• DownloadTask.java

package services;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.RandomAccessFile;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.ArrayList;

import java.util.List;

import java.util.Timer;

import java.util.TimerTask;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import org.apache.http.HttpStatus;

import android.content.Context;

import android.content.Intent;

import android.os.Message;

import android.os.Messenger;

import db.ThreadDAO;

import db.ThreadDAOImpl;

import entities.FileInfo;

import entities.ThreadInfo;

public class DownloadTask {

private Context mContext = null;

private FileInfo mFileInfo = null;

private ThreadDAO mDao = null;

private int mFinished = 0;

public boolean isPause = false;

public DownloadTask(Context mContext, FileInfo mFileInfo) {

this.mContext = mContext;

this.mFileInfo = mFileInfo;

mDao = new ThreadDAOImpl(mContext);

}

public void download() {

List<ThreadInfo> threadInfos = mDao.getThreads(mFileInfo.getUrl());

ThreadInfo threadInfo = null;

if (threadInfos.size() == 0) {

threadInfo = new ThreadInfo(0, mFileInfo.getUrl(), 0, mFileInfo.getLength(), 0);

} else {

threadInfo = threadInfos.get(0);

}

new DownloadThread(threadInfo).start();

}

class DownloadThread extends Thread {

private ThreadInfo mThreadInfo = null;

public DownloadThread(ThreadInfo mThreadInfo) {

this.mThreadInfo = mThreadInfo;

}

public void run() {

if (!mDao.isExists(mThreadInfo.getUrl(), mThreadInfo.getId())) {

mDao.insertThread(mThreadInfo);

}

HttpURLConnection conn = null;

RandomAccessFile raf = null;

InputStream input = null;

try {

URL url = new URL(mThreadInfo.getUrl());

conn = (HttpURLConnection) url.openConnection();

conn.setConnectTimeout(3000);

conn.setRequestMethod("GET");

int start = mThreadInfo.getStart() + mThreadInfo.getFinished();

conn.setRequestProperty("Range", "bytes=" + start + "-" + mThreadInfo.getEnd());

File file = new File(DownloadService.DOWNLOAD_PATH, mFileInfo.getFileName());

raf = new RandomAccessFile(file, "rwd");

raf.seek(start);

Intent intent = new Intent(DownloadService.ACTION_UPDATE);

mFinished += mThreadInfo.getFinished();

if (conn.getResponseCode() == HttpStatus.SC_PARTIAL_CONTENT) {

input = conn.getInputStream();

byte[] buffer = new byte[1024 * 4];

int len = -1;

long time = System.currentTimeMillis();

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

raf.write(buffer, 0, len);

mFinished += len;

if (System.currentTimeMillis() - time > 500) {

time = System.currentTimeMillis();

intent.putExtra("finished", mFinished * 100 / mFileInfo.getLength());

mContext.sendBroadcast(intent);

}

if (isPause) {

mDao.updateThread(mThreadInfo.getUrl(), mThreadInfo.getId(), mFinished);

return;

}

}

mDao.deleteThread(mThreadInfo.getUrl(), mThreadInfo.getId());

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

raf.close();

conn.disconnect();

input.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}