android - Android-不断检查数据库中的新记录并生成通知，提供新条目的详细信息

Question

我正在尝试创建一个 android 应用程序，该应用程序不断检查远程数据库中的新记录，并在添加新记录时提供通知。我想对添加的每条记录重复此操作。

到目前为止，我已经完成了以下操作创建了一个从数据库中获取数据的服务。任何人都可以建议在固定间隔后一次又一次地调用服务的最佳方法，或者保持服务正常运行并重复调用方法。什么会证明更好的表现？

score 1 · Accepted Answer

不断检查远程数据库中的新记录将在您的应用程序中产生负载。

您可以使用 Google Cloud 到设备消息服务。每次远程数据库有新记录时，这都会向设备发送通知消息。

请检查：http: //developer.android.com/google/gcm/index.html

GCM 的步骤

1.在AndroidManifest.xml中添加以下权限和接收者

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />

<permission android:name="com.example.test.permission.C2D_MESSAGE" 
    android:protectionLevel="signature" />
<uses-permission android:name="com.example.test.permission.C2D_MESSAGE" />

 <receiver
        android:name="com.example.test.MyBroadcastReceiver"
        android:permission="com.google.android.c2dm.permission.SEND" >
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
            <category android:name="com.example.test" />
        </intent-filter>
    </receiver>

注意：查找并替换 com.example.test 为您的包名称

MyBroadcastReceiver.java

public class MyBroadcastReceiver extends BroadcastReceiver{

    private static final String TAG = "GCM";
    MyPrefs myPrefs ;

@Override
public void onReceive(Context context, Intent intent) {

myPrefs = new MyPrefs(context);

Log.d(TAG,"inside onReceive");

String action = intent.getAction();
if (action.equals("com.google.android.c2dm.intent.REGISTRATION")) {

    handleRegistration(context,intent);
} else if (action.equals("com.google.android.c2dm.intent.RECEIVE")) {


    handleMessage(context,intent);
}
}
private void handleRegistration(Context context,Intent intent) {
String registrationId = intent.getStringExtra("registration_id");
String error = intent.getStringExtra("error");
String unregistered = intent.getStringExtra("unregistered");       

// registration succeeded
if (registrationId != null) {
    Log.d(TAG, "Device_reg_id : "+registrationId);

    // store registration ID on shared preferences
    myPrefs.putString("DEVICE_REG_ID", registrationId);

    // notify 3rd-party server about the registered ID
    generateNotification(context, "Registration Sucessful", "Device register sucessfully!");
}

// unregistration succeeded
if (unregistered != null) {
    // get old registration ID from shared preferences
    // notify 3rd-party server about the unregistered ID
} 

// last operation (registration or unregistration) returned an error;
if (error != null) {
    if ("SERVICE_NOT_AVAILABLE".equals(error)) {
        // optionally retry using exponential back-off
        // (see Advanced Topics)
    } else {
        // Unrecoverable error, log it
        Log.i(TAG, "Received error: " + error);
    }
}
}
private void handleMessage(Context context, Intent intent) {

String data = intent.getExtras().getString("data");
generateNotification(context, "New Message is received", data);
}

private void generateNotification(Context context,String title,String text) {

NotificationCompat.Builder mBuilder = 
        new NotificationCompat.Builder(context)
        .setSmallIcon(R.drawable.ic_launcher)
        .setContentTitle(title)
        .setContentText(text);

// Creates an explicit intent for an Activity in your app
Intent resultIntent = new Intent(context, MainActivity.class);

PendingIntent resultPendingIntent = PendingIntent.getBroadcast(context,0,resultIntent, 0);     
mBuilder.setContentIntent(resultPendingIntent);

NotificationManager mNotificationManager =
    (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
// mId allows you to update the notification later on.
mNotificationManager.notify(0, mBuilder.build());
 }

MainActivity.java

public class MainActivity extends Activity {

 String device_reg_id;

 @Override
 public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

MyPrefs prefs = new MyPrefs(this);
device_reg_id = prefs.getString("DEVICE_REG_ID"); 

if (device_reg_id == null )
{
    Log.d("GCM", "Registration start");
    // registration 
    Intent registrationIntent = new Intent("com.google.android.c2dm.intent.REGISTER");
    // sets the app name in the intent
    registrationIntent.putExtra("app", PendingIntent.getBroadcast(this, 0, new Intent(), 0));
    registrationIntent.putExtra("sender", "1850XXXX2785");
    startService(registrationIntent);
}else
{
    // send a message to device its self

        String api_key = "AIzaSyBXSJHPqFiYeYdAoYfN1XlI20Es";

        Sender sender = new Sender(api_key);

        Message message = new Message.Builder()
        .collapseKey("1")
        .timeToLive(3)
        .delayWhileIdle(true)
        .addData("data", "Welcome!")
        .build();

        Result result;
        try {
            result = sender.send(message, device_reg_id, 5);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
      }
    }
  }

MyPrefs.java

public class MyPrefs {

 private SharedPreferences sp;
 private Editor editor;

 public MyPrefs(Context context){
        sp = PreferenceManager.getDefaultSharedPreferences(context);
        editor = sp.edit();
 }
public void putString(String key,String Value){
          editor.putString(key,Value);
          editor.commit();
}
public String getString(String key){
       return sp.getString(key,null);
 }
}

注意不要忘记从 sdk\extras\google\gcm\gcm-server\dist导入gcm-server.jar 。如果您在 sdk 中找不到路径，则在 Android SDK Manager 的 Extras 下安装 Google Cloud Messaging for Android Libaray

android - Android-不断检查数据库中的新记录并生成通知，提供新条目的详细信息

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