I would suggest ORMlite its open source freeware &amp; has good documentation also it support java as well as android. 

It has good developer support &amp; many application running on ORMlite (Including I have developed :) ).

check this [comparison][1] of ORMLite &amp; Green DAO for your referance.


  [1]: http://software-workshop.eu/content/comparing-android-orm-libraries-greendao-vs-ormlite

A difference between ORMLite and GreenDAO is the usage of annotations. While ORMLite uses Annotations, GreenDAO does not, as described [here][1]. 

Annotations used by ORMLite rely on reflection, which might impact performance especially on slower Android devices in a negative way. Would be interesting to see benchmarks comparing ORMLite and GreenDAO.

  [1]: http://greendao-orm.com/documentation/faq/

One issue I have with a number of the libraries that I&#39;ve used is that they require that their initialization take place in android.app.Application.onCreate().  I prefer that libraries allow me to do their initialization in a secondary thread, in a service, or after I have finished displaying the user interface.

I believe that Active Android has this &#39;problem&#39;, and ORMLite does not.  I&#39;m not sure about GreenDAO.

Whether it is really a problem depends on your application, but I will note that [the docs for onCreate()](http://developer.android.com/reference/android/app/Application.html#onCreate%28%29) say &quot;Implementations should be as quick as possible (for example using lazy initialization of state) since the time spent in this function directly impacts the performance of starting the first activity, service, or receiver in a process.&quot;

Unrelated to that, I note that ActiveAndroid uses annotations, like ORMlite, but unlike GreenDAO which uses code generation.

There is a relatively-new lightweight JVM called [Avian][1] that can produce executables for iOS targets.

There isn&#39;t too much documentation on the website (and not much can be found searching with Google). I was wondering if anybody was aware of a step-by-step tutorial on how to get a basic Scala program running on iOS, using [Avian][1].


  [1]: http://oss.readytalk.com/avian/

Scala on iOS using Avian

I have a solution initially created using VS2010. When I opened it using VS 2012, it asked me to do some conversion, which I agreed. Now I&#39;m using VS 2010 to open the solution again, and when I tried to build it gave an error:

&gt;error MSB8008: Specified platform toolset (v110) is not installed or invalid. Please make sure that a supported PlatformToolset value is selected

How can I fix it? For example, is there a way to change the `platform toolset` to v100 again?

Specified platform toolset (v110) is not installed

Which is the best ORM tool available for Android? 

I am seeing ORMlite and ActiveAndroid are the most discussed across and a friend of mine suggested me to use GreenDAO. So looking for some knowledge resource which can help me in Decision Making?

Features I am looking to judge are freely available (open source), good documentation, active forums, stable version available, etc, which ever required for developer.




Green DAO vs ORM lite vs Active Android

Which is the best ORM tool available for Android?
I am seeing ORMlite and ActiveAndroid are the most discussed across and a friend of mine suggested me to use GreenDAO. So looking for some knowledge resource which can help me in Decision Making?
Features I am looking to judge are freely available (open source), good documentation, active forums, stable version available, etc, which ever required for developer.

I&#39;m testing out the new Google Maps API V2 for Android, and I&#39;m getting this message when the app launches:

![MainActivity showing error message][1]

*This is running on an 4.1 emulator.*

Here is my `AndroidManifest.xml` file:

    &lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        package=&quot;com.example.maptest&quot;
        android:versionCode=&quot;1&quot;
        android:versionName=&quot;1.0&quot; &gt;

        &lt;uses-sdk
            android:minSdkVersion=&quot;8&quot;
            android:targetSdkVersion=&quot;15&quot; /&gt;

        &lt;permission
            android:name=&quot;com.example.maptest.permission.MAPS_RECEIVE&quot;
            android:protectionLevel=&quot;signature&quot;/&gt;
        &lt;uses-permission android:name=&quot;com.example.maptest.permission.MAPS_RECEIVE&quot;/&gt;
        &lt;uses-permission android:name=&quot;com.google.android.providers.gsf.permission.READ_GSERVICES&quot;/&gt;
        &lt;uses-permission android:name=&quot;android.permission.INTERNET&quot;/&gt;
        &lt;uses-permission android:name=&quot;android.permission.WRITE_EXTERNAL_STORAGE&quot;/&gt;
        &lt;uses-permission android:name=&quot;android.permission.ACCESS_COARSE_LOCATION&quot;/&gt;
        &lt;uses-permission android:name=&quot;android.permission.ACCESS_FINE_LOCATION&quot;/&gt;

        &lt;!-- Require OpenGL ES version 2 --&gt;
        &lt;uses-feature
              android:glEsVersion=&quot;0x00020000&quot;
              android:required=&quot;true&quot;/&gt;

        &lt;application
            android:icon=&quot;@drawable/ic_launcher&quot;
            android:label=&quot;@string/app_name&quot;
            android:theme=&quot;@style/AppTheme&quot; &gt;

            &lt;activity
                android:name=&quot;.MainActivity&quot;
                android:label=&quot;@string/title_activity_main&quot; &gt;
                &lt;intent-filter&gt;
                    &lt;action android:name=&quot;android.intent.action.MAIN&quot; /&gt;

                    &lt;category android:name=&quot;android.intent.category.LAUNCHER&quot; /&gt;
                &lt;/intent-filter&gt;
            &lt;/activity&gt;

            &lt;meta-data
                android:name=&quot;com.google.android.maps.v2.API_KEY&quot;
                android:value=&quot;##myapikey##&quot;/&gt;

        &lt;/application&gt;
    &lt;/manifest&gt;

File MainActivity.java:

    public class MainActivity extends Activity {

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            getMenuInflater().inflate(R.menu.activity_main, menu);
            return true;
        }
    }

File activity_main.xml

    &lt;RelativeLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot; &gt;

        &lt;fragment xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
            android:id=&quot;@+id/map&quot;
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;match_parent&quot;
            class=&quot;com.google.android.gms.maps.MapFragment&quot;/&gt;
    &lt;/RelativeLayout&gt;

Clicking &quot;Update&quot; crashes the app with the following stacktrace:

    E/Trace(1034): error opening trace file: No such file or directory (2)
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    W/GooglePlayServicesUtil(1034): Google Play services out of date.  Requires 2010100 but found 1
    D/gralloc_goldfish(1034): Emulator without GPU emulation detected.
    D/AndroidRuntime(1034): Shutting down VM
    W/dalvikvm(1034): threadid=1: thread exiting with uncaught exception (group=0x40a13300)

    E/AndroidRuntime(1034): FATAL EXCEPTION: main
    E/AndroidRuntime(1034): android.content.ActivityNotFoundException: No Activity found to handle Intent
      { act=android.intent.action.VIEW dat=http://play.google.com/store/apps/details? \
      id=com.google.android.apps.bazaar flg=0x80000 pkg=com.android.vending }
    E/AndroidRuntime(1034):     at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1545)
    E/AndroidRuntime(1034):     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1416)
    E/AndroidRuntime(1034):     at android.app.Activity.startActivityForResult(Activity.java:3351)
    E/AndroidRuntime(1034):     at android.app.Activity.startActivityForResult(Activity.java:3312)
    E/AndroidRuntime(1034):     at android.app.Activity.startActivity(Activity.java:3522)
    E/AndroidRuntime(1034):     at android.app.Activity.startActivity(Activity.java:3490)
    E/AndroidRuntime(1034):     at com.google.android.gms.internal.c$2.onClick(Unknown Source)
    E/AndroidRuntime(1034):     at android.view.View.performClick(View.java:4084)
    E/AndroidRuntime(1034):     at android.view.View$PerformClick.run(View.java:16966)
    E/AndroidRuntime(1034):     at android.os.Handler.handleCallback(Handler.java:615)
    E/AndroidRuntime(1034):     at android.os.Handler.dispatchMessage(Handler.java:92)
    E/AndroidRuntime(1034):     at android.os.Looper.loop(Looper.java:137)
    E/AndroidRuntime(1034):     at android.app.ActivityThread.main(ActivityThread.java:4745)
    E/AndroidRuntime(1034):     at java.lang.reflect.Method.invokeNative(Native Method)
    E/AndroidRuntime(1034):     at java.lang.reflect.Method.invoke(Method.java:511)
    E/AndroidRuntime(1034):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
    E/AndroidRuntime(1034):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    E/AndroidRuntime(1034):     at dalvik.system.NativeStart.main(Native Method)

I&#39;ve also referenced the Google Play Services project. What am I doing wrong here?

**UPDATE**

The corresponding bug in Google issue tracker (https://issuetracker.google.com/issues/35822258) was solved some time ago.

Now you can use Google Maps Android API in emulator and create Virtual devices with Play services as described in this answer:

https://stackoverflow.com/a/46246782/5140781

  [1]: http://i.stack.imgur.com/l8aX7.png


This app won&#39;t run unless you update Google Play Services (via Bazaar)

In the new Google Maps API for Android, we can [add a marker][1], but there is no way to (easily) remove one.

My solution is to keep the markers in a map and redraw the map when I want to remove a marker, but it is not very efficient.

&lt;!-- language: lang-java --&gt;

    private final Map&lt;String, MarkerOptions&gt; mMarkers = new ConcurrentHashMap&lt;String, MarkerOptions&gt;();
    
    private void add(String name, LatLng ll) {
      final MarkerOptions marker = new MarkerOptions().position(ll).title(name);
      mMarkers.put(name, marker);
    
      runOnUiThread(new Runnable() {
        @Override
        public void run() {
          mMap.addMarker(marker);
        }
      });
    }
    
    private void remove(String name) {
      mMarkers.remove(name);
    
      runOnUiThread(new Runnable() {
        @Override
        public void run() {
          mMap.clear();
    
          for (MarkerOptions item : mMarkers.values()) {
            mMap.addMarker(item);
          }
        }
      });
    }


Does anyone have a better idea?


  [1]: https://developers.google.com/maps/documentation/android/marker#add_a_marker

Remove a marker from a GoogleMap

I&#39;m making use of the new [Android Google Maps API][1]. 

I create an activity which includes a MapFragment. In the activity `onResume` I set the markers into the GoogleMap object and then define a bounding box for the map which includes all of the markers.

This is using the following pseudo code:


    LatLngBounds.Builder builder = new LatLngBounds.Builder();
    while(data) {
       LatLng latlng = getPosition();
       builder.include(latlng);
    }
    CameraUpdate cameraUpdate = CameraUpdateFactory
       .newLatLngBounds(builder.build(), 10);
    map.moveCamera(cameraUpdate);

The call to `map.moveCamera()` causes my application to crash with the following stack:

    Caused by: java.lang.IllegalStateException: 
        Map size should not be 0. Most likely, layout has not yet 

        at maps.am.r.b(Unknown Source)
        at maps.y.q.a(Unknown Source)
        at maps.y.au.a(Unknown Source)
        at maps.y.ae.moveCamera(Unknown Source)
        at com.google.android.gms.maps.internal.IGoogleMapDelegate$Stub
            .onTransact(IGoogleMapDelegate.java:83)
        at android.os.Binder.transact(Binder.java:310)
        at com.google.android.gms.maps.internal.IGoogleMapDelegate$a$a
            .moveCamera(Unknown Source)
        at com.google.android.gms.maps.GoogleMap.moveCamera(Unknown Source)
        at ShowMapActivity.drawMapMarkers(ShowMapActivity.java:91)
        at ShowMapActivity.onResume(ShowMapActivity.java:58)
        at android.app.Instrumentation
            .callActivityOnResume(Instrumentation.java:1185)
        at android.app.Activity.performResume(Activity.java:5182)
        at android.app.ActivityThread
            .performResumeActivity(ActivityThread.java:2732)


If - instead of the `newLatLngBounds()` factory method I use `newLatLngZoom()` method then the same trap does not occur.

Is the `onResume` the best place to draw the markers onto the GoogleMap object or should I be drawing the markers and setting the camera position somewhere else?


  [1]: https://developers.google.com/maps/documentation/android/reference/com/google/android/gms/maps/package-summary

moveCamera with CameraUpdateFactory.newLatLngBounds crashes

My steps: 
 
* got SHA1 code from debug.keystore  
* create app in google apis console  
* enabled google map api v2  
* input SHA1;my.package.name  
* get API key  
* created AndroidManifest file:  
  

     &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
        &lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
                  package=&quot;my.package.name&quot;
                  android:versionCode=&quot;1&quot;
                  android:versionName=&quot;1.0&quot;&gt;
        
            &lt;permission
                    android:name=&quot;my.package.name.permission.MAPS_RECEIVE&quot;
                    android:protectionLevel=&quot;signature&quot;/&gt;
        
            &lt;uses-permission android:name=&quot;my.package.name.permission.MAPS_RECEIVE&quot;/&gt;
        
            &lt;uses-sdk android:minSdkVersion=&quot;8&quot; android:targetSdkVersion=&quot;15&quot;/&gt;
        
            &lt;uses-permission android:name=&quot;android.permission.INTERNET&quot;/&gt;
            &lt;uses-permission android:name=&quot;android.permission.WRITE_EXTERNAL_STORAGE&quot;/&gt;
            &lt;uses-permission android:name=&quot;android.permission.ACCESS_COARSE_LOCATION&quot;/&gt;
            &lt;uses-permission android:name=&quot;android.permission.ACCESS_FINE_LOCATION&quot;/&gt;
            &lt;uses-permission android:name=&quot;com.google.android.providers.gsf.permission.READ_GSERVICES&quot; /&gt;
        
            &lt;uses-feature android:glEsVersion=&quot;0x00020000&quot; android:required=&quot;true&quot;/&gt;
        
            &lt;application android:label=&quot;@string/app_name&quot; android:icon=&quot;@drawable/ic_launcher&quot; android:hardwareAccelerated=&quot;true&quot;&gt;
        
                &lt;meta-data android:name=&quot;com.google.android.maps.v2.API_KEY&quot; android:value=&quot;MY_API_KEY_HERE&quot; /&gt;
        
                &lt;activity android:name=&quot;MyActivity&quot;
                          android:label=&quot;@string/app_name&quot;&gt;
                    &lt;intent-filter&gt;
                        &lt;action android:name=&quot;android.intent.action.MAIN&quot;/&gt;
                        &lt;category android:name=&quot;android.intent.category.LAUNCHER&quot;/&gt;
                    &lt;/intent-filter&gt;
                &lt;/activity&gt;
            &lt;/application&gt;
        &lt;/manifest&gt;

* created layout  
* put &quot;google-play-services.jar&quot; to libs  

After compilation I&#39;ve got crash: 
   

      ERROR/AndroidRuntime(10182): FATAL EXCEPTION: main
                    java.lang.NoClassDefFoundError: com.google.android.gms.R$styleable
                    at com.google.android.gms.maps.GoogleMapOptions.createFromAttributes(Unknown Source)
                    at com.google.android.gms.maps.MapFragment.onInflate(Unknown Source)
                    at android.app.Activity.onCreateView(Activity.java:4716)
                    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
                    at android.view.LayoutInflater.inflate(LayoutInflater.java:466)
                    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
                    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
                    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
                    at android.app.Activity.setContentView(Activity.java:1881)
                    at com.example.gm2.MyActivity.onCreate(MyActivity.java:16)
                    at android.app.Activity.performCreate(Activity.java:5104)
                    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
                    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
                    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
                    at android.app.ActivityThread.access$600(ActivityThread.java:141)
                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
                    at android.os.Handler.dispatchMessage(Handler.java:99)
                    at android.os.Looper.loop(Looper.java:137)
                    at android.app.ActivityThread.main(ActivityThread.java:5039)
                    at java.lang.reflect.Method.invokeNative(Native Method)
                    at java.lang.reflect.Method.invoke(Method.java:511)
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
                    at dalvik.system.NativeStart.main(Native Method)

After that I&#39;ve changed layout to:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    
    &lt;FrameLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
                 android:id=&quot;@+id/map&quot;
                 android:layout_width=&quot;match_parent&quot;
                 android:layout_height=&quot;match_parent&quot; /&gt;

 and changed MyActivity to


  

      super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
                        
        FragmentManager manager = getFragmentManager();
        FragmentTransaction transaction = manager.beginTransaction();
                        
        transaction.add(R.id.map, MapFragment.newInstance());           
        transaction.commit();

As result, the application was started, but I didn&#39;t see the map. 

Console log:

    ERROR/Google Maps Android API(10369): Authorization failure.



Google Maps Android API v2 Authorization failure

I have one activity - `MainActivity`. Within this activity I have two fragments, both of which I created declaratively within the xml. 

I am trying to pass the `String` of text input by the user into `Fragment A` to the text view in `Fragment B`. However, this is proving to be very difficult. Does anyone know how I might achieve this?

I am aware that a fragment can get a reference to it&#39;s activity using `getActivity()`. So I&#39;m guessing I would start there?


Basic communication between two fragments

I have a REST service which I&#39;m calling from my app, which pulls in a JSON object as a `byte[]` that is then turned into a nice nested collection of objects -- all of that bit works fine. What I then want to do is persist these objects to SQLite storage using OrmLite, and that&#39;s where things start to break down, because as I understand, OrmLite doesn&#39;t automatically persist nested objects.

For simplicity, let&#39;s strip out my actual functionality and let my objects be modelled simply as followed:

    @DatabaseTable(tableName = &quot;parents&quot;)
    public class Parent {
    
    	@DatabaseField(id=true)
    	private String name;
    	
    	@ForeignCollectionField
        // have to use Collection here because needs to be compatible with Jackson
    	private Collection&lt;Child&gt; children; 
    	
    	/* Getters and setters go here */
    }
    
    @DatabaseTable(tableName = &quot;children&quot;)
    public class Child {
    
    	@DatabaseField(id=true)
    	private String name;
    	
    	@DatabaseField(foreign=true)
    	private Parent parent;
    
    	/* Getters and setters go here */
    }

What happens is that when adding creating a new `Parent` object in the database with my corresponding `parentDao` object, the children are not being persisted along with the parent.

This is a common question and has been raised before, there are definitely other questions on SO which are very similar to this one, most notably https://stackoverflow.com/questions/4745652/saving-nested-foreign-objects-with-ormlite-on-android in answer to which Gray suggests creating the child object before the parent which would work fine for creating my POJOs manually.

However, I&#39;ve not yet seen an answer which factors in cases where the objects are being generated by another library (in this case Jackson). Without digging deeper into Jackson&#39;s deserialisation innards (which removes the whole benefit of its simplicity) and trying to get Jackson to create the child objects and then add them to the parent (unless I&#39;m missing something and this is easier than it sounds?) that doesn&#39;t seem to be a particularly attractive solution in this particular case.

Equally, there are other solutions which involve adding further annotations to the foreign key which seem to be suitable for working with single child objects, but those annotations aren&#39;t available when working with `@ForeignCollectionField`s and their corresponding `Collection`s.

Content Type	Original Author	Original Content on Stackoverflow
Question	Ravi G	View Question on Stackoverflow
Solution 1 - Android	R World	View Answer on Stackoverflow
Solution 2 - Android	Philipp	View Answer on Stackoverflow
Solution 3 - Android	Tom	View Answer on Stackoverflow

Green DAO vs ORM lite vs Active Android

Android Problem Overview

Android Solutions

Solution 1 - Android

Solution 2 - Android

Solution 3 - Android

Specified platform toolset (v110) is not installed

Scala on iOS using Avian

Attributions