斷點多線程下載的幾個關(guān)鍵點：①：得到要下載的文件大小后，均分給幾個線程。②：使用RandomAccessFile類進(jìn)行讀寫，可以指定開始寫入的位置。③：數(shù)據(jù)庫保存下載信息，下一次繼續(xù)下載的時候從數(shù)據(jù)庫取出數(shù)據(jù)，然后從上次下載結(jié)束的地方開始。
這里我使用了FinalDb的數(shù)據(jù)庫框架，同時在內(nèi)存中存儲了一份所有線程的下載信息，負(fù)責(zé)時時更新和查詢下載進(jìn)度。我測試用的是百度云網(wǎng)盤，文件大小50M左右。注意，線程中指定了開始結(jié)束下載位置的網(wǎng)絡(luò)請求成功的返回碼是206，并不是200。
效果圖：
線程類：線程類負(fù)責(zé)具體的下載，線程的下載信息被存儲到了數(shù)據(jù)庫。線程開始下載時，根據(jù)線程ID查詢自己的存儲信息，然后開始從指定的位置下載和寫入文件。完畢后根據(jù)自己的當(dāng)前下載結(jié)果設(shè)置自己當(dāng)前的下載狀態(tài)。時時的下載進(jìn)度存儲只存儲到了內(nèi)存，只在本次下載結(jié)束才存儲到數(shù)據(jù)庫。
public class DownloadThread extends Thread { /** * 數(shù)據(jù)庫操作工具 */ private FinalDb finalDb; /** * 下載狀態(tài)：未開始 */ public static final int STATE_READY = 1; /** * 下載狀態(tài)：下載中 */ public static final int STATE_LOADING = 2; /** * 下載狀態(tài)：下載暫停中 */ public static final int STATE_PAUSING = 3; /** * 下載狀態(tài)：下載完成 */ public static final int STATE_FINISH = 4; /** * 下載狀態(tài) */ public int downloadState; /** * 線程ID */ private int threadID; /** * 要下載的URL路徑 */ private String url; /** * 本線程要下載的文件 */ public RandomAccessFile file; /** * 構(gòu)造器 */ public DownloadThread(Context context, int threadID, String downloadUrl, RandomAccessFile randomAccessFile) { this.threadID = threadID; this.url = downloadUrl; this.file = randomAccessFile; finalDb = DBUtil.getFinalDb(context); } @Override public void run() { //數(shù)據(jù)庫查詢本線程下載進(jìn)度 List<ThreadDownloadInfoBean> list = finalDb.findAllByWhere(ThreadDownloadInfoBean.class, "threadID='" + threadID + "'"); //下載信息存放到內(nèi)存 if (list.get(0) != null) { MapUtil.map.put(threadID, list.get(0)); } //取出實體類 ThreadDownloadInfoBean bean = MapUtil.map.get(threadID); Utils.Print("bean：" + bean.toString()); InputStream is; HttpURLConnection conn; try { Utils.Print("線程" + threadID + "開始連接"); conn = (HttpURLConnection) new URL(url).openConnection(); conn.setConnectTimeout(5000); conn.setReadTimeout(5000); conn.setRequestMethod("GET"); //設(shè)置下載開始和結(jié)束的位置 conn.setRequestProperty("Range", "bytes=" + (bean.startDownloadPosition + bean.downloadedSize) + "-" + bean.endDownloadPosition); conn.connect(); if (conn.getResponseCode() == 206) { //更改下載狀態(tài) downloadState = STATE_LOADING; bean.downloadState = STATE_LOADING; Utils.Print("線程" + threadID + "連接成功"); is = conn.getInputStream(); // 1K的數(shù)據(jù)緩沖 byte[] bs = new byte[1024]; // 讀取到的數(shù)據(jù)長度 int len; //從指定的位置開始下載 file.seek(bean.startDownloadPosition); // 循環(huán)讀取，當(dāng)已經(jīng)下載的大小達(dá)到了指定的本線程負(fù)責(zé)的大小時跳出循環(huán)，線程之間負(fù)責(zé)的文件首尾有重合的話沒有影響，因為寫入的內(nèi)容時相同的 while ((len = is.read(bs)) != -1) { //不用在這個循環(huán)里面更新數(shù)據(jù)庫 file.write(bs, 0, len); //時時更新內(nèi)存中的已下載大小信息 bean.downloadedSize += len; //如果調(diào)用者暫停下載，則跳出結(jié)束方法 if (downloadState == STATE_PAUSING) { Utils.Print("線程" + threadID + "暫停下載"); break; } } is.close(); file.close(); } else { Utils.Print("線程" + threadID + "連接失敗"); } conn.disconnect(); //如果這個線程已經(jīng)下載完了自己負(fù)責(zé)的部分就修改下載狀態(tài) if (bean.downloadedSize >= bean.downloadTotalSize) { bean.downloadState = STATE_FINISH; } else { bean.downloadState = STATE_PAUSING; } //內(nèi)存中信息更新至數(shù)據(jù)庫 finalDb.update(bean, "threadID='" + bean.threadID + "'"); } catch (IOException e) { Utils.Print("線程" + threadID + "IO異常"); e.printStackTrace(); } }}線程信息的封裝類：負(fù)責(zé)存儲每個線程的ID，開始下載的位置，結(jié)束下載的位置，已經(jīng)下載的大小，下載狀態(tài)等；這個類用FinalDb數(shù)據(jù)庫存儲到數(shù)據(jù)庫，一定要寫get,set方法和空參構(gòu)造器
@Table(name = "ThreadInfo")public class ThreadDownloadInfoBean { /** * id */ public int id; /** * 線程ID */ public int threadID; /** * 本線程時時下載開始的位置 */ public long startDownloadPosition; /** * 本線程時時下載結(jié)束的位置 */ public long endDownloadPosition; /** * 本線程負(fù)責(zé)下載的文件大小 */ public long downloadTotalSize; /** * 已經(jīng)下載了的文件大小 */ public long downloadedSize; /** * 本線程的下載狀態(tài) */ public int downloadState; public ThreadDownloadInfoBean() { } public ThreadDownloadInfoBean(int downloadState, long downloadedSize, long downloadTotalSize, long endDownloadPosition, long startDownloadPosition, int threadID) { this.downloadState = downloadState; this.downloadedSize = downloadedSize; this.downloadTotalSize = downloadTotalSize; this.endDownloadPosition = endDownloadPosition; this.startDownloadPosition = startDownloadPosition; this.threadID = threadID; } public int getId() { return id; } public void setId(int id) { this.id = id; } public int getThreadID() { return threadID; } public void setThreadID(int threadID) { this.threadID = threadID; } public long getStartDownloadPosition() { return startDownloadPosition; } public void setStartDownloadPosition(long startDownloadPosition) { this.startDownloadPosition = startDownloadPosition; } public long getEndDownloadPosition() { return endDownloadPosition; } public void setEndDownloadPosition(long endDownloadPosition) { this.endDownloadPosition = endDownloadPosition; } public long getDownloadTotalSize() { return downloadTotalSize; } public void setDownloadTotalSize(long downloadTotalSize) { this.downloadTotalSize = downloadTotalSize; } public long getDownloadedSize() { return downloadedSize; } public void setDownloadedSize(long downloadedSize) { this.downloadedSize = downloadedSize; } public int getDownloadState() { return downloadState; } public void setDownloadState(int downloadState) { this.downloadState = downloadState; } @Override public String toString() { return "ThreadDownloadInfoBean{" + "id=" + id + ", threadID=" + threadID + ", startDownloadPosition=" + startDownloadPosition + ", endDownloadPosition=" + endDownloadPosition + ", downloadTotalSize=" + downloadTotalSize + ", downloadedSize=" + downloadedSize + ", downloadState=" + downloadState + '}'; }}下載工具類：這個類負(fù)責(zé)得到下載文件大小，分配線程下載大小，管理下載線程
public class DownUtil { /** * 數(shù)據(jù)庫操作工具 */ public FinalDb finalDb; /** * 下載狀態(tài)：準(zhǔn)備好 */ public static final int STATE_READY = 1; /** * 下載狀態(tài)：下載中 */ public static final int STATE_LOADING = 2; /** * 下載狀態(tài)：暫停中 */ public static final int STATE_PAUSING = 3; /** * 下載狀態(tài)：下載完成 */ public static final int STATE_FINISH = 4; /** * 下載狀態(tài) */ public int downloadState; /** * context */ private Context context; /** * 要下載文件的大小 */ public long fileSize; /** * 線程集合 */ private ArrayList<DownloadThread> threadList = new ArrayList<>(); /** * 構(gòu)造器 */ public DownUtil(Context context) { this.context = context; finalDb = DBUtil.getFinalDb(context); judgeDownState(); } /** * 初始化時判斷下載狀態(tài) */ public void judgeDownState() { //取出數(shù)據(jù)庫中的下載信息，存儲到內(nèi)存中 List<ThreadDownloadInfoBean> list = finalDb.findAll(ThreadDownloadInfoBean.class); if (list != null && list.size() == DownloadActivity.threadNum) { for (int i = 0; i < list.size(); i++) { MapUtil.map.put(i, list.get(i)); } } //查詢SP中是否存儲過要下載的文件大小 Long spFileSize = SPUtil.getInstance(context).getLong(DownloadActivity.fileName, 0L); long downloadedSize = getFinishedSize(); //SP中或者數(shù)據(jù)庫中沒有查詢到說明從沒有進(jìn)行過下載 if (spFileSize == 0 || downloadedSize == 0) { downloadState = STATE_READY; } else if (downloadedSize >= spFileSize) { downloadState = STATE_FINISH; } else { downloadState = STATE_PAUSING; fileSize = spFileSize; } } /** * 點擊了開始按鈕 */ public void clickDownloadBtn() { if (downloadState == STATE_READY) { startDownload(); } else if (downloadState == STATE_PAUSING) { continueDownload(); } } /** * 進(jìn)入應(yīng)用第一次開始下載 */ private void startDownload() { //開啟新線程，得到要下載的文件大小 new Thread() { @Override public void run() { try { HttpURLConnection conn; conn = (HttpURLConnection) new URL(DownloadActivity.url).openConnection(); conn.setConnectTimeout(5000); conn.setReadTimeout(5000); conn.setRequestMethod("GET"); conn.connect(); if (conn.getResponseCode() == 200) { Utils.Print("DownUtil連接成功"); //得到要下載的文件大小 fileSize = conn.getContentLength(); //得到文件名后綴名 String contentDisposition = new String(conn.getHeaderField("Content-Disposition").getBytes("ISO-8859-1"), "UTF-8"); String fileName = "下載測試" + contentDisposition.substring(contentDisposition.lastIndexOf("."), contentDisposition.lastIndexOf("/"")); //得到存儲路徑 String sdCardPath = context.getExternalFilesDir(null).getPath(); DownloadActivity.fileName = sdCardPath + "/" + fileName; SPUtil.getInstance(context).saveString(DownloadActivity.FILE_NAME, DownloadActivity.fileName); SPUtil.getInstance(context).saveLong(DownloadActivity.fileName, fileSize); /* * 計算一下每個線程需要分擔(dān)的下載文件大小 比如 總下載量為100 一共有三個線程 * 那么 線程1負(fù)責(zé)0-32，線程2負(fù)責(zé)33-65，線程3負(fù)責(zé)66-99和100， * 也就是說下載總量除以線程數(shù)如果有余數(shù)，那么最后一個線程多下載一個余數(shù)部分 */ //每個線程均分的大小 long threadDownSize = fileSize / DownloadActivity.threadNum; //線程均分完畢剩余的大小 long leftDownSize = fileSize % DownloadActivity.threadNum; //創(chuàng)建要寫入的文件 RandomAccessFile file = new RandomAccessFile(DownloadActivity.fileName, "rw"); //設(shè)置文件大小 file.setLength(fileSize); //關(guān)閉 file.close(); for (int i = 0; i < DownloadActivity.threadNum; i++) { Utils.Print("開啟線程" + i); //指定每個線程開始下載的位置 long startPosition = i * threadDownSize; //指定每個線程負(fù)責(zé)下載的大小，當(dāng)現(xiàn)場是集合里面最后一個線程的時候，它要增加leftDownSize的大小 threadDownSize = i == DownloadActivity.threadNum - 1 ? threadDownSize + leftDownSize : threadDownSize; //存儲線程信息 ThreadDownloadInfoBean bean = new ThreadDownloadInfoBean(DownloadThread.STATE_READY, 0, threadDownSize, startPosition + threadDownSize, startPosition, i); finalDb.save(bean); RandomAccessFile threadFile = new RandomAccessFile(DownloadActivity.fileName, "rw"); threadList.add(new DownloadThread(context, i, DownloadActivity.url, threadFile)); threadList.get(i).start(); } downloadState = STATE_LOADING; downloadInfoListener.connectSuccess(); } else { Utils.Print("DownUtil-連接失敗"); downloadInfoListener.connectFail(); } conn.disconnect(); } catch (IOException e) { Utils.Print("DownUtil-IO異常"); downloadInfoListener.IOException(); e.printStackTrace(); } } }.start(); } /** * 繼續(xù)下載 */ private void continueDownload() { List<ThreadDownloadInfoBean> list = finalDb.findAll(ThreadDownloadInfoBean.class); for (int i = 0; i < DownloadActivity.threadNum; i++) { //當(dāng)前線程已經(jīng)下載完了就不再開啟 if (list.get(i).downloadState != DownloadThread.STATE_FINISH) { Utils.Print("重新開啟線程" + i); RandomAccessFile threadFile = null; try { threadFile = new RandomAccessFile(DownloadActivity.fileName, "rw"); } catch (FileNotFoundException e) { e.printStackTrace(); } DownloadThread downloadThread = new DownloadThread(context, i, DownloadActivity.url, threadFile); threadList.add(downloadThread); downloadThread.start(); } } downloadState = STATE_LOADING; downloadInfoListener.connectSuccess(); } /** * 點擊了暫停的按鈕 */ public void clickPauseBtn() { if (downloadState == STATE_LOADING) { stopDownload(); } } /** * 暫停下載 */ private void stopDownload() { for (int i = 0; i < threadList.size(); i++) { if (threadList.get(i).downloadState == DownloadThread.STATE_LOADING) { threadList.get(i).downloadState = DownloadThread.STATE_PAUSING; } } downloadState = STATE_PAUSING; threadList.clear(); } /** * 返回此刻所有線程完成的下載大小 */ public long getFinishedSize() { long totalSize = 0; for (int i = 0; i < DownloadActivity.threadNum; i++) { ThreadDownloadInfoBean bean = MapUtil.map.get(i); if (bean != null) { //如果該線程已經(jīng)下載的部分大于分配給它的部分多余部分不予計算 long addSize = bean.downloadedSize > bean.downloadTotalSize ? bean.downloadTotalSize : bean.downloadedSize; totalSize += addSize; } } return totalSize; } /** * 下載信息監(jiān)聽器 */ private DownloadInfoListener downloadInfoListener; /** * 下載信息監(jiān)聽器 */ public interface DownloadInfoListener { void connectSuccess(); void connectFail(); void IOException(); } /** * 設(shè)置下載信息監(jiān)聽器 */ public void setDownloadInfoListener(DownloadInfoListener downloadInfoListener) { this.downloadInfoListener = downloadInfoListener; } }頁面Activity：負(fù)責(zé)展示下載進(jìn)度等信息，提供操作頁面
public class DownloadActivity extends BaseActivity { /** * 下載地址輸入框 */ private EditText et_download_url; /** * 確定輸入地址的按鈕 */ private Button btn_download_geturl; /** * 進(jìn)度條 */ private NumberProgressView np_download; /** * 開始下載的按鈕 */ private Button btn_download_start; /** * 暫停下載的按鈕 */ private Button btn_download_pause; /** * 取消下載的按鈕 */ private Button btn_download_cancel; /** * 文件信息顯示 */ private TextView tv_download_file_info; /** * 下載速度顯示 */ private TextView tv_download_speed; /** * 顯示下載信息 */ private TextView tv_download_speed_info; /** * 每隔一段時間刷新下載進(jìn)度顯示 */ private final static int WHAT_INCREACE = 1; /** * 得到了文件名稱 */ private final static int WHAT_GET_FILENAME = 2; /** * downUtil連接失敗 */ private final static int WHAI_CONNECT_FAIL = 3; /** * downUtilIO異常 */ private final static int WHAT_IO_EXCEPTION = 4; /** * 下載工具 */ private DownUtil downUtil; /** * 需要開啟的線程數(shù)量 */ public static final int threadNum = 5; /** * 存放文件路徑名稱的SP鍵名 */ public static final String FILE_NAME = "fileName"; /** * 要下載的文件的url地址 */ public static String url = ""; /** * 文件下載路徑和文件名稱 */ public static String fileName; /** * 上次統(tǒng)計已經(jīng)完成下載的文件大小 */ private long lastFinishedSize; private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case WHAT_INCREACE: updateView(); break; case WHAT_GET_FILENAME: tv_download_file_info.setText("下載路徑：" + fileName); break; case WHAI_CONNECT_FAIL: tv_download_file_info.setText("連接失敗"); break; case WHAT_IO_EXCEPTION: tv_download_file_info.setText("IO異常"); break; } } }; /** * 更新視圖 */ private void updateView() { //當(dāng)前已經(jīng)完成下載的文件大小 long currentFinishedSize = downUtil.getFinishedSize(); //要顯示的下載信息的文字 StringBuilder downloadInfo = new StringBuilder(); tv_download_speed.setText("當(dāng)前下載速度：" + formateSize(currentFinishedSize - lastFinishedSize) + "/s"); //本次統(tǒng)計比上次統(tǒng)計增加了，更新視圖,本次統(tǒng)計較上次統(tǒng)計沒有變化，不做視圖更新 if (currentFinishedSize > lastFinishedSize) { lastFinishedSize = currentFinishedSize; downloadInfo.append("下載進(jìn)度：" + formateSize(currentFinishedSize) + "/" + formateSize(downUtil.fileSize) + "/n"); for (int i = 0; i < threadNum; i++) { ThreadDownloadInfoBean bean = MapUtil.map.get(i); if (bean.downloadTotalSize != 0) { downloadInfo.append("線程" + i + "下載進(jìn)度:" + bean.downloadedSize * 100 / bean.downloadTotalSize + "% " + formateSize(bean.downloadedSize) + "/" + formateSize(bean.downloadTotalSize) + "/n"); } } np_download.setProgress((int) (currentFinishedSize * 100 / downUtil.fileSize)); tv_download_speed_info.setText(downloadInfo); //下載完成后 if (currentFinishedSize >= downUtil.fileSize) { tv_download_speed.setText("下載完畢"); handler.removeMessages(WHAT_INCREACE); return; } } handler.sendEmptyMessageDelayed(WHAT_INCREACE, 1000); } /** * 返回子類要顯示的布局 R.layout...... */ @Override protected int childView() { return R.layout.activity_download; } /** * 強制子類實現(xiàn)該抽象方法，初始化各自的View */ @Override protected void findChildView() { et_download_url = (EditText) findViewById(R.id.et_download_url); btn_download_geturl = (Button) findViewById(R.id.btn_download_geturl); np_download = (NumberProgressView) findViewById(R.id.np_download); btn_download_start = (Button) findViewById(R.id.btn_download_start); btn_download_pause = (Button) findViewById(R.id.btn_download_pause); btn_download_cancel = (Button) findViewById(R.id.btn_download_cancel); tv_download_file_info = (TextView) findViewById(R.id.tv_download_file_info); tv_download_speed = (TextView) findViewById(R.id.tv_download_speed); tv_download_speed_info = (TextView) findViewById(R.id.tv_download_speed_info); } /** * 強制子類實現(xiàn)該抽象方法，初始化各自數(shù)據(jù) */ @Override protected void initChildData() { downUtil = new DownUtil(this); lastFinishedSize = downUtil.getFinishedSize(); StringBuilder downloadInfo = new StringBuilder(); fileName = SPUtil.getInstance(this).getString(FILE_NAME, null); if (fileName != null) { downloadInfo.append("下載路徑：" + fileName); if (downUtil.downloadState == DownUtil.STATE_FINISH) { np_download.setProgress(100); } else if (downUtil.downloadState == DownUtil.STATE_PAUSING) { np_download.setProgress((int) (downUtil.getFinishedSize() * 100 / downUtil.fileSize)); } tv_download_file_info.setText(downloadInfo); } } /** * 強制子類實現(xiàn)該抽象方法，設(shè)置自己的監(jiān)聽器 */ @Override protected View[] setChildListener() { downUtil.setDownloadInfoListener(new DownUtil.DownloadInfoListener() { @Override public void connectSuccess() { //不能在此更新，需要到主線程刷新UI handler.sendEmptyMessage(WHAT_GET_FILENAME); handler.sendEmptyMessage(WHAT_INCREACE); } @Override public void connectFail() { handler.sendEmptyMessage(WHAI_CONNECT_FAIL); } @Override public void IOException() { handler.sendEmptyMessage(WHAT_IO_EXCEPTION); } }); return new View[]{btn_download_start, btn_download_pause, btn_download_geturl, btn_download_cancel}; } /** * 子類在這個方法里面實現(xiàn)自己View的點擊監(jiān)聽事件的相應(yīng) * * @param v 父類傳遞到子類的點擊的View */ @Override protected void clickChildView(View v) { switch (v.getId()) { case R.id.btn_download_start: downUtil.clickDownloadBtn(); break; case R.id.btn_download_pause: downUtil.clickPauseBtn(); handler.removeMessages(WHAT_INCREACE); break; case R.id.btn_download_cancel: //停止發(fā)送消息 handler.removeMessages(WHAT_INCREACE); //暫停下載 downUtil.clickPauseBtn(); //重置狀態(tài) downUtil.downloadState = DownUtil.STATE_READY; //統(tǒng)計下載的大小歸零 lastFinishedSize = 0; //重置文本信息 tv_download_speed.setText(""); tv_download_file_info.setText(""); tv_download_speed_info.setText(""); //進(jìn)度條歸零 np_download.setProgress(0); //清空內(nèi)存數(shù)據(jù) MapUtil.map.clear(); //sp清理 SPUtil.getInstance(this).removeAll(); //清空數(shù)據(jù)庫 downUtil.finalDb.deleteAll(ThreadDownloadInfoBean.class); //刪除文件 if (fileName != null) { File file = new File(fileName); if (file.exists()) { boolean delete = file.delete(); if (delete) { Utils.ToastS(this, "刪除" + fileName + "成功"); } else { Utils.ToastS(this, "刪除失敗"); } } else { Utils.ToastS(this, "文件不存在"); } } else { Utils.ToastS(this, "文件不存在"); } break; case R.id.btn_download_geturl: String editTextUrl = et_download_url.getText().toString(); if (editTextUrl.trim().equals("")) { Utils.ToastS(this, "請輸入地址"); } else { url = editTextUrl; } break; } } @Override protected void onDestroy() { handler.removeCallbacksAndMessages(null); downUtil.clickPauseBtn(); super.onDestroy(); } /** * 格式化數(shù)據(jù)大小 */ private String formateSize(long size) { return Formatter.formatFileSize(this, size); } }布局
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="com.example.testdemo.activity.DownloadActivity"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <EditText android:id="@+id/et_download_url" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:hint="輸入下載地址"/> <Button android:id="@+id/btn_download_geturl" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="確定"/> </LinearLayout> <com.example.testdemo.view.NumberProgressView android:id="@+id/np_download" android:layout_width="match_parent" android:layout_height="100dp"> </com.example.testdemo.view.NumberProgressView> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:id="@+id/btn_download_start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="開始下載"/> <Button android:id="@+id/btn_download_pause" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="暫停下載"/> <Button android:id="@+id/btn_download_cancel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="取消下載"/> </LinearLayout> <TextView android:id="@+id/tv_download_file_info" android:layout_width="match_parent" android:layout_height="wrap_content"/> <TextView android:id="@+id/tv_download_speed" android:layout_width="match_parent" android:layout_height="wrap_content"/> <TextView android:id="@+id/tv_download_speed_info" android:layout_width="match_parent" android:layout_height="wrap_content"/> </LinearLayout>
下載Activity的父類
public abstract class BaseActivity extends Activity { /** * 點擊監(jiān)聽器,子類也可以使用 */ protected BaseOnClickListener onClickListener = new BaseOnClickListener(); /** * 在onCreate方法里面，找到視圖，初始化數(shù)據(jù)，設(shè)置點擊監(jiān)聽器 */ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(childView()); findView(); initData(); setListener(); } /** * 返回子類要顯示的布局 R.layout...... */ protected abstract int childView(); /** * 找到需要的視圖---網(wǎng)址：https://www.buzzingandroid.com/tools/android-layout-finder/ */ private void findView() { findChildView(); } /** * 初始化數(shù)據(jù) */ private void initData() { // 初始化子類的數(shù)據(jù) initChildData(); } /** * 對需要設(shè)置監(jiān)聽 的視圖設(shè)置監(jiān)聽 */ private void setListener() { // 子類實現(xiàn)setChildListene()方法，返回一個View數(shù)組，里面包含所有需要設(shè)置點擊監(jiān)聽的View,然后進(jìn)行For循環(huán)，對里面所有View設(shè)置監(jiān)聽器 if (setChildListener() == null || setChildListener().length == 0) { return; } View[] viewArray = setChildListener(); for (View view : viewArray) { view.setOnClickListener(onClickListener); } } /** * 自定義的點擊監(jiān)聽類 */ protected class BaseOnClickListener implements View.OnClickListener { @Override public void onClick(View v) { clickChildView(v); } } /** * 強制子類實現(xiàn)該抽象方法，初始化各自的View */ protected abstract void findChildView(); /** * 強制子類實現(xiàn)該抽象方法，初始化各自數(shù)據(jù) */ protected abstract void initChildData(); /** * 強制子類實現(xiàn)該抽象方法，設(shè)置自己的監(jiān)聽器 */ protected abstract View[] setChildListener(); /** * 子類在這個方法里面實現(xiàn)自己View的點擊監(jiān)聽事件的相應(yīng) * * @param v 父類傳遞到子類的點擊的View */ protected abstract void clickChildView(View v); }得到數(shù)據(jù)庫的操作類
public class DBUtil { public static FinalDb getFinalDb(final Context context) { FinalDb finalDb = FinalDb.create(context, "REMUXING.db", false, 1, new FinalDb.DbUpdateListener() { @Override public void onUpgrade(SQLiteDatabase db, int oldVirsion, int newVirsion) { } }); return finalDb; }}內(nèi)存中存儲下載信息的類
public class MapUtil { public static HashMap<Integer, ThreadDownloadInfoBean> map = new HashMap<>();}SP存儲的工具類
public enum SPUtil { SPUTIL; public static final String NOTIFICATIONBAR_HEIGHT = "notificationbar_height"; private static SharedPreferences sp; public static SPUtil getInstance(Context context) { if (sp == null) { sp = context.getSharedPreferences("REMUXING", Context.MODE_PRIVATE); } return SPUTIL; } public void saveLong(String key, Long value) { sp.edit().putLong(key, value).apply(); } public Long getLong(String key, Long defValue) { return sp.getLong(key, defValue); } public void saveString(String key, String value) { sp.edit().putString(key, value).apply(); } public String getString(String key, String defValue) { return sp.getString(key, defValue); } public void removeAll() { sp.edit().clear().apply(); } }工具類
public class Utils { /** * 打印 */ public static void Print(String message) { Log.e("TAG", "----- " + message + " ------") ; } /** * 短吐司 */ public static void ToastS(Context context, String message) { Toast.makeText(context, message, Toast.LENGTH_SHORT).show(); }}進(jìn)度條：這個可以忽略，用安卓原生的，代碼看我的另一篇博客：Android自定義View實現(xiàn)水平帶數(shù)字百分比進(jìn)度條
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