下载更新APK - litonghui/TechBlog GitHub Wiki

public class AppUpdateService extends Service { // 标题 private int titleId = 0;

// 文件存储
private File updateDir = null;
private File updateFile = null;
// 下载状态
private final static int DOWNLOAD_COMPLETE = 0;
private final static int DOWNLOAD_FAIL = 1;
// 通知栏
private NotificationManager updateNotificationManager = null;
private Notification updateNotification = null;
// 通知栏跳转Intent
private Intent updateIntent = null;
private PendingIntent updatePendingIntent = null;
/***
 * 创建通知栏
 */
RemoteViews contentView;
// 这样的下载代码很多，我就不做过多的说明
int downloadCount = 0;
int currentSize = 0;
long totalSize = 0;
int updateTotalSize = 0;

// 在onStartCommand()方法中准备相关的下载工作：
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
	// 获取传值
	titleId = intent.getIntExtra("titleId", 0);
	// 创建文件
	if (android.os.Environment.MEDIA_MOUNTED.equals(android.os.Environment
			.getExternalStorageState())) {
		updateDir = new File(Environment.getExternalStorageDirectory(),
				APIURL.saveFileName);
		updateFile = new File(updateDir.getPath(), getResources()
				.getString(titleId) + ".apk");
	}

	this.updateNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
	this.updateNotification = new Notification();

	// 设置下载过程中，点击通知栏，回到主界面
	updateIntent = new Intent(this, MainActivity.class);
	updatePendingIntent = PendingIntent.getActivity(this, 0, updateIntent,
			0);
	// 设置通知栏显示内容
	updateNotification.icon = R.drawable.ic_launcher;
	updateNotification.tickerText = "开始下载";
	updateNotification.setLatestEventInfo(this, "指读", "0%",
			updatePendingIntent);
	// 发出通知
	updateNotificationManager.notify(0, updateNotification);

	// 开启一个新的线程下载，如果使用Service同步下载，会导致ANR问题，Service本身也会阻塞
	new Thread(new updateRunnable()).start();// 这个是下载的重点，是下载的过程

	return super.onStartCommand(intent, flags, startId);
}

@Override
public IBinder onBind(Intent arg0) {
	// TODO Auto-generated method stub
	return null;
}

private Handler updateHandler = new Handler() {
	@Override
	public void handleMessage(Message msg) {
		switch (msg.what) {
			
		case DOWNLOAD_COMPLETE:
			// 点击安装PendingIntent
			Uri uri = Uri.fromFile(updateFile);
			Intent installIntent = new Intent(Intent.ACTION_VIEW);
			installIntent.setDataAndType(uri,
					"application/vnd.android.package-archive");

			updatePendingIntent = PendingIntent.getActivity(
					AppUpdateService.this, 0, installIntent, 0);

			updateNotification.defaults = Notification.DEFAULT_SOUND;// 铃声提醒
			updateNotification.setLatestEventInfo(AppUpdateService.this,
					"指读", "下载完成,点击安装。", updatePendingIntent);
			updateNotificationManager.notify(0, updateNotification);

			// 停止服务
			stopService(updateIntent);
		case DOWNLOAD_FAIL:
			// 下载失败
			updateNotification.setLatestEventInfo(AppUpdateService.this,
					"指读", "下载完成,点击安装。", updatePendingIntent);
			updateNotificationManager.notify(0, updateNotification);
		default:
			stopService(updateIntent);
		}
	}
};

public long downloadUpdateFile(String downloadUrl, File saveFile)
		throws Exception {

	HttpURLConnection httpConnection = null;
	InputStream is = null;
	FileOutputStream fos = null;

	try {
		URL url = new URL(downloadUrl);
		httpConnection = (HttpURLConnection) url.openConnection();
		httpConnection
				.setRequestProperty("User-Agent", "PacificHttpClient");
		if (currentSize > 0) {
			httpConnection.setRequestProperty("RANGE", "bytes="
					+ currentSize + "-");
		}
		httpConnection.setConnectTimeout(10000);
		httpConnection.setReadTimeout(20000);
		updateTotalSize = httpConnection.getContentLength();
		if (httpConnection.getResponseCode() == 404) {
			throw new Exception("fail!");
		}
		is = httpConnection.getInputStream();
		fos = new FileOutputStream(saveFile, false);
		byte buffer[] = new byte[4096];
		int readsize = 0;
		while ((readsize = is.read(buffer)) > 0) {
			fos.write(buffer, 0, readsize);
			totalSize += readsize;
			// 为了防止频繁的通知导致应用吃紧，百分比增加10才通知一次
			if ((downloadCount == 0)
					|| (int) (totalSize * 100 / updateTotalSize) - 10 > downloadCount) {
				downloadCount += 10;

				updateNotification.setLatestEventInfo(AppUpdateService.this,
						"正在下载", (int) totalSize * 100 / updateTotalSize
								+ "%", updatePendingIntent);

				
				/***
				 * 在这里我们用自定的view来显示Notification
				 */
				updateNotification.contentView = new RemoteViews(
						getPackageName(), R.layout.notification_item);
				updateNotification.contentView.setTextViewText(
						R.id.notificationTitle, "正在下载");
				updateNotification.contentView.setProgressBar(
						R.id.notificationProgress, 100, downloadCount, false);
				
				updateNotificationManager.notify(0, updateNotification);
			}
		}
	} finally {
		if (httpConnection != null) {
			httpConnection.disconnect();
		}
		if (is != null) {
			is.close();
		}
		if (fos != null) {
			fos.close();
		}
	}
	return totalSize;
}

class updateRunnable implements Runnable {
	Message message = updateHandler.obtainMessage();

	public void run() {
		message.what = DOWNLOAD_COMPLETE;
		
		
		try {
			// 增加权限<USES-PERMISSION
			// android:name="android.permission.WRITE_EXTERNAL_STORAGE">;
			if (!updateDir.exists()) {
				updateDir.mkdirs();
			}
			if (!updateFile.exists()) {
				updateFile.createNewFile();
			}
			// 下载函数，以QQ为例子
			// 增加权限<USES-PERMISSION
			// android:name="android.permission.INTERNET">;
			long downloadSize = downloadUpdateFile(
					Conf.DOWNLOAD_APK,
					
					updateFile);
			if (downloadSize > 0) {
				// 下载成功
				updateHandler.sendMessage(message);
			} 
		} catch (Exception ex) {
			ex.printStackTrace();
			message.what = DOWNLOAD_FAIL;
			// 下载失败
			updateHandler.sendMessage(message);
		}
	}
}

}