Sphero Android cannot instantiate SpheroConnectionView

Question

I'm trying to learn Sphero Android SDK and following the official tutorial . First I added RobotLibrary.jar to my project successfully, no compile errors. Next I put SpheroConnectionView to my layout file like this:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#ff888888" >

    <orbotix.view.connection.SpheroConnectionView
        android:id="@+id/sphero_connection_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#FFF" />

</LinearLayout>

Then I added the following code to MainActivity.java

public class MainActivity extends Activity {

    private SpheroConnectionView mSpheroConn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mSpheroConn=(SpheroConnectionView)findViewById(R.id.sphero_connection_view);

    }

}

I expect to see usual Sphero Connection View, (it's fairly simple code) but it throws an exception like this:

02-25 15:15:53.161: E/AndroidRuntime(1241): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ecem.spheroblank/com.ecem.spheroblank.MainActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class orbotix.view.connection.SpheroConnectionView

Here is the full stacktrace:

02-25 15:15:53.161: E/AndroidRuntime(1241): FATAL EXCEPTION: main
02-25 15:15:53.161: E/AndroidRuntime(1241): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ecem.spheroblank/com.ecem.spheroblank.MainActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class orbotix.view.connection.SpheroConnectionView
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.os.Looper.loop(Looper.java:137)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread.main(ActivityThread.java:4745)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at java.lang.reflect.Method.invokeNative(Native Method)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at java.lang.reflect.Method.invoke(Method.java:511)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at dalvik.system.NativeStart.main(Native Method)
02-25 15:15:53.161: E/AndroidRuntime(1241): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class orbotix.view.connection.SpheroConnectionView
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.createView(LayoutInflater.java:613)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:687)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.Activity.setContentView(Activity.java:1867)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at com.ecem.spheroblank.MainActivity.onCreate(MainActivity.java:20)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.Activity.performCreate(Activity.java:5008)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
02-25 15:15:53.161: E/AndroidRuntime(1241):     ... 11 more
02-25 15:15:53.161: E/AndroidRuntime(1241): Caused by: java.lang.reflect.InvocationTargetException
02-25 15:15:53.161: E/AndroidRuntime(1241):     at java.lang.reflect.Constructor.constructNative(Native Method)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at android.view.LayoutInflater.createView(LayoutInflater.java:587)
02-25 15:15:53.161: E/AndroidRuntime(1241):     ... 22 more
02-25 15:15:53.161: E/AndroidRuntime(1241): Caused by: java.lang.ExceptionInInitializerError
02-25 15:15:53.161: E/AndroidRuntime(1241):     at orbotix.view.connection.SpheroConnectionView.startDiscovery(SpheroConnectionView.java:236)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at orbotix.view.connection.SpheroConnectionView.<init>(SpheroConnectionView.java:215)
02-25 15:15:53.161: E/AndroidRuntime(1241):     ... 25 more
02-25 15:15:53.161: E/AndroidRuntime(1241): Caused by: java.lang.NullPointerException
02-25 15:15:53.161: E/AndroidRuntime(1241):     at orbotix.robot.base.RobotProvider.<init>(RobotProvider.java:161)
02-25 15:15:53.161: E/AndroidRuntime(1241):     at orbotix.robot.base.RobotProvider.<clinit>(RobotProvider.java:78)
02-25 15:15:53.161: E/AndroidRuntime(1241):     ... 27 more

So how can I fix it?

Answer 1

Finally, I found out the answer. I'm writing this down, so it may be helpful for other developers who interests in Sphero Android SDK.

Right click on the project > Select properties >> Open "Java Compiler" section. Make sure that you checked "Enable project specific settings" and set "Compiler compliance level" to 1.6!