本文主要是介绍Greendao+多线程断点续传，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
客官不要着急，下面给出你的困扰。想要用greendao首先需要配置
1、在app的Gradle中配置：
}
2、在project的Gradle中配置：
3.在app的Gradle（android）配置数据库版本等信息
greendao {
schemaVersion 1
daoPackage 'com.bwie.test.greendaodemo.gen'
targetGenDir 'src/main/java'
}
daoPackage 由GreenDao自动生成代码所在的包名，默认的是在项目包下面新建一个gen。
targetGenDir 设置自动生成代码的目录
权限也粘一下的啦
<uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
因为grenndao的独特性，自动生成三个类，下面只给出实体类以及需要的操作
一点也不吝啬，别着急，实体类在这呢，记得生成实体类之后在buils下make project一下，让他自动生成三大类
@Entitypublic class User {@Idprivate Long id;private Integer thread_id;private Integer start_pos;private Integer end_pos;private Integer compelete_size;private String url;@Generated(hash = 2041931179)public User(Long id, Integer thread_id, Integer start_pos, Integer end_pos,Integer compelete_size, String url) {this.id = id;this.thread_id = thread_id;this.start_pos = start_pos;this.end_pos = end_pos;this.compelete_size = compelete_size;this.url = url;}@Generated(hash = 586692638)public User() {}public Long getId() {return this.id;}public void setId(Long id) {this.id = id;}public Integer getThread_id() {return this.thread_id;}public void setThread_id(Integer thread_id) {this.thread_id = thread_id;}public Integer getStart_pos() {return this.start_pos;}public void setStart_pos(Integer start_pos) {this.start_pos = start_pos;}public Integer getEnd_pos() {return this.end_pos;}public void setEnd_pos(Integer end_pos) {this.end_pos = end_pos;}public Integer getCompelete_size() {return this.compelete_size;}public void setCompelete_size(Integer compelete_size) {this.compelete_size = compelete_size;}public String getUrl() {return this.url;}public void setUrl(String url) {this.url = url;}}
好人做到低，下面附上需要的单例模式，因为本人用的是单例模式，用来数据库的初始化，并且获得操作类
public class App extends Application {public static UserDao userDao;@Overridepublic void onCreate() {super.onCreate();DaoMaster.DevOpenHelper devOpenHelper = new DaoMaster.DevOpenHelper(this, "lenvess.db", null);DaoMaster daoMaster = new DaoMaster(devOpenHelper.getWritableDb());DaoSession daoSession = daoMaster.newSession();userDao = daoSession.getUserDao();}
}
第一个类，主要是记录的类，修改，添加和最后下载完清空数据库的类
public class DownlaodSqlTool {/*** 创建下载的具体信息*/public void insertInfos(List<DownloadInfo> infos) {for (DownloadInfo info : infos) {User user = new User(null, info.getThreadId(), info.getStartPos(), info.getEndPos(), info.getCompeleteSize(), info.getUrl());userDao.insert(user);}}/*** 得到下载具体信息*/public List<DownloadInfo> getInfos(String urlstr) {List<DownloadInfo> list = new ArrayList<DownloadInfo>();List<User> list1 = userDao.queryBuilder().where(UserDao.Properties.Url.eq(urlstr)).build().list();for (User user : list1) {DownloadInfo infoss = new DownloadInfo(user.getThread_id(), user.getStart_pos(), user.getEnd_pos(),user.getCompelete_size(), user.getUrl());Log.d("main-----", infoss.toString());list.add(infoss);}return list;}/*** 更新数据库中的下载信息*/public void updataInfos(int threadId, int compeleteSize, String urlstr) {User user = userDao.queryBuilder().where(UserDao.Properties.Thread_id.eq(threadId), UserDao.Properties.Url.eq(urlstr)).build().unique();user.setCompelete_size(compeleteSize);userDao.update(user);}/*** 下载完成后删除数据库中的数据*/public void delete(String url) {userDao.deleteAll();}}
2.多线程下载的实践类
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();}//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;}public void delete() {compelete();File file = new File(localPath + "/" + fileName);file.delete();}public void compelete() {sqlTool.delete(urlstr);}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;}@Overridepublic 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();}}}}
}
3.保存每个下载线程下载信息的类
public class DownloadInfo { /** * 保存每个下载线程下载信息类**/private int threadId;// 下载器idprivate 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;}@Overridepublic String toString() {return "DownloadInfo [threadId=" + threadId + ", startPos=" + startPos+ ", endPos=" + endPos + ", compeleteSize=" + compeleteSize+ "]";}}
4.这是一个接口类
public class DownloadUtil {private DownloadHttpTool mDownloadHttpTool;private OnDownloadListener onDownloadListener;private int fileSize;private int downloadedSize = 0;@SuppressLint("HandlerLeak")private Handler mHandler = new Handler() {@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubsuper.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>() {@Overrideprotected Void doInBackground(Void... arg0) {// TODO Auto-generated method stubmDownloadHttpTool.ready();return null;}@Overrideprotected void onPostExecute(Void result) {// TODO Auto-generated method stubsuper.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();}}
5.主的activity的类
public class MainActivity extends AppCompatActivity {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;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);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_22ca37a6ea9011e5acaaf51d105342e3.f20.mp4";String localPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/local";mDownloadUtil = new DownloadUtil(2, localPath, "adc.mp4", urlString,this);mDownloadUtil.setOnDownloadListener(new DownloadUtil.OnDownloadListener() {@Overridepublic void downloadStart(int fileSize) {// TODO Auto-generated method stubLog.w(TAG, "fileSize::" + fileSize);max = fileSize;mProgressBar.setMax(fileSize);}@Overridepublic void downloadProgress(int downloadedSize) {// TODO Auto-generated method stubLog.w(TAG, "Compelete::" + downloadedSize);mProgressBar.setProgress(downloadedSize);total.setText((int) downloadedSize * 100 / max + "%");}@Overridepublic void downloadEnd() {// TODO Auto-generated method stubLog.w(TAG, "ENd");}});start.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubmDownloadUtil.start();}});pause.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubmDownloadUtil.pause();}});}
好了，布局也给你们了
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"><TextViewandroid: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" /><ProgressBarandroid:id="@+id/progressBar"style="?android:attr/progressBarStyleHorizontal"android:layout_width="fill_parent"android:layout_height="7.5dp"android:layout_below="@+id/textView"android:layout_marginRight="8dp"android:max="100"android:progress="100"android:visibility="visible" /><Buttonandroid: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" /><Buttonandroid: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>
最后，客官们注意了，这里面的下载路径是local，自己更改喽。粘的难免出错，下面是Githb地址
GitHub
效果图，布局可以更改
这篇关于Greendao+多线程断点续传的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
