CODEWITHSUNDEEP
javaandroidxmlgradle
MCoder
MCoder

Reputation: 83

Android Studio: FATAL EXCEPTION

I am trying to create an app. When testing it, whenever I try to press a button, the app on the phone says, "Unfortunately, [application name] has stopped."

On logcat, a message appears:

E/AndroidRuntime: FATAL EXCEPTION: main
 Process: com.example.inspiron.firstapplication, PID: 6746
 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.inspiron.firstapplication/com.example.inspiron.firstapplication.Text}: java.lang.NullPointerException
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2321)
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2507)
     at android.app.ActivityThread.access$900(ActivityThread.java:172)
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
     at android.os.Handler.dispatchMessage(Handler.java:102)
     at android.os.Looper.loop(Looper.java:146)
     at android.app.ActivityThread.main(ActivityThread.java:5692)
     at java.lang.reflect.Method.invokeNative(Native Method)
     at java.lang.reflect.Method.invoke(Method.java:515)
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
     at dalvik.system.NativeStart.main(Native Method)
  Caused by: java.lang.NullPointerException
     at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:68)
     at android.support.v7.app.AppCompatDelegateImplV7.<init>(AppCompatDelegateImplV7.java:146)
     at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:28)
     at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:41)
     at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:190)
     at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:172)
     at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:512)
     at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:184)
     at com.example.inspiron.firstapplication.Text.<init>(Text.java:17)
     at java.lang.Class.newInstanceImpl(Native Method)
     at java.lang.Class.newInstance(Class.java:1208)
     at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2312)
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2507) 
     at android.app.ActivityThread.access$900(ActivityThread.java:172) 
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308) 
     at android.os.Handler.dispatchMessage(Handler.java:102) 
     at android.os.Looper.loop(Looper.java:146) 
     at android.app.ActivityThread.main(ActivityThread.java:5692) 
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:515) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107) 
     at dalvik.system.NativeStart.main(Native Method) 

My XML looks like this: 

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="English:"
    android:id="@+id/LanguageTranslatedFrom"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:textSize="20dp" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/TextBar"
    android:layout_below="@+id/LanguageTranslatedFrom"
    android:layout_toEndOf="@+id/LanguageTranslatedFrom"
    android:hint="PUT IN what you want to translate..." />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Spanish:"
    android:id="@+id/LanguageTranslatedTo"
    android:layout_centerVertical="true"
    android:layout_alignParentStart="true"
    android:textSize="20dp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="OK"
    android:id="@+id/ConfirmationButton"
    android:layout_below="@+id/TextBar"
    android:layout_alignParentEnd="true"
    android:background="#61ff00" />

<ImageButton
    android:layout_width="50dp"
    android:layout_height="100dp"
    android:id="@+id/TextIcon"
    android:src="@drawable/keyboard"
    android:layout_centerVertical="true"
    android:layout_toEndOf="@+id/LanguageTranslatedTo"
    android:layout_alignParentEnd="true" />

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/ViaVoiceButton"
    android:layout_below="@+id/LanguageTranslatedTo"
    android:layout_alignParentStart="true"
    android:src="@drawable/microphone"
    android:layout_toStartOf="@+id/Result" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="What the output is..."
    android:id="@+id/Result"
    android:layout_below="@+id/TextIcon"
    android:layout_toEndOf="@+id/LanguageTranslatedTo"
    android:textSize="18dp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Retry"
    android:id="@+id/Retryit"
    android:layout_below="@+id/ConfirmationButton"
    android:layout_alignParentEnd="true"
    android:background="#61ff00" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="BACK"
    android:id="@+id/button"
    android:layout_alignParentBottom="true"
    android:layout_toStartOf="@+id/Result"
    android:background="#ff0000" />

<Spinner
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/LanguagePicker"
    android:layout_above="@+id/TextBar"
    android:layout_toEndOf="@+id/Result" />

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/LanguageTranslatedTo"
    android:layout_centerHorizontal="true">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/textView2"
        android:layout_gravity="left|top" />
</FrameLayout>

Finally, my java looks like this:

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.LayoutInflater;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class Text extends AppCompatActivity {
    final Context context = this;
    Button button = (Button) findViewById(R.id.ConfirmationButton);


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.text_wall);
    Spinner spinner = (Spinner) findViewById(R.id.LanguagePicker);



    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            R.array.language, android.R.layout.simple_spinner_item);

    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner.setAdapter(adapter);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            LayoutInflater li = LayoutInflater.from(context);
            View promptsView = li.inflate(R.layout.alertdialog, null);

            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                    context);


            alertDialogBuilder.setView(promptsView);
            alertDialogBuilder
                    .setCancelable(false)
                    .setPositiveButton("OK",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,int id) {

                                    Spinner spinner = (Spinner) findViewById(R.id.LanguagePicker);
                                    String text = spinner.getSelectedItem().toString();
                                }
                            })
                    .setNegativeButton("Cancel",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    dialog.cancel();
                                }
                            });
            AlertDialog alertDialog = alertDialogBuilder.create();
            alertDialog.show();
        }
    });
}

}

Upvotes: 0

Views: 1032

Answers (1)

Pier Giorgio Misley
Pier Giorgio Misley

Reputation: 5351

Move the button initialization in the onCreate method. You can't do it before this method because the view is not rendered and the items are not ready. Change the Java code like the following:

import android.view.LayoutInflater;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class Text extends AppCompatActivity {
    Context context;
    Button button;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.text_wall);
    Spinner spinner = (Spinner) findViewById(R.id.LanguagePicker);
    button = (Button) findViewById(R.id.ConfirmationButton);
    context = this; // why this? why using context when you have this?


    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            R.array.language, android.R.layout.simple_spinner_item);

    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner.setAdapter(adapter);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            LayoutInflater li = LayoutInflater.from(context);
            View promptsView = li.inflate(R.layout.alertdialog, null);

            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                    context);


            alertDialogBuilder.setView(promptsView);
            alertDialogBuilder
                    .setCancelable(false)
                    .setPositiveButton("OK",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,int id) {

                                    Spinner spinner = (Spinner) findViewById(R.id.LanguagePicker);
                                    String text = spinner.getSelectedItem().toString();
                                }
                            })
                    .setNegativeButton("Cancel",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    dialog.cancel();
                                }
                            });
            AlertDialog alertDialog = alertDialogBuilder.create();
            alertDialog.show();
        }
    });
}

}

In addiction check if your activity is present in the manifest; if not, post the full manifest please.

Upvotes: 3

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