package com.bbk.lling.multitaskdownload.downloador;import android.content.Context;import android.content.Intent;import android.os.AsyncTask;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.text.TextUtils;import android.util.Log;import android.widget.Toast;import com.bbk.lling.multitaskdownload.beans.AppContent;import com.bbk.lling.multitaskdownload.beans.DownloadInfo;import com.bbk.lling.multitaskdownload.db.DownloadFileDAO;import com.bbk.lling.multitaskdownload.db.DownloadInfoDAO;import com.bbk.lling.multitaskdownload.utils.DownloadUtils;import org.apache.http.HttpResponse;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.impl.client.DefaultHttpClient;import java.util.ArrayList;import java.util.List;import java.util.concurrent.Executor;import java.util.concurrent.Executors;/** * @Class: Downloador * @Description: 任務下載器 * @author: lling(www.cnblogs.com/liuling) * @Date: 2015/10/13 */public class Downloador { public static final String TAG = "Downloador"; private static final int THREAD_POOL_SIZE = 9; //線程池大小為9 private static final int THREAD_NUM = 3; //每個文件3個線程下載 private static final int GET_LENGTH_SUCCESS = 1; public static final Executor THREAD_POOL_EXECUTOR = Executors.newFixedThreadPool(THREAD_POOL_SIZE); private List<DownloadTask> tasks; private InnerHandler handler = new InnerHandler(); private AppContent appContent; //待下載的應用 private long downloadLength; //下載過程中記錄已下載大小 private long fileLength; private Context context; private String downloadPath; public Downloador(Context context, AppContent appContent) { this.context = context; this.appContent = appContent; this.downloadPath = DownloadUtils.getDownloadPath(); } /** * 開始下載 */ public void download() { if(TextUtils.isEmpty(downloadPath)) { Toast.makeText(context, "未找到SD卡", Toast.LENGTH_SHORT).show(); return; } if(appContent == null) { throw new IllegalArgumentException("download content can not be null"); } new Thread() { @Override public void run() { //獲取文件大小 HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(appContent.getUrl()); HttpResponse response = null; try {  response = client.execute(request);  fileLength = response.getEntity().getContentLength(); } catch (Exception e) {  Log.e(TAG, e.getMessage()); } finally {  if (request != null) {  request.abort();  } } //計算出該文件已經下載的總長度 List<DownloadInfo> lists = DownloadInfoDAO.getInstance(context.getApplicationContext())  .getDownloadInfosByUrl(appContent.getUrl()); for (DownloadInfo info : lists) {  downloadLength += info.getDownloadLength(); } //插入文件下載記錄到數據庫 DownloadFileDAO.getInstance(context.getApplicationContext()).insertDownloadFile(appContent); Message.obtain(handler, GET_LENGTH_SUCCESS).sendToTarget(); } }.start(); } /** * 開始創建AsyncTask下載 */ private void beginDownload() { Log.e(TAG, "beginDownload" + appContent.getUrl()); appContent.setStatus(AppContent.Status.WAITING); long blockLength = fileLength / THREAD_NUM; for (int i = 0; i < THREAD_NUM; i++) { long beginPosition = i * blockLength;//每條線程下載的開始位置 long endPosition = (i + 1) * blockLength;//每條線程下載的結束位置 if (i == (THREAD_NUM - 1)) { endPosition = fileLength;//如果整個文件的大小不為線程個數的整數倍，則最后一個線程的結束位置即為文件的總長度 } DownloadTask task = new DownloadTask(i, beginPosition, endPosition, this, context); task.executeOnExecutor(THREAD_POOL_EXECUTOR, appContent.getUrl()); if(tasks == null) { tasks = new ArrayList<DownloadTask>(); } tasks.add(task); } } /** * 暫停下載 */ public void pause() { for (DownloadTask task : tasks) { if (task != null && (task.getStatus() == AsyncTask.Status.RUNNING || !task.isCancelled())) { task.cancel(true); } } tasks.clear(); appContent.setStatus(AppContent.Status.PAUSED); DownloadFileDAO.getInstance(context.getApplicationContext()).updateDownloadFile(appContent); } /** * 將已下載大小歸零 */ protected synchronized void resetDownloadLength() { this.downloadLength = 0; } /** * 添加已下載大小 * 多線程訪問需加鎖 * @param size */ protected synchronized void updateDownloadLength(long size){ this.downloadLength += size; //通知更新界面 int percent = (int)((float)downloadLength * 100 / (float)fileLength); appContent.setDownloadPercent(percent); if(percent == 100 || downloadLength == fileLength) { appContent.setDownloadPercent(100); //上面計算有時候會有點誤差，算到percent=99 appContent.setStatus(AppContent.Status.FINISHED); DownloadFileDAO.getInstance(context.getApplicationContext()).updateDownloadFile(appContent); } Intent intent = new Intent(Constants.DOWNLOAD_MSG); if(appContent.getStatus() == AppContent.Status.WAITING) { appContent.setStatus(AppContent.Status.DOWNLOADING); } Bundle bundle = new Bundle(); bundle.putParcelable("appContent", appContent); intent.putExtras(bundle); context.sendBroadcast(intent); } protected String getDownloadPath() { return downloadPath; } private class InnerHandler extends Handler { @Override public void handleMessage(Message msg) { switch (msg.what) { case GET_LENGTH_SUCCESS :  beginDownload();  break; } super.handleMessage(msg); } }}

package com.bbk.lling.multitaskdownload.downloador;import android.content.Context;import android.os.AsyncTask;import android.util.Log;import com.bbk.lling.multitaskdownload.beans.DownloadInfo;import com.bbk.lling.multitaskdownload.db.DownloadInfoDAO;import org.apache.http.Header;import org.apache.http.HttpResponse;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicHeader;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.RandomAccessFile;import java.net.MalformedURLException;/** * @Class: DownloadTask * @Description: 文件下載AsyncTask * @author: lling(www.cnblogs.com/liuling) * @Date: 2015/10/13 */public class DownloadTask extends AsyncTask<String, Integer , Long> { private static final String TAG = "DownloadTask"; private int taskId; private long beginPosition; private long endPosition; private long downloadLength; private String url; private Downloador downloador; private DownloadInfoDAO downloadInfoDAO; public DownloadTask(int taskId, long beginPosition, long endPosition, Downloador downloador,  Context context) { this.taskId = taskId; this.beginPosition = beginPosition; this.endPosition = endPosition; this.downloador = downloador; downloadInfoDAO = DownloadInfoDAO.getInstance(context.getApplicationContext()); } @Override protected void onPreExecute() { Log.e(TAG, "onPreExecute"); } @Override protected void onPostExecute(Long aLong) { Log.e(TAG, url + "taskId:" + taskId + "executed");// downloador.updateDownloadInfo(null); } @Override protected void onProgressUpdate(Integer... values) { //通知downloador增加已下載大小// downloador.updateDownloadLength(values[0]); } @Override protected void onCancelled() { Log.e(TAG, "onCancelled");// downloador.updateDownloadInfo(null); } @Override protected Long doInBackground(String... params) { //這里加判斷的作用是：如果還處于等待就暫停了，運行到這里已經cancel了，就直接退出 if(isCancelled()) { return null; } url = params[0]; if(url == null) { return null; } HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(url); HttpResponse response; InputStream is; RandomAccessFile fos = null; OutputStream output = null; DownloadInfo downloadInfo = null; try { //本地文件 File file = new File(downloador.getDownloadPath() + File.separator + url.substring(url.lastIndexOf("/") + 1)); //獲取之前下載保存的信息 downloadInfo = downloadInfoDAO.getDownloadInfoByTaskIdAndUrl(taskId, url); //從之前結束的位置繼續下載 //這里加了判斷file.exists()，判斷是否被用戶刪除了，如果文件沒有下載完，但是已經被用戶刪除了，則重新下載 if(file.exists() && downloadInfo != null) { if(downloadInfo.isDownloadSuccess() == 1) {  //下載完成直接結束  return null; } beginPosition = beginPosition + downloadInfo.getDownloadLength(); downloadLength = downloadInfo.getDownloadLength(); } if(!file.exists()) { //如果此task已經下載完，但是文件被用戶刪除，則需要重新設置已下載長度，重新下載 downloador.resetDownloadLength(); } //設置下載的數據位置beginPosition字節到endPosition字節 Header header_size = new BasicHeader("Range", "bytes=" + beginPosition + "-" + endPosition); request.addHeader(header_size); //執行請求獲取下載輸入流 response = client.execute(request); is = response.getEntity().getContent(); //創建文件輸出流 fos = new RandomAccessFile(file, "rw"); //從文件的size以后的位置開始寫入 fos.seek(beginPosition); byte buffer [] = new byte[1024]; int inputSize = -1; while((inputSize = is.read(buffer)) != -1) { fos.write(buffer, 0, inputSize); downloadLength += inputSize; downloador.updateDownloadLength(inputSize); //如果暫停了，需要將下載信息存入數據庫 if (isCancelled()) {  if(downloadInfo == null) {  downloadInfo = new DownloadInfo();  }  downloadInfo.setUrl(url);  downloadInfo.setDownloadLength(downloadLength);  downloadInfo.setTaskId(taskId);  downloadInfo.setDownloadSuccess(0);  //保存下載信息到數據庫  downloadInfoDAO.insertDownloadInfo(downloadInfo);  return null; } } } catch (MalformedURLException e) { Log.e(TAG, e.getMessage()); } catch (IOException e) { Log.e(TAG, e.getMessage()); } finally{ try{ if (request != null) {  request.abort(); } if(output != null) {  output.close(); } if(fos != null) {  fos.close(); } } catch(Exception e) { e.printStackTrace(); } } //執行到這里，說明該task已經下載完了 if(downloadInfo == null) { downloadInfo = new DownloadInfo(); } downloadInfo.setUrl(url); downloadInfo.setDownloadLength(downloadLength); downloadInfo.setTaskId(taskId); downloadInfo.setDownloadSuccess(1); //保存下載信息到數據庫 downloadInfoDAO.insertDownloadInfo(downloadInfo); return null; }}

package com.bbk.lling.multitaskdownload.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * @Class: DBHelper * @Description: 數據庫幫助類 * @author: lling(www.cnblogs.com/liuling) * @Date: 2015/10/14 */public class DBHelper extends SQLiteOpenHelper { public DBHelper(Context context) { super(context, "download.db", null, 1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("create table download_info(_id INTEGER PRIMARY KEY AUTOINCREMENT, task_id INTEGER, " + "download_length INTEGER, url VARCHAR(255), is_success INTEGER)"); db.execSQL("create table download_file(_id INTEGER PRIMARY KEY AUTOINCREMENT, app_name VARCHAR(255), " + "url VARCHAR(255), download_percent INTEGER, status INTEGER)"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { }}

package com.bbk.lling.multitaskdownload.db;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.text.TextUtils;import android.util.Log;import com.bbk.lling.multitaskdownload.beans.AppContent;import java.util.ArrayList;import java.util.List;/** * @Class: DownloadFileDAO * @Description: 每個文件下載狀態記錄的數據庫操作類 * @author: lling(www.cnblogs.com/liuling) * @Date: 2015/10/13 */public class DownloadFileDAO { private static final String TAG = "DownloadFileDAO"; private static DownloadFileDAO dao=null; private Context context; private DownloadFileDAO(Context context) { this.context=context; } synchronized public static DownloadFileDAO getInstance(Context context){ if(dao==null){ dao=new DownloadFileDAO(context); } return dao; } /** * 獲取數據庫連接 * @return */ public SQLiteDatabase getConnection() { SQLiteDatabase sqliteDatabase = null; try { sqliteDatabase= new DBHelper(context).getReadableDatabase(); } catch (Exception e) { Log.e(TAG, e.getMessage()); } return sqliteDatabase; } /** * 插入數據 * @param appContent */ public void insertDownloadFile(AppContent appContent) { if(appContent == null) { return; } //如果本地已經存在，直接修改 if(getAppContentByUrl(appContent.getUrl()) != null) { updateDownloadFile(appContent); return; } SQLiteDatabase database = getConnection(); try { String sql = "insert into download_file(app_name, url, download_percent, status) values (?,?,?,?)"; Object[] bindArgs = { appContent.getName(), appContent.getUrl(), appContent.getDownloadPercent()  , appContent.getStatus().getValue()}; database.execSQL(sql, bindArgs); } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } } } /** * 根據url獲取下載文件信息 * @param url * @return */ public AppContent getAppContentByUrl(String url) { if(TextUtils.isEmpty(url)) { return null; } SQLiteDatabase database = getConnection(); AppContent appContent = null; Cursor cursor = null; try { String sql = "select * from download_file where url=?"; cursor = database.rawQuery(sql, new String[] { url }); if (cursor.moveToNext()) { appContent = new AppContent(cursor.getString(1), cursor.getString(2)); appContent.setDownloadPercent(cursor.getInt(3)); appContent.setStatus(AppContent.Status.getByValue(cursor.getInt(4))); } } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } if (null != cursor) { cursor.close(); } } return appContent; } /** * 更新下載信息 * @param appContent */ public void updateDownloadFile(AppContent appContent) { if(appContent == null) { return; } SQLiteDatabase database = getConnection(); try { Log.e(TAG, "update download_file,app name:" + appContent.getName() + ",url:" + appContent.getUrl()  + ",percent" + appContent.getDownloadPercent() + ",status:" + appContent.getStatus().getValue()); String sql = "update download_file set app_name=?, url=?, download_percent=?, status=? where url=?"; Object[] bindArgs = {appContent.getName(), appContent.getUrl(), appContent.getDownloadPercent()  , appContent.getStatus().getValue(), appContent.getUrl()}; database.execSQL(sql, bindArgs); } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } } } /** * 獲取所有下載文件記錄 * @return */ public List<AppContent> getAll() { SQLiteDatabase database = getConnection(); List<AppContent> list = new ArrayList<AppContent>(); Cursor cursor = null; try { String sql = "select * from download_file"; cursor = database.rawQuery(sql, null); while (cursor.moveToNext()) { AppContent appContent = new AppContent(cursor.getString(1), cursor.getString(2)); appContent.setDownloadPercent(cursor.getInt(3)); appContent.setStatus(AppContent.Status.getByValue(cursor.getInt(4))); list.add(appContent); } } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } if (null != cursor) { cursor.close(); } } return list; } /** * 根據url刪除記錄 * @param url */ public void delByUrl(String url) { if(TextUtils.isEmpty(url)) { return; } SQLiteDatabase database = getConnection(); try { String sql = "delete from download_file where url=?"; Object[] bindArgs = { url }; database.execSQL(sql, bindArgs); } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } } }}

package com.bbk.lling.multitaskdownload.db;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.text.TextUtils;import android.util.Log;import com.bbk.lling.multitaskdownload.beans.DownloadInfo;import java.util.ArrayList;import java.util.List;/** * @Class: DownloadInfoDAO * @Description: 每個單獨線程下載信息記錄的數據庫操作類 * @author: lling(www.cnblogs.com/liuling) * @Date: 2015/10/13 */public class DownloadInfoDAO { private static final String TAG = "DownloadInfoDAO"; private static DownloadInfoDAO dao=null; private Context context; private DownloadInfoDAO(Context context) { this.context=context; } synchronized public static DownloadInfoDAO getInstance(Context context){ if(dao==null){ dao=new DownloadInfoDAO(context); } return dao; } /** * 獲取數據庫連接 * @return */ public SQLiteDatabase getConnection() { SQLiteDatabase sqliteDatabase = null; try { sqliteDatabase= new DBHelper(context).getReadableDatabase(); } catch (Exception e) { Log.e(TAG, e.getMessage()); } return sqliteDatabase; } /** * 插入數據 * @param downloadInfo */ public void insertDownloadInfo(DownloadInfo downloadInfo) { if(downloadInfo == null) { return; } //如果本地已經存在，直接修改 if(getDownloadInfoByTaskIdAndUrl(downloadInfo.getTaskId(), downloadInfo.getUrl()) != null) { updateDownloadInfo(downloadInfo); return; } SQLiteDatabase database = getConnection(); try { String sql = "insert into download_info(task_id, download_length, url, is_success) values (?,?,?,?)"; Object[] bindArgs = { downloadInfo.getTaskId(), downloadInfo.getDownloadLength(),  downloadInfo.getUrl(), downloadInfo.isDownloadSuccess()}; database.execSQL(sql, bindArgs); } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } } } public List<DownloadInfo> getDownloadInfosByUrl(String url) { if(TextUtils.isEmpty(url)) { return null; } SQLiteDatabase database = getConnection(); List<DownloadInfo> list = new ArrayList<DownloadInfo>(); Cursor cursor = null; try { String sql = "select * from download_info where url=?"; cursor = database.rawQuery(sql, new String[] { url }); while (cursor.moveToNext()) { DownloadInfo info = new DownloadInfo(); info.setTaskId(cursor.getInt(1)); info.setDownloadLength(cursor.getLong(2)); info.setDownloadSuccess(cursor.getInt(4)); info.setUrl(cursor.getString(3)); list.add(info); } } catch (Exception e) { e.printStackTrace(); } finally { if (null != database) { database.close(); } if (null != cursor) { cursor.close(); } } return list; } /** * 根據taskid和url獲取下載信息 * @param taskId * @param url * @return */ public DownloadInfo getDownloadInfoByTaskIdAndUrl(int taskId, String url) { if(TextUtils.isEmpty(url)) { return null; } SQLiteDatabase database = getConnection(); DownloadInfo info = null; Cursor cursor = null; try { String sql = "select * from download_info where url=? and task_id=?"; cursor = database.rawQuery(sql, new String[] { url, String.valueOf(taskId) }); if (cursor.moveToNext()) { info = new DownloadInfo(); info.setTaskId(cursor.getInt(1)); info.setDownloadLength(cursor.getLong(2)); info.setDownloadSuccess(cursor.getInt(4)); info.setUrl(cursor.getString(3)); } } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } if (null != cursor) { cursor.close(); } } return info; } /** * 更新下載信息 * @param downloadInfo */ public void updateDownloadInfo(DownloadInfo downloadInfo) { if(downloadInfo == null) { return; } SQLiteDatabase database = getConnection(); try { String sql = "update download_info set download_length=?, is_success=? where task_id=? and url=?"; Object[] bindArgs = { downloadInfo.getDownloadLength(), downloadInfo.isDownloadSuccess(),  downloadInfo.getTaskId(), downloadInfo.getUrl() }; database.execSQL(sql, bindArgs); } catch (Exception e) { Log.e(TAG, e.getMessage()); } finally { if (null != database) { database.close(); } } }}