Crystal Ball - End of Stage 1 ERROR

Seems to be a NullPointer exception, which according to the Java Docs is:

Thrown when an application attempts to use null in a case where an object is required. These include: Calling the instance method of a null object. Accessing or modifying the field of a null object. Taking the length of null as if it were an array. Accessing or modifying the slots of null as if it were an array. Throwing null as if it were a Throwable value.

The lines 'Caused by: java.lang.NullPointerException 06-02 21:53:00.913: E/AndroidRuntime(1262): at com.example.crystalballx.MainActivity.onCreate(MainActivity.java:21)' provide a clue as to where the problem originates.

Could you post the content of your MainActivity file? Don't forget to use the Markdown formatting so it's easier to read :)

Hi Nick,

Thanks for your response! Here is my MainActivity.java file I'm hoping the Markdown formatting works!!

package com.example.crystalballx;

import java.util.Random;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

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

        final TextView answerLabel = (TextView) findViewById(R.id.textView1);
        Button getAnswerButton = (Button) findViewById(R.id.button1);

        getAnswerButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                String answer = "";

                Random RandomGeno = new Random();
                int randomNum = RandomGeno.nextInt(3);
                answer = Integer.toString(randomNum);

                answerLabel.setText(answer);
            }
        });

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

Hmm, nothing strikes me as fundamentally wrong with your code - the only exception is that you've capitalised a variable declaration (RandomGeno should be randomGeno). I don't think that would cause a NullPointerException... But it's worth changing regardless.

Nick, Thank you very much for your response. However changing it to randomGeno still didn't work. Any other ideas? Really want to get this working!

Well... This made me think this may be the issue. My textView1 and button1 are in my fragment_main.xml and nothing is in my activity_main.xml

I have posted both below, hopefully you could lead me to the exact issue / what to move where.

(Also quick side question - I seem to notice a trend, should everything within Eclipse/Java always start with a lower case and then every other word thats apart of the string be uppercase? For example you pointed our that instead of "RandomGeno" it should be "randomGeno"?)

Below is the Activity_Main.xml

``xml <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.crystalballx.MainActivity" tools:ignore="MergeRootFrame" />

Below is the fragment_main.xml
``xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.crystalballx.MainActivity$PlaceholderFragment" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="32sp" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_centerHorizontal="true"
        android:text="Enlighten Me!" />

</RelativeLayout>
``

Any ideas how to post XML so it shows all text?

Have repasted below not in markdown due to rendering issues:

Activity_main XML below:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.crystalballx.MainActivity" tools:ignore="MergeRootFrame" />

Fragment_main XML below:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.crystalballx.MainActivity$PlaceholderFragment" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:textSize="32sp" />

<Button
    android:id="@+id/button1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView1"
    android:layout_centerHorizontal="true"
    android:text="Enlighten Me!" />

</RelativeLayout>