Unable to instantiate activity ComponentInfo... java.lang.NullPointerException
android, android-activity
Solution
We don't have any code to confirm, but the error seems to suggest that you are trying to use `getString` from within `NovaAtividadeActivity`'s constructor. An `Activity` is not created until the `onCreate` call, so you would have to move your code from the constructor to that function.
Update: Now that you added the code for the activity, we can see that you are calling `getString` to initialize the member `DIAS`, which will happen at the class' constructor. Instead, move the initialization of `DIAS` to `onCreate`.
Problem
I'm having the error "Unable to instantiate activity ComponentInfo" in my app. I had already declared the Activity in AndroidManifest.xml, but I still get the error. I don't know what it is. Does anyone can help? thanks The error: ``` FATAL EXCEPTION: main java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{br.com.controladoratividades/br.com.controladoratividades.activities.NovaAtividadeActivity}: java.lang.NullPointerException at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) at android.app.ActivityThread.access$2300(ActivityThread.java:125) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:123) at android.app.ActivityThread.main(ActivityThread.java:4627) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:521) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.NullPointerException at android.content.ContextWrapper.getResources(ContextWrapper.java:80) at android.content.Context.getString(Context.java:182) at br.com.controladoratividades.activities.NovaAtividadeActivity.<init>(NovaAtividadeActivity.java:15) at java.lang.Class.newInstanceImpl(Native Method) at java.lang.Class.newInstance(Class.java:1429) at android.app.Instrumentation.newActivity(Instrumentation.java:1021) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) ... 11 more ``` My AndroidManifest.xml: ``` <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="br.com.controladoratividades" android:versionCode="1" android:versionName="1.0" > <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".activities.ControladorAtividadesActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".activities.NovaAtividadeActivity" android:label="@string/nova_atividade" > </activity> <activity android:name=".activities.PlanejadorActivity" android:label="@string/novo_plano" > </activity> </application> <uses-sdk android:minSdkVersion="7" /> </manifest> ``` The activity: ``` package br.com.controladoratividades.activities; import br.com.controladoratividades.R; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.content.DialogInterface; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; public class NovaAtividadeActivity extends Activity { private String[] DIAS = new String[] {getString(R.string.domingo), getString(R.string.segunda), getString(R.string.terca), getString(R.string.quarta), getString(R.string.quinta), getString(R.string.sexta), getString(R.string.sabado)}; protected boolean[] DIAS_SELECIONADOS = new boolean[ DIAS.length ]; static final int DIAS_DIALOG_ID = 0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.nova_atividade); Button btAlterarDias = (Button)findViewById(R.id.btSalvarPlano); btAlterarDias.setOnClickListener(new AlterarDiasClickHandler()); for (int i = 1; i < DIAS_SELECIONADOS.length; i++) { DIAS_SELECIONADOS[i] = true; } } public class AlterarDiasClickHandler implements View.OnClickListener{ @Override public void onClick(View v) { showDialog(DIAS_DIALOG_ID); } } @Override protected Dialog onCreateDialog( int id ) { return new AlertDialog.Builder( this ) .setTitle( "Planets" ) .setMultiChoiceItems( DIAS, DIAS_SELECIONADOS, new DialogSelectionClickHandler() ) .setPositiveButton( "OK", new DialogButtonClickHandler() ) .create(); } public class DialogSelectionClickHandler implements DialogInterface.OnMultiChoiceClickListener { public void onClick( DialogInterface dialog, int clicked, boolean selected ) { Log.i( "ME", DIAS[ clicked ] + " selected: " + selected ); } } public class DialogButtonClickHandler implements DialogInterface.OnClickListener { public void onClick( DialogInterface dialog, int clicked ) { switch( clicked ) { case DialogInterface.BUTTON_POSITIVE: //printSelectedPlanets(); break; } } } } ```