Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to com.xxx

Question

After browsing multiple questions regarding that and trying multiple things, I end up with the current error. Basically, I am trying to dynamically fill a list view by clicking a button.

For that, I have the following .xml extract:

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/new_exercise_button"
        android:id="@+id/exercise_add"
        android:onClick="addItems"             />
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:drawSelectorOnTop="false" />

I implemented a class RoutineListView for handling the list:

public class RoutineListView extends ListActivity {
    ArrayList<String> listItems=new ArrayList<String>();
    ArrayAdapter<String> adapter;

    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.fragment_main);
        adapter=new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                listItems);
        setListAdapter(adapter);
    }
    public void addLItems(View v) {
        adapter.add("hi");
    }
}

And when the button in my main activity is clicked, I try to invoke the method with the following code in my MainActivity:

public void addItems(View v){
    RoutineListView routineListView = (RoutineListView)this.getApplicationContext();
    routineListView.addLItems(v);
}

However, debugger throws me the following error for the getApplicationContext() - if I don't implement it, I get a null exception for adapter.add().

Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to com.mycompany.ownfitnesstracker.RoutineListView

And last, but not least, I registered my RoutineListView in the manifest:

    <activity
        android:name=".RoutineListView"
        android:label="@string/routine_list_name" >
        <intent-filter>
            <action android:name="android.intent.action.GET_CONTENT" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>

Can you please show your code from the MainActivity?

Thomaz Freitas Barbosa
– Thomaz Freitas Barbosa

2015-08-11 15:27:09 +00:00
Commented Aug 11, 2015 at 15:27 — Thomaz Freitas Barbosa
– Thomaz Freitas Barbosa, Commented Aug 11, 2015 at 15:27
and the stack trace of the error

Zoltán
– Zoltán

2015-08-11 15:34:30 +00:00
Commented Aug 11, 2015 at 15:34 — Zoltán
– Zoltán, Commented Aug 11, 2015 at 15:34

Karakuri · Accepted Answer · 2015-08-11 15:41:23Z

1

RoutineListView is an Activity, not an Application. getApplicationContext() does not return an Activity. You can't obtain a reference to a RoutineListView this way.

There are certain ways to communicate between activities, but rarely does that involve direct method invocations from one to another. Most of the time you use Intents, or you store data outside the activities (e.g. with SharedPreferences).

answered Aug 11, 2015 at 15:41

Karakuri

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Comments

mihirjoshi · Accepted Answer · 2015-08-11 15:42:14Z

0

You can directly call addItems without using an object.

public void addItems(View v){
    addLItems(v);
}

answered Aug 11, 2015 at 15:42

mihirjoshi

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