如何簡單實現安卓app自動更新功能

接下最後我們來看下服務吧UpdateService .java:

/**
 * 不要忘記注冊，在mainfest文件中
*/
public class UpdateService extends Service {
    // BT字節參考量
    private static final float SIZE_BT = 1024L;
    // KB字節參考量
    private static final float SIZE_KB = SIZE_BT * 1024.0f;
    // MB字節參考量
    private static final float SIZE_MB = SIZE_KB * 1024.0f;

    private final static int DOWNLOAD_COMPLETE = 1;// 完成
    private final static int DOWNLOAD_NOMEMORY = -1;// 內存異常
    private final static int DOWNLOAD_FAIL = -2;// 失敗

    private String appName = null;// 應用名字
    private String appUrl = null;// 應用升級地址
    private File updateDir = null;// 文件目錄
    private File updateFile = null;// 升級文件

    // 通知欄
    private NotificationManager updateNotificationManager = null;
    private Notification updateNotification = null;

    private Intent updateIntent = null;// 下載完成
    private PendingIntent updatePendingIntent = null;// 在下載的時候

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
        appName = intent.getStringExtra("appname");
        appUrl = intent.getStringExtra("appurl");
        updateNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        updateNotification = new Notification();
        //通知圖標
        updateNotification.icon = R.mipmap.head;
        //通知信息描述
        updateNotification.tickerText = "正在下載 " + appName;
        updateNotification.when = System.currentTimeMillis();
        updateIntent = new Intent(this, MyApplication.class);
        updatePendingIntent = PendingIntent.getActivity(this, 0, updateIntent,
                0);
        updateNotification.contentIntent = updatePendingIntent;
        updateNotification.contentIntent.cancel();
        updateNotification.contentView = new RemoteViews(getPackageName(),
                //這個布局很簡單，就是一個圖片和兩個textview，分別是正在下載和下載進度
                R.layout.download_notification);
        updateNotification.contentView.setTextViewText(
                R.id.download_notice_name_tv, appName + " 正在下載");
        updateNotification.contentView.setTextViewText(
                R.id.download_notice_speed_tv, "0MB (0%)");
        updateNotificationManager.notify(0, updateNotification);
        new UpdateThread().execute();
    }

    /**
     * 在這裡使用了asynctask異步任務來下載
     */
    class UpdateThread extends AsyncTask {
        @Override
        protected Integer doInBackground(Void... params) {
            return downloadUpdateFile(appUrl);
        }

        @Override
        protected void onPostExecute(Integer result) {
            super.onPostExecute(result);

            if (result == DOWNLOAD_COMPLETE) {
                Log.d("update", "下載成功");
                String cmd = "chmod 777 " + updateFile.getPath();
                try {
                    Runtime.getRuntime().exec(cmd);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Uri uri = Uri.fromFile(updateFile);
                //安裝程序
                Intent installIntent = new Intent(Intent.ACTION_VIEW);
                installIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                installIntent.setDataAndType(uri,
                        "application/vnd.android.package-archive");
                updatePendingIntent = PendingIntent.getActivity(
                        UpdateService.this, 0, installIntent, 0);
                updateNotification.contentIntent = updatePendingIntent;
                updateNotification.contentView.setTextViewText(
                        R.id.download_notice_speed_tv,
                        getString(R.string.update_notice_finish));
                updateNotification.tickerText = appName + "下載完成";
                updateNotification.when = System.currentTimeMillis();
                updateNotification.defaults = Notification.DEFAULT_SOUND;
                updateNotification.flags |= Notification.FLAG_AUTO_CANCEL;
                updateNotificationManager.notify(0, updateNotification);
                //啟動安裝程序
                UpdateService.this.startActivity(installIntent);
                stopSelf();
            } else if (result == DOWNLOAD_NOMEMORY) {
                //如果內存有問題
                updateNotification.tickerText = appName + "下載失敗";
                updateNotification.when = System.currentTimeMillis();
                updateNotification.contentView.setTextViewText(
                        R.id.download_notice_speed_tv,
                        getString(R.string.update_notice_nomemory));
                updateNotification.flags |= Notification.FLAG_AUTO_CANCEL;
                updateNotification.defaults = Notification.DEFAULT_SOUND;
                updateNotificationManager.notify(0, updateNotification);
                stopSelf();
            } else if (result == DOWNLOAD_FAIL) {
                //下載失敗
                updateNotification.tickerText = appName + "下載失敗";
                updateNotification.when = System.currentTimeMillis();
                updateNotification.contentView.setTextViewText(
                        R.id.download_notice_speed_tv,
                        getString(R.string.update_notice_error));
                updateNotification.flags |= Notification.FLAG_AUTO_CANCEL;
                updateNotification.defaults = Notification.DEFAULT_SOUND;
                updateNotificationManager.notify(0, updateNotification);
                stopSelf();
            }
        }

    }

    /**
     * 下載更新程序文件
     * @param downloadUrl   下載地址
     * @return
     */
    private int downloadUpdateFile(String downloadUrl) {
        int count = 0;
        long totalSize = 0;   //總大小
        long downloadSize = 0;   //下載的大小
        URI uri = null;

        //這個已經捨棄了，要用的話，就要加上org.apache.http.legacy.jar這個jar包
        HttpGet httpGet = null;
        try {
            uri = new URI(downloadUrl);
            httpGet = new HttpGet(uri);
        } catch (URISyntaxException e) {
            String encodedUrl = downloadUrl.replace(' ', '+');
            httpGet = new HttpGet(encodedUrl);
            e.printStackTrace();
        }
        HttpClient httpClient = new DefaultHttpClient();
        HttpResponse httpResponse = null;
        FileOutputStream fos = null;
        InputStream is = null;
        try {
            httpResponse = httpClient.execute(httpGet);
            if (httpResponse != null) {
                int stateCode = httpResponse.getStatusLine().getStatusCode();
                if (stateCode == HttpStatus.SC_OK) {
                    HttpEntity entity = httpResponse.getEntity();
                    if (entity != null) {
                        totalSize = entity.getContentLength();
                        //如果內存可用
                        if (MemoryAvailable(totalSize)) {
                            is = entity.getContent();
                            if (is != null) {
                                fos = new FileOutputStream(updateFile, false);
                                byte buffer[] = new byte[4096];
                                int readsize = 0;
                                while ((readsize = is.read(buffer)) > 0) {
                                    fos.write(buffer, 0, readsize);
                                    downloadSize += readsize;
                                    if ((count == 0)
                                            || (int) (downloadSize * 100 / totalSize) >= count) {
                                        count += 5;
                                        updateNotification.contentView
                                                .setTextViewText(
                                                        R.id.download_notice_speed_tv,
                                                        getMsgSpeed(downloadSize,totalSize));
                                        updateNotificationManager.notify(0,
                                                updateNotification);
                                    }
                                }
                                fos.flush();
                                if (totalSize >= downloadSize) {
                                    return DOWNLOAD_COMPLETE;
                                } else {
                                    return DOWNLOAD_FAIL;
                                }
                            }
                        } else {
                            if (httpGet != null) {
                                httpGet.abort();
                            }
                            return DOWNLOAD_NOMEMORY;
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (fos != null) {
                    fos.close();
                }
                if (is != null) {
                    is.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (httpClient != null) {
                httpClient.getConnectionManager().shutdown();
            }
        }
        return DOWNLOAD_FAIL;
    }

    /**
     * 可用內存大小
     * @param fileSize
     * @return
     */
    private boolean MemoryAvailable(long fileSize) {
        fileSize += (1024 << 10);
        if (MemoryStatus.externalMemoryAvailable()) {
            if ((MemoryStatus.getAvailableExternalMemorySize() <= fileSize)) {
                if ((MemoryStatus.getAvailableInternalMemorySize() > fileSize)) {
                    createFile(false);
                    return true;
                } else {
                    return false;
                }
            } else {
                createFile(true);
                return true;
            }
        } else {
            if (MemoryStatus.getAvailableInternalMemorySize() <= fileSize) {
                return false;
            } else {
                createFile(false);
                return true;
            }
        }
    }

    /**
     * 獲取下載進度
     * @param downSize
     * @param allSize
     * @return
     */
    public static String getMsgSpeed(long downSize, long allSize) {
        StringBuffer sBuf = new StringBuffer();
        sBuf.append(getSize(downSize));
        sBuf.append("/");
        sBuf.append(getSize(allSize));
        sBuf.append(" ");
        sBuf.append(getPercentSize(downSize, allSize));
        return sBuf.toString();
    }

    /**
     * 獲取大小
     * @param size
     * @return
     */
    public static String getSize(long size) {
        if (size >= 0 && size < SIZE_BT) {
            return (double) (Math.round(size * 10) / 10.0) + "B";
        } else if (size >= SIZE_BT && size < SIZE_KB) {
            return (double) (Math.round((size / SIZE_BT) * 10) / 10.0) + "KB";
        } else if (size >= SIZE_KB && size < SIZE_MB) {
            return (double) (Math.round((size / SIZE_KB) * 10) / 10.0) + "MB";
        }
        return "";
    }

    /**
     * 獲取到當前的下載百分比
     * @param downSize   下載大小
     * @param allSize    總共大小
     * @return
     */
    public static String getPercentSize(long downSize, long allSize) {
        String percent = (allSize == 0 ? "0.0" : new DecimalFormat("0.0")
                .format((double) downSize / (double) allSize * 100));
        return "(" + percent + "%)";
    }


    /**
     * 創建file文件
     * @param sd_available    sdcard是否可用
     */
    private void createFile(boolean sd_available) {
        if (sd_available) {
            updateDir = new File(Environment.getExternalStorageDirectory(),
                    UpdateInformation.downloadDir);
        } else {
            updateDir = getFilesDir();
        }
        updateFile = new File(updateDir.getPath(), appName + ".apk");
        if (!updateDir.exists()) {
            updateDir.mkdirs();
        }
        if (!updateFile.exists()) {
            try {
                updateFile.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            updateFile.delete();
            try {
                updateFile.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}