java.lang.InstantiationException: can't instantiate class : no empty constructor

Question

I'm trying to create a game on Android and I have a problem with the instanciation of the view. I'm using an inflated view.

Here is my code for the view :

public class GameView extends TableLayout {

public GameView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

for the activity

public class GameActivity extends Activity {

private GameView view;

@Override
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    this.view = (GameView) View.inflate(this,R.layout.game, null);
}

and here is the error

D/dalvikvm( 6176): newInstance failed: no <init>()
D/AndroidRuntime( 6176): Shutting down VM
W/dalvikvm( 6176): threadid=1: thread exiting with uncaught exception (group=0x41a80700)
E/AndroidRuntime( 6176): FATAL EXCEPTION: main
E/AndroidRuntime( 6176): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.android.homework.em.go/com.android.homework.em.go.GameView}: java.lang.InstantiationException: can't instantiate class com.android.homework.em.go.GameView; no empty constructor
E/AndroidRuntime( 6176):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
E/AndroidRuntime( 6176):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
E/AndroidRuntime( 6176):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
E/AndroidRuntime( 6176):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
E/AndroidRuntime( 6176):    at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 6176):    at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime( 6176):    at android.app.ActivityThread.main(ActivityThread.java:5103)
E/AndroidRuntime( 6176):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 6176):    at java.lang.reflect.Method.invoke(Method.java:525)
E/AndroidRuntime( 6176):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
E/AndroidRuntime( 6176):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
E/AndroidRuntime( 6176):    at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 6176): Caused by: java.lang.InstantiationException: can't instantiate class com.android.homework.em.go.GameView; no empty constructor
E/AndroidRuntime( 6176):    at java.lang.Class.newInstanceImpl(Native Method)
E/AndroidRuntime( 6176):    at java.lang.Class.newInstance(Class.java:1130)
E/AndroidRuntime( 6176):    at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
E/AndroidRuntime( 6176):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
E/AndroidRuntime( 6176):    ... 11 more
W/ActivityManager(  436):   Force finishing activity com.android.homework.em.go/.GameView

Thanks for your help !

EDIT :

1) The problem is that when I create an empty constructor, I can't compile because it says that the constructor is not compatible with the constructor of TableLayout.

2) I'm using View.inflate because I found it on this tutoriel : http://www.therealjoshua.com/2012/07/android-architecture-part-10-the-activity-revisited/ What I want is to set a view to my activity which is partly describe by an xml file (layout.game) and partly created programmaticaly with the class GameView.java How can I do that ?

Answer 1

In fact the problem was because I wasn't calling the correct activity in the manifest file. I called GameView instead of GameActivity.

Answer 2

I was trying to start an activity with an abstract class.

Answer 3

You could add an empty constructor:

public GameView() {
    super();
}

but are you sure that you don't mean to be doing something more like:

setContentView(R.layout.game);
this.view = (GameView) findViewById(R.id.gameView);

Inflating the view manually in an activity's creation seems a bit odd.

Answer 4

Try this

@Override
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.game);
    this.view = (GameView) findViewById(R.id.gameView);
}

You have to find id for your view on the layout

in your class make sure you have

public GameView(Context context) {
    super(context);
}

public GameView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public GameView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    if (widthMeasureSpec > 3000)
        widthMeasureSpec = widthMeasureSpec & 0xfff;
    if (heightMeasureSpec > 3000)
        heightMeasureSpec = heightMeasureSpec & 0xfff;
    setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
}