  
  144.                                 Message msg = new Message();  
  145.                                 msg.getData().putInt("size", size);  
  146.                                 handler.sendMessage(msg);
  147.                             }
  148.                         });
  149.                         uploadThread.start();
  150.                     }
  151.                     else    
  152.                     {
  153.                         Toast.makeText(UploadActivity.this, "文件不存在", 1).show();    
  154.                     }
  155.                 }
  156.                 else    
  157.                 {
  158.                     Toast.makeText(UploadActivity.this, "SDCard不存在!", 1).show();    
  159.                 }
  160.                 break;  
  161.         }
  162.     }
  163. }

UploadThread.java

 

Java代码  收藏代码
  1. package com.hao.upload;  
  2. import java.io.File;  
  3. import java.io.IOException;  
  4. import java.io.InputStream;  
  5. import java.io.OutputStream;  
  6. import java.io.RandomAccessFile;  
  7. import java.net.Socket;  
  8. import android.content.Context;  
  9. import android.util.Log;  
  10. import com.hao.db.UploadLogService;  
  11. import com.hao.util.StreamTool;  
  12. public class UploadThread extends Thread {  
  13.     private static final String TAG = "UploadThread";  
  14.     /*需要上传文件的路径*/  
  15.     private File uploadFile;  
  16.     /*上传文件服务器的IP地址*/  
  17.     private String dstName;  
  18.     /*上传服务器端口号*/  
  19.     private int dstPort;  
  20.     /*上传socket链接*/  
  21.     private Socket socket;  
  22.     /*存储上传的数据库*/  
  23.     private UploadLogService logService;   
  24.     private UploadProgressListener listener;  
  25.     public UploadThread(Context context, File uploadFile, final String dstName,final int dstPort){  
  26.         this.uploadFile = uploadFile;  
  27.         this.dstName = dstName;  
  28.         this.dstPort = dstPort;  
  29.         logService = new UploadLogService(context);  
  30.     }
  31.     public void setListener(UploadProgressListener listener) {  
  32.         this.listener = listener;  
  33.     }
  34.     /** 
  35.      * 模拟断开连接 
  36.      */  
  37.     public void closeLink(){  
  38.         try{  
  39.             if(socket != null) socket.close();  
  40.         }catch(IOException e){  
  41.             e.printStackTrace();
  42.             Log.e(TAG, "close socket fail");  
  43.         }
  44.     }
  45.     @Override  
  46.     public void run() {  
  47.         // TODO Auto-generated method stub  
  48.         try {  
  49.             // 判断文件是否已有上传记录  
  50.             String souceid = logService.getBindId(uploadFile);
  51.             // 构造拼接协议  
  52.             String head = "Content-Length=" + uploadFile.length()  
  53.                     + ";filename=" + uploadFile.getName() + ";sourceid="  
  54.                     + (souceid == null ? "" : souceid) + "%";  
  55.             // 通过Socket取得输出流  
  56.             socket = new Socket(dstName, dstPort);  
  57.             OutputStream outStream = socket.getOutputStream();
  58.             outStream.write(head.getBytes());
  59.             Log.i(TAG, "write to outStream");  
  60.             InputStream inStream = socket.getInputStream();
  61.             // 获取到字符流的id与位置  
  62.             String response = StreamTool.readLine(inStream);
  63.             Log.i(TAG, "response:" + response);  
  64.             String[] items = response.split(";");  
  65.             String responseid = items[0].substring(items[0].indexOf("=") + 1);  
  66.             String position = items[1].substring(items[1].indexOf("=") + 1);  
  67.             // 代表原来没有上传过此文件,往数据库添加一条绑定记录  
  68.             if (souceid == null) {  
  69.                 logService.save(responseid, uploadFile);
  70.             }
  71.             RandomAccessFile fileOutStream = new RandomAccessFile(uploadFile, "r");  
  72.             // 查找上次传送的最终位置,并从这开始传送  
  73.             fileOutStream.seek(Integer.valueOf(position));
  74.             byte[] buffer = new byte[1024];  
  75.             int len = -1;  
  76.             // 初始化上传的数据长度  
  77.             int length = Integer.valueOf(position);  
  78.             while ((len = fileOutStream.read(buffer)) != -1) {  
  79.                 outStream.write(buffer, 0, len);  
  80.                 // 设置长传数据长度  
  81.                 length += len;
  82.                 listener.onUploadSize(length);
  83.             }
  84.             fileOutStream.close();
  85.             outStream.close();
  86.             inStream.close();
  87.             socket.close();
  88.             // 判断上传完则删除数据  
  89.             if (length == uploadFile.length())  
  90.                 logService.delete(uploadFile);
  91.         } catch (Exception e) {  
  92.             e.printStackTrace();
  93.         }
  94.     }
  95.     public interface UploadProgressListener{  
  96.         void onUploadSize(int size);  
  97.     }
  98. }

下面是多线程下载

SmartDownloadActivity.java

 

Java代码  收藏代码
  1. package com.hao;  
  2. import java.io.File;  
  3. import com.hao.R;  
  4. import com.hao.R.id;  
  5. import com.hao.R.layout;  
  6. import com.hao.download.SmartFileDownloader;  
  7. import com.hao.download.SmartFileDownloader.SmartDownloadProgressListener;  
  8. import com.hao.util.ConstantValues;  
  9. import android.app.Activity;  
  10. import android.os.Bundle;  
  11. import android.os.Environment;  
  12. import android.os.Handler;  
  13. import android.os.Message;  
  14. import android.view.View;  
  15. import android.widget.Button;  
  16. import android.widget.ProgressBar;  
  17. import android.widget.TextView;  
  18. import android.widget.Toast;  
  19. /** 
  20.  *  
  21.  * @author Administrator 
  22.  *  
  23.  */  
  24. public class SmartDownloadActivity extends Activity {  
  25.     private ProgressBar downloadbar;  
  26.     private TextView resultView;  
  27.     private String path = ConstantValues.DOWNLOAD_URL;  
  28.     SmartFileDownloader loader;
  29.     private Handler handler = new Handler() {  
  30.         @Override  
  31.         // 信息  
  32.         public void handleMessage(Message msg) {  
  33.             switch (msg.what) {  
  34.             case 1:  
  35.                 int size = msg.getData().getInt("size");  
  36.                 downloadbar.setProgress(size);
  37.                 float result = (float) downloadbar.getProgress() / (float) downloadbar.getMax();  
  38.                 int p = (int) (result * 100);  
  39.                 resultView.setText(p + "%");  
  40.                 if (downloadbar.getProgress() == downloadbar.getMax())  
  41.                     Toast.makeText(SmartDownloadActivity.this, "下载成功", 1).show();  
  42.                 break;  
  43.             case -1:  
  44.                 Toast.makeText(SmartDownloadActivity.this, msg.getData().getString("error"), 1).show();  
  45.                 break;  
  46.             }
  47.         }
  48.     };
  49.     public void onCreate(Bundle savedInstanceState) {  
  50.         super.onCreate(savedInstanceState);  
  51.         setContentView(R.layout.download);
  52.         Button button = (Button) this.findViewById(R.id.button);  
  53.         Button closeConn = (Button) findViewById(R.id.closeConn);
  54.         closeConn.setOnClickListener(new View.OnClickListener() {  
  55.             @Override  
  56.             public void onClick(View v) {  
  57.                 // TODO Auto-generated method stub  
  58.                 if(loader != null){  
  59.                     finish();
  60.                 }else{  
  61.                     Toast.makeText(SmartDownloadActivity.this, "还没有开始下载,不能暂停", 1).show();  
  62.                 }
  63.             }
  64.         });
  65.         downloadbar = (ProgressBar) this.findViewById(R.id.downloadbar);  
  66.         resultView = (TextView) this.findViewById(R.id.result);  
  67.         resultView.setText(path);
  68.         button.setOnClickListener(new View.OnClickListener() {  
  69.             @Override  
  70.             public void onClick(View v) {  
  71.                 if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {  
  72.                     download(path, ConstantValues.FILE_PATH);
  73.                 } else {  
  74.                     Toast.makeText(SmartDownloadActivity.this, "没有SDCard", 1).show();  
  75.                 }
  76.             }
  77.         });
  78.     }
  79.     // 对于UI控件的更新只能由主线程(UI线程)负责,如果在非UI线程更新UI控件,更新的结果不会反映在屏幕上,某些控件还会出错  
  80.     private void download(final String path, final File dir) {  
  81.         new Thread(new Runnable() {  
  82.             @Override  
  83.             public void run() {  
  84.                 try {  
  85.                     loader = new SmartFileDownloader(SmartDownloadActivity.this, path, dir, 3);  
  86.                     int length = loader.getFileSize();// 获取文件的长度  
  87.                     downloadbar.setMax(length);
  88.                     loader.download(new SmartDownloadProgressListener() {  
  89.                         @Override  
  90.                         public void onDownloadSize(int size) {// 可以实时得到文件下载的长度  
  91.                             Message msg = new Message();  
  92.                             msg.what = 1;  
  93.                             msg.getData().putInt("size", size);  
  94.                             handler.sendMessage(msg);
  95.                         }
  96.                     });
  97.                 } catch (Exception e) {  
  98.                     Message msg = new Message();// 信息提示  
  99.                     msg.what = -1;  
  100.                     msg.getData().putString("error", "下载失败");// 如果下载错误,显示提示失败!  
  101.                     handler.sendMessage(msg);
  102.                 }
  103.             }
  104.         }).start();// 开始  
  105.     }
  106. }

这个单个的下载线程

SmartDownloadThread.java

 

Java代码  收藏代码
  1. package com.hao.download;  
  2. import java.io.File;  
  3. import java.io.InputStream;  
  4. import java.io.RandomAccessFile;  
  5. import java.net.HttpURLConnection;  
  6. import java.net.URL;  
  7. import android.util.Log;  
  8. /** 
  9.  * 线程下载 
  10.  * @author Administrator 
  11.  *  
  12.  */  
  13. public class SmartDownloadThread extends Thread {  
  14.     private static final String TAG = "SmartDownloadThread";  
  15.     private File saveFile;  
  16.     private URL downUrl;  
  17.     private int block;  
  18.     /*  *下载开始位置 */  
  19.     private int threadId = -1;  
  20.     private int downLength;  
  21.     private boolean finish = false;  
  22.     private SmartFileDownloader downloader;  
  23.     public SmartDownloadThread(SmartFileDownloader downloader, URL downUrl,  
  24.             File saveFile, int block, int downLength, int threadId) {  
  25.         this.downUrl = downUrl;  
  26.         this.saveFile = saveFile;  
  27.         this.block = block;  
  28.         this.downloader = downloader;  
  29.         this.threadId = threadId;  
  30.         this.downLength = downLength;  
  31.     }
  32.     @Override  
  33.     public void run() {  
  34.         if (downLength < block) {// 未下载完成  
  35.             try {  
  36.                 HttpURLConnection http = (HttpURLConnection) downUrl
  37.                         .openConnection();
  38.                 http.setConnectTimeout(5 * 1000);  
  39.                 http.setRequestMethod("GET");  
  40.                 http.setRequestProperty("Accept","image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");  
  41.                 http.setRequestProperty("Accept-Language", "zh-CN");  
  42.                 http.setRequestProperty("Referer", downUrl.toString());  
  43.                 http.setRequestProperty("Charset", "UTF-8");  
  44.                 int startPos = block * (threadId - 1) + downLength;// 开始位置  
  45.                 int endPos = block * threadId - 1;// 结束位置  
  46.                 http.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);// 设置获取实体数据的范围  
  47.                 http.setRequestProperty("User-Agent","Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");  
  48.                 http.setRequestProperty("Connection", "Keep-Alive");  
  49.                 InputStream inStream = http.getInputStream();
  50.                 byte[] buffer = new byte[1024];  
  51.                 int offset = 0;  
  52.                 print("Thread " + this.threadId + " start download from position " + startPos);  
  53.                 RandomAccessFile threadfile = new RandomAccessFile(this.saveFile, "rwd");  
  54.                 threadfile.seek(startPos);
  55.                 while ((offset = inStream.read(buffer, 0, 1024)) != -1) {  
  56.                     threadfile.write(buffer, 0, offset);  
  57.                     downLength += offset;
  58.                     downloader.update(this.threadId, downLength);  
  59.                     downloader.saveLogFile();
  60.                     downloader.append(offset);
  61.                 }
  62.                 threadfile.close();
  63.                 inStream.close();
  64.                 print("Thread " + this.threadId + " download finish");  
  65.                 this.finish = true;  
  66.             } catch (Exception e) {  
  67.                 this.downLength = -1;  
  68.                 print("Thread " + this.threadId + ":" + e);  
  69.             }
  70.         }
  71.     }
  72.     private static void print(String msg) {  
  73.         Log.i(TAG, msg);
  74.     }
  75.     /**
  76.      * 下载是否完成
  77.      * @return  
  78.      */
  79.     public boolean isFinish() {  
  80.         return finish;  
  81.     }
  82.     /** 
  83.      * 已经下载的内容大小 
  84.      * @return 如果返回值为-1,代表下载失败 
  85.      */  
  86.     public long getDownLength() {  
  87.         return downLength;  
  88.     }
  89. }

总得下载线程

SmartFileDownloader.java

 

Java代码  收藏代码
    1. package com.hao.download;  
    2. import java.io.File;  
    3. import java.io.RandomAccessFile;  
    4. import java.net.HttpURLConnection;  
    5. import java.net.URL;  
    6. import java.util.LinkedHashMap;  
    7. import java.util.Map;  
    8. import java.util.UUID;  
    9. import java.util.concurrent.ConcurrentHashMap;  
    10. import java.util.regex.Matcher;  
    11. import java.util.regex.Pattern;  
    12. import com.hao.db.DownloadFileService;  
    13. import android.content.Context;  
    14. import android.util.Log;  
    15. /** 
    16.  * 文件下载主程序 
    17.  * @author Administrator 
    18.  *  
    19.  */  
    20. public class SmartFileDownloader {  
    21.     private static final String TAG = "SmartFileDownloader";  
    22.     private Context context;  
    23.     private DownloadFileService fileService;  
    24.     /* 已下载文件长度 */  
    25.     private int downloadSize = 0;  
    26.     /* 原始文件长度 */  
    27.     private int fileSize = 0;  
    28.     /*原始文件名*/  
    29.     private String fileName;  
    30.     /* 线程数 */  
    31.     private SmartDownloadThread[] threads;  
    32.     /* 本地保存文件 */  
    33.     private File saveFile;  
    34.     /* 缓存各线程下载的长度 */  
    35.     private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();  
    36.     /* 每条线程下载的长度 */  
    37.     private int block;  
    38.     /* 下载路径 */  
    39.     private String downloadUrl;  
    40.     /** 
    41.      * 获取文件名 
    42.      */  
    43.     public String getFileName(){  
    44.         return this.fileName;  
    45.     }
    46.     /** 
    47.      * 获取线程数 
    48.      */  
    49.     public int getThreadSize() {  
    50.         return threads.length;  
    51.     }
    52.     /** 
    53.      * 获取文件大小 
    54.      * @return 
    55.      */  
    56.     public int getFileSize() {  
    57.         return fileSize;  
    58.     }
    59.     /** 
    60.      * 累计已下载大小 
    61.      * @param size 
    62.      */  
    63.     protected synchronized void append(int size) {  
    64.         downloadSize += size;
    65.     }
    66.     /** 
    67.      * 更新指定线程最后下载的位置 
    68.      * @param threadId 线程id 
    69.      * @param pos 最后下载的位置 
    70.      */  
    71.     protected void update(int threadId, int pos) {  
    72.         this.data.put(threadId, pos);  
    73.     }
    74.     /** 
    75.      * 保存记录文件 
    76.      */  
    77.     protected synchronized void saveLogFile() {  
    78.         this.fileService.update(this.downloadUrl, this.data);  
    79.     }
    80.     /** 
    81.      * 构建文件下载器 
    82.      * @param downloadUrl 下载路径 
    83.      * @param fileSaveDir 文件保存目录 
    84.      * @param threadNum 下载线程数 
    85.      */  
    86.     public SmartFileDownloader(Context context, String downloadUrl,  
    87.             File fileSaveDir, int threadNum) {  
    88.         try {  
    89.             this.context = context;  
    90.             this.downloadUrl = downloadUrl;  
    91.             fileService = new DownloadFileService(this.context);  
    92.             URL url = new URL(this.downloadUrl);  
    93.             if (!fileSaveDir.exists()) fileSaveDir.mkdirs();  
    94.             this.threads = new SmartDownloadThread[threadNum];  
    95.             HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    96.             conn.setConnectTimeout(5 * 1000);  
    97.             conn.setRequestMethod("GET");  
    98.             conn.setRequestProperty("Accept", "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");  
    99.             conn.setRequestProperty("Accept-Language", "zh-CN");  
    100.             conn.setRequestProperty("Referer", downloadUrl);  
    101.             conn.setRequestProperty("Charset", "UTF-8");  
    102.             conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");  
    103.             conn.setRequestProperty("Connection", "Keep-Alive");  
    104.             conn.connect();
    105.             printResponseHeader(conn);
    106.             if (conn.getResponseCode() == 200) {  
    107.                 this.fileSize = conn.getContentLength();// 根据响应获取文件大小  
    108.                 if (this.fileSize <= 0)  
    109.                     throw new RuntimeException("Unkown file size ");  
    110.                 fileName = getFileName(conn);
    111.                 this.saveFile = new File(fileSaveDir, fileName);/* 保存文件 */  
    112.                 Map<Integer, Integer> logdata = fileService.getData(downloadUrl);
    113.                 if (logdata.size() > 0) {  
    114.                     for (Map.Entry<Integer, Integer> entry : logdata.entrySet())  
    115.                         data.put(entry.getKey(), entry.getValue());
    116.                 }
    117.                 //划分每个线程下载文件长度  
    118.                 this.block = (this.fileSize % this.threads.length) == 0 ? this.fileSize / this.threads.length  
    119.                         : this.fileSize / this.threads.length + 1;  
    120.                 if (this.data.size() == this.threads.length) {  
    121.                     for (int i = 0; i < this.threads.length; i++) {  
    122.                         this.downloadSize += this.data.get(i + 1);  
    123.                     }
    124.                     print("已经下载的长度" + this.downloadSize);  
    125.                 }
    126.             } else {  
    127.                 throw new RuntimeException("server no response ");  
    128.             }
    129.         } catch (Exception e) {  
    130.             print(e.toString());
    131.             throw new RuntimeException("don't connection this url");  
    132.         }
    133.     }
    134.     /** 
    135.      * 获取文件名 
    136.      */  
    137.     private String getFileName(HttpURLConnection conn) {  
    138.         String filename = this.downloadUrl.substring(this.downloadUrl.lastIndexOf('/') + 1);//链接的最后一个/就是文件名  
    139.         if (filename == null || "".equals(filename.trim())) {// 如果获取不到文件名称  
    140.             for (int i = 0;; i++) {  
    141.                 String mine = conn.getHeaderField(i);
    142.                 print("ConnHeader:"+mine+" ");  
    143.                 if (mine == null)  
    144.                     break;  
    145.                 if ("content-disposition".equals(conn.getHeaderFieldKey(i).toLowerCase())) {  
    146.                     Matcher m = Pattern.compile(".*filename=(.*)").matcher(mine.toLowerCase());  
    147.                     if (m.find())  
    148.                         return m.group(1);  
    149.                 }
    150.             }
    151.             filename = UUID.randomUUID() + ".tmp";// 默认取一个文件名  
    152.         }
    153.         return filename;  
    154.     }
    155.     /** 
    156.      * 开始下载文件 
    157.      *  
    158.      * @param listener 
    159.      *            监听下载数量的变化,如果不需要了解实时下载的数量,可以设置为null 
    160.      * @return 已下载文件大小 
    161.      * @throws Exception 
    162.      */  
    163.     public int download(SmartDownloadProgressListener listener)  
    164.             throws Exception {  
    165.         try {  
    166.             RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");  
    167.             if (this.fileSize > 0)  
    168.                 randOut.setLength(this.fileSize);  
    169.             randOut.close();
    170.             URL url = new URL(this.downloadUrl);  
    171.             if (this.data.size() != this.threads.length) {  
    172.                 this.data.clear();// 清除数据  
    173.                 for (int i = 0; i < this.threads.length; i++) {  
    174.                     this.data.put(i + 1, 0);  
    175.                 }
    176.             }
    177.             for (int i = 0; i < this.threads.length; i++) {  
    178.                 int downLength = this.data.get(i + 1);  
    179.                 if (downLength < this.block && this.downloadSize < this.fileSize) { // 该线程未完成下载时,继续下载  
    180.                     this.threads[i] = new SmartDownloadThread(this, url,  
    181.                             this.saveFile, this.block, this.data.get(i + 1), i + 1);  
    182.                     this.threads[i].setPriority(7);  
    183.                     this.threads[i].start();  
    184.                 } else {  
    185.                     this.threads[i] = null;  
    186.                 }
    187.             }
    188.             this.fileService.save(this.downloadUrl, this.data);  
    189.             boolean notFinish = true;// 下载未完成  
    190.             while (notFinish) {// 循环判断是否下载完毕  
    191.                 Thread.sleep(900);  
    192.                 notFinish = false;// 假定下载完成  
    193.                 for (int i = 0; i < this.threads.length; i++) {  
    194.                     if (this.threads[i] != null && !this.threads[i].isFinish()) {  
    195.                         notFinish = true;// 下载没有完成  
    196.                         if (this.threads[i].getDownLength() == -1) {// 如果下载失败,再重新下载  
    197.                             this.threads[i] = new SmartDownloadThread(this,  
    198.                                     url, this.saveFile, this.block, this.data.get(i + 1), i + 1);  
    199.                             this.threads[i].setPriority(7);  
    200.                             this.threads[i].start();  
    201.                         }
    202.                     }
    203.                 }
    204.                 if (listener != null)  
    205.                     listener.onDownloadSize(this.downloadSize);  
    206.             }
    207.             fileService.delete(this.downloadUrl);  
    208.         } catch (Exception e) {  
    209.             print(e.toString());
    210.             throw new Exception("file download fail");  
    211.         }
    212.         return this.downloadSize;  
    213.     }
    214.     /** 
    215.      * 获取Http响应头字段 
    216.      *  
    217.      * @param http 
    218.      * @return 
    219.      */  
    220.     public static Map<String, String> getHttpResponseHeader(  
    221.             HttpURLConnection http) {
    222.         Map<String, String> header = new LinkedHashMap<String, String>();  
    223.         for (int i = 0;; i++) {  
    224.             String mine = http.getHeaderField(i);
    225.             if (mine == null)  
    226.                 break;  
    227.             header.put(http.getHeaderFieldKey(i), mine);
    228.         }
    229.         return header;  
    230.     }
    231.     /** 
    232.      * 打印Http头字段 
    233.      *  
    234.      * @param http 
    235.      */  
    236.     public static void printResponseHeader(HttpURLConnection http) {  
    237.         Map<String, String> header = getHttpResponseHeader(http);
    238.         for (Map.Entry<String, String> entry : header.entrySet()) {  
    239.             String key = entry.getKey() != null ? entry.getKey() + ":" : "";  
    240.             print(key + entry.getValue());
    241.         }
    242.     }
    243.     // 打印日志  
    244.     private static void print(String msg) {  
    245.         Log.i(TAG, msg);
    246.     }
    247.     public interface SmartDownloadProgressListener {  
    248.         public void onDownloadSize(int size);  
    249.     }
    250. }
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