多线程下载
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<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.INTERNET"/>
public class Main2Activity extends FragmentActivity { private static final String TAG = MainActivity.class.getSimpleName(); private ProgressBar mProgressBar; private Button start; private Button pause; private TextView total; private int max; private DownloadUtil mDownloadUtil; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main2); total= (TextView) findViewById(R.id.textView); start= (Button) findViewById(R.id.start); pause= (Button) findViewById(R.id.delete); mProgressBar= (ProgressBar) findViewById(R.id.progressBar); String urlString = "http://2449.vod.myqcloud.com/2449_bfbbfa3cea8f11e5aac3db03cda99974.f20.mp4"; String localPath = Environment.getExternalStorageDirectory() .getAbsolutePath() + "/local"; mDownloadUtil = new DownloadUtil(2, localPath, "f20.mp4", urlString, this); mDownloadUtil.setOnDownloadListener(new DownloadUtil.OnDownloadListener() { @Override public void downloadStart(int fileSize) { // TODO Auto-generated method stub Log.w(TAG, "fileSize::" + fileSize); max = fileSize; mProgressBar.setMax(fileSize); } @Override public void downloadProgress(int downloadedSize) { // TODO Auto-generated method stub Log.w(TAG, "Compelete::" + downloadedSize); mProgressBar.setProgress(downloadedSize); total.setText((int) downloadedSize * 100 / max + "%"); } @Override public void downloadEnd() { // TODO Auto-generated method stub Log.w(TAG, "ENd"); } }); start.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub mDownloadUtil.start(); } }); pause.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub mDownloadUtil.pause(); } }); }}
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.lenovo.zhonghelianxi.view.Main2Activity"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" android:layout_alignParentTop="true" android:layout_marginLeft="23dp" android:layout_marginStart="23dp" android:layout_marginTop="18dp" android:text="TextView" /> <ProgressBar android:id="@+id/progressBar" style="?android:attr/progressBarStyleHorizontal" android:layout_width="fill_parent" android:layout_height="7.5dp" android:max="100" android:progress="100" android:layout_marginRight="8dp" android:layout_below="@+id/textView" android:visibility="visible"/> <Button android:id="@+id/start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_toEndOf="@+id/textView" android:layout_toRightOf="@+id/textView" android:text="下载" /> <Button android:id="@+id/delete" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_marginLeft="48dp" android:layout_marginStart="48dp" android:layout_toEndOf="@+id/start" android:layout_toRightOf="@+id/start" android:text="暂停" /></RelativeLayout>
public class DownlaodSqlTool { private DownLoadHelper dbHelper; public DownlaodSqlTool(Context context){ dbHelper=new DownLoadHelper(context); } /** * 创建下载的具体信息 */ public void insertInfos(List<DownloadInfo> infos) { SQLiteDatabase database = dbHelper.getWritableDatabase(); for (DownloadInfo info : infos) { String sql = "insert into download_info(thread_id,start_pos, end_pos,compelete_size,url) values (?,?,?,?,?)"; Object[] bindArgs = { info.getThreadId(), info.getStartPos(), info.getEndPos(), info.getCompeleteSize(), info.getUrl() }; database.execSQL(sql, bindArgs); } } /** * 得到下载具体信息 */ public List<DownloadInfo> getInfos(String urlstr) { List<DownloadInfo> list = new ArrayList<DownloadInfo>(); SQLiteDatabase database = dbHelper.getWritableDatabase(); String sql = "select thread_id, start_pos, end_pos,compelete_size,url from download_info where url=?"; Cursor cursor = database.rawQuery(sql, new String[] { urlstr }); while (cursor.moveToNext()) { DownloadInfo info = new DownloadInfo(cursor.getInt(0), cursor.getInt(1), cursor.getInt(2), cursor.getInt(3), cursor.getString(4)); list.add(info); } return list; } /** * 更新数据库中的下载信息 */ public void updataInfos(int threadId, int compeleteSize, String urlstr) { SQLiteDatabase database = dbHelper.getWritableDatabase(); String sql = "update download_info set compelete_size=? where thread_id=? and url=?"; Object[] bindArgs = { compeleteSize, threadId, urlstr }; database.execSQL(sql, bindArgs); } /** * 关闭数据库 */ public void closeDb() { dbHelper.close(); } /** * 下载完成后删除数据库中的数据 */ public void delete(String url) { SQLiteDatabase database = dbHelper.getWritableDatabase(); database.delete("download_info", "url=?", new String[] { url }); }}
public class DownLoadHelper extends SQLiteOpenHelper{ private static final String SQL_NAME = "download.db"; private static final int DOWNLOAD_VERSION=1; public DownLoadHelper(Context context) { super(context, SQL_NAME, null, DOWNLOAD_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("create table download_info(_id integer PRIMARY KEY AUTOINCREMENT, thread_id integer, " + "start_pos integer, end_pos integer, compelete_size integer,url char)"); } @Override public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) { }}
public class DownloadHttpTool { /** * * 利用Http协议进行多线程下载具体实践类 */ private static final String TAG = DownloadHttpTool.class.getSimpleName(); private int threadCount;//线程数量 private String urlstr;//URL地址 private Context mContext; private Handler mHandler; private List<DownloadInfo> downloadInfos;//保存下载信息的类 private String localPath;//目录 private String fileName;//文件名 private int fileSize; private DownlaodSqlTool sqlTool;//文件信息保存的数据库操作类 private enum Download_State { Downloading, Pause, Ready;//利用枚举表示下载的三种状态 } private Download_State state = Download_State.Ready;//当前下载状态 private int globalCompelete = 0;//所有线程下载的总数 public DownloadHttpTool(int threadCount, String urlString, String localPath, String fileName, Context context, Handler handler) { super(); this.threadCount = threadCount; this.urlstr = urlString; this.localPath = localPath; this.mContext = context; this.mHandler = handler; this.fileName = fileName; sqlTool = new DownlaodSqlTool(mContext); } //在开始下载之前需要调用ready方法进行配置 public void ready() { Log.w(TAG, "ready"); globalCompelete = 0; downloadInfos = sqlTool.getInfos(urlstr); if (downloadInfos.size() == 0) { initFirst(); } else { File file = new File(localPath + "/" + fileName); if (!file.exists()) { sqlTool.delete(urlstr); initFirst(); } else { fileSize = downloadInfos.get(downloadInfos.size() - 1) .getEndPos(); for (DownloadInfo info : downloadInfos) { globalCompelete += info.getCompeleteSize(); } Log.w(TAG, "globalCompelete:::" + globalCompelete); } } } public void start() { Log.w(TAG, "start"); if (downloadInfos != null) { if (state == Download_State.Downloading) { return; } state = Download_State.Downloading; for (DownloadInfo info : downloadInfos) { Log.v(TAG, "startThread"); new DownloadThread(info.getThreadId(), info.getStartPos(), info.getEndPos(), info.getCompeleteSize(), info.getUrl()).start(); } } } public void pause() { state = Download_State.Pause; sqlTool.closeDb(); } public void delete(){ compelete(); File file = new File(localPath + "/" + fileName); file.delete(); } public void compelete() { sqlTool.delete(urlstr); sqlTool.closeDb(); } public int getFileSize() { return fileSize; } public int getCompeleteSize() { return globalCompelete; } //第一次下载初始化 private void initFirst() { Log.w(TAG, "initFirst"); try { URL url = new URL(urlstr); HttpURLConnection connection = (HttpURLConnection) url .openConnection(); connection.setConnectTimeout(5000); connection.setRequestMethod("GET"); fileSize = connection.getContentLength(); Log.w(TAG, "fileSize::" + fileSize); File fileParent = new File(localPath); if (!fileParent.exists()) { fileParent.mkdir(); } File file = new File(fileParent, fileName); if (!file.exists()) { file.createNewFile(); } // 本地访问文件 RandomAccessFile accessFile = new RandomAccessFile(file, "rwd"); accessFile.setLength(fileSize); accessFile.close(); connection.disconnect(); } catch (Exception e) { e.printStackTrace(); } int range = fileSize / threadCount; downloadInfos = new ArrayList<DownloadInfo>(); for (int i = 0; i < threadCount - 1; i++) { DownloadInfo info = new DownloadInfo(i, i * range, (i + 1) * range - 1, 0, urlstr); downloadInfos.add(info); } DownloadInfo info = new DownloadInfo(threadCount - 1, (threadCount - 1) * range, fileSize - 1, 0, urlstr); downloadInfos.add(info); sqlTool.insertInfos(downloadInfos); } //自定义下载线程 private class DownloadThread extends Thread { private int threadId; private int startPos; private int endPos; private int compeleteSize; private String urlstr; private int totalThreadSize; public DownloadThread(int threadId, int startPos, int endPos, int compeleteSize, String urlstr) { this.threadId = threadId; this.startPos = startPos; this.endPos = endPos; totalThreadSize = endPos - startPos + 1; this.urlstr = urlstr; this.compeleteSize = compeleteSize; } @Override public void run() { HttpURLConnection connection = null; RandomAccessFile randomAccessFile = null; InputStream is = null; try { randomAccessFile = new RandomAccessFile(localPath + "/" + fileName, "rwd"); randomAccessFile.seek(startPos + compeleteSize); URL url = new URL(urlstr); connection = (HttpURLConnection) url.openConnection(); connection.setConnectTimeout(5000); connection.setRequestMethod("GET"); connection.setRequestProperty("Range", "bytes=" + (startPos + compeleteSize) + "-" + endPos); is = connection.getInputStream(); byte[] buffer = new byte[1024]; int length = -1; while ((length = is.read(buffer)) != -1) { randomAccessFile.write(buffer, 0, length); compeleteSize += length; Message message = Message.obtain(); message.what = threadId; message.obj = urlstr; message.arg1 = length; mHandler.sendMessage(message); sqlTool.updataInfos(threadId, compeleteSize, urlstr); Log.w(TAG, "Threadid::" + threadId + " compelete::" + compeleteSize + " total::" + totalThreadSize); if (compeleteSize >= totalThreadSize) { break; } if (state != Download_State.Downloading) { break; } } } catch (Exception e) { e.printStackTrace(); } finally { try { if (is != null) { is.close(); } randomAccessFile.close(); connection.disconnect(); } catch (Exception e) { e.printStackTrace(); } } } }}
public class DownloadInfo { /** * 保存每个下载线程下载信息类 * */ private int threadId;// 下载器id private int startPos;// 开始点 private int endPos;// 结束点 private int compeleteSize;// 完成度 private String url;// 下载文件的URL地址 public DownloadInfo(int threadId, int startPos, int endPos, int compeleteSize, String url) { this.threadId = threadId; this.startPos = startPos; this.endPos = endPos; this.compeleteSize = compeleteSize; this.url = url; } public DownloadInfo() { } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public int getThreadId() { return threadId; } public void setThreadId(int threadId) { this.threadId = threadId; } public int getStartPos() { return startPos; } public void setStartPos(int startPos) { this.startPos = startPos; } public int getEndPos() { return endPos; } public void setEndPos(int endPos) { this.endPos = endPos; } public int getCompeleteSize() { return compeleteSize; } public void setCompeleteSize(int compeleteSize) { this.compeleteSize = compeleteSize; } @Override public String toString() { return "DownloadInfo [threadId=" + threadId + ", startPos=" + startPos + ", endPos=" + endPos + ", compeleteSize=" + compeleteSize + "]"; }}
/** * 将下载方法封装在此类 * 提供下载，暂停，删除，以及重置的方法 */public class DownloadUtil { private DownloadHttpTool mDownloadHttpTool; private OnDownloadListener onDownloadListener; private int fileSize; private int downloadedSize = 0; @SuppressLint("HandlerLeak") private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub super.handleMessage(msg); int length = msg.arg1; synchronized (this) {//加锁保证已下载的正确性 downloadedSize += length; } if (onDownloadListener != null) { onDownloadListener.downloadProgress(downloadedSize); } if (downloadedSize >= fileSize) { mDownloadHttpTool.compelete(); if (onDownloadListener != null) { onDownloadListener.downloadEnd(); } } } }; public DownloadUtil(int threadCount, String filePath, String filename, String urlString, Context context) { mDownloadHttpTool = new DownloadHttpTool(threadCount, urlString, filePath, filename, context, mHandler); } //下载之前首先异步线程调用ready方法获得文件大小信息，之后调用开始方法 public void start() { new AsyncTask<Void,Void,Void>() { @Override protected Void doInBackground(Void... arg0) { // TODO Auto-generated method stub mDownloadHttpTool.ready(); return null; } @Override protected void onPostExecute(Void result) { // TODO Auto-generated method stub super.onPostExecute(result); fileSize = mDownloadHttpTool.getFileSize(); downloadedSize = mDownloadHttpTool.getCompeleteSize(); Log.w("Tag", "downloadedSize::" + downloadedSize); if (onDownloadListener != null) { onDownloadListener.downloadStart(fileSize); } mDownloadHttpTool.start(); } }.execute(); } public void pause() { mDownloadHttpTool.pause(); } public void delete(){ mDownloadHttpTool.delete(); } public void reset(){ mDownloadHttpTool.delete(); start(); } public void setOnDownloadListener(OnDownloadListener onDownloadListener) { this.onDownloadListener = onDownloadListener; } //下载回调接口 public interface OnDownloadListener { public void downloadStart(int fileSize); public void downloadProgress(int downloadedSize);//记录当前所有线程下总和 public void downloadEnd(); }}
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