Question

Can someone tell me why this simple code wont work? In the first activity I have the user choose an option which sends an arraylist to the next activity.
It will not do the else statement and force closes. Thanks guys!

String[] quotes;

ArrayList<String> Dark = new ArrayList<String>();
ArrayList<String> Light = new ArrayList<String>();

Heres the code

if (Dark.isEmpty()){

    Light = i.getStringArrayListExtra("light");
    quotes = Light.toArray(new String[Light.size()]);
} else {

    Dark = i.getStringArrayListExtra("dark");
    quotes = Dark.toArray(new String[Dark.size()]); 
};

here is how i send it

 public void dark (View d){
    dark.add("Even 0 is a number, just leave him alone!");
    dark.add("Love is noting but a bad spell, cast onto your soul, never to be released into the wild...");
    dark.add("The end is near please do not make the same mistakes.");
    dark.add( "Jenna i love you, youre my little beandip, dive you!");
    dark.add( "cute hate but dont rate im no skate");
    dark.add("You will never live if you live a lie");
    Intent intent = new Intent(choose.this,Startme.class);
    intent.putStringArrayListExtra("dark",dark);
    startActivity(intent);
 }

public void light (View l) {
    light.add("Good ideas will come if you share your love");
    light.add("enter a world with no doubt, join god");
    light.add("come on, can you live a life");
    light.add( "where love is so is hate lol not");
    light.add( "watch me now!! go with me and join the lord");
    light.add("never be afrade of the darkness");

    Intent intent = new Intent(choose.this,Startme.class);
    intent.putStringArrayListExtra("light",light);
    startActivity(intent);
}

Log

07-30 17:41:33.457: E/AndroidRuntime(15638): FATAL EXCEPTION: main
07-30 17:41:33.457: E/AndroidRuntime(15638): java.lang.RuntimeException: Unable to start activity ComponentInfo{me.me.quote/me.me.quote.Startme}: java.lang.NullPointerException
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1696)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1716)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread.access$1500(ActivityThread.java:124)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:968)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.os.Looper.loop(Looper.java:130)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread.main(ActivityThread.java:3806)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at java.lang.reflect.Method.invokeNative(Native Method)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at java.lang.reflect.Method.invoke(Method.java:507)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at dalvik.system.NativeStart.main(Native Method)
07-30 17:41:33.457: E/AndroidRuntime(15638): Caused by: java.lang.NullPointerException
07-30 17:41:33.457: E/AndroidRuntime(15638):    at me.me.quote.Startme.onCreate(Startme.java:164)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-30 17:41:33.457: E/AndroidRuntime(15638):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1660)
07-30 17:41:33.457: E/AndroidRuntime(15638):    ... 11 more

Here is the full code:

 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.startquotes);

    Intent i = getIntent(); 

    if (Dark.isEmpty()){

        Light = i.getStringArrayListExtra("light");
        quotes = Light.toArray(new String[Light.size()]);
    } else {

        Dark = i.getStringArrayListExtra("dark");
        quotes = Dark.toArray(new String[Dark.size()]); 
    }

    Button clouds = (Button) findViewById(R.id.Change);
    TranslateAnimation cloud2 = new TranslateAnimation(0, 0, +200, 0);
    clouds.startAnimation(cloud2);
    cloud2.setDuration(1000);

    Button clouds3 = (Button) findViewById(R.id.nxt);
    TranslateAnimation cloud3 = new TranslateAnimation(+200, 0, 0, 0);
    clouds3.startAnimation(cloud3);
    cloud3.setDuration(1000);

    Button clouds4 = (Button) findViewById(R.id.back);
    TranslateAnimation cloud4 = new TranslateAnimation(-200, 0, 0, 0);
    clouds4.startAnimation(cloud4);
    cloud4.setDuration(1000);

    AdView adview = (AdView)findViewById(R.id.adView);
    AdRequest re = new AdRequest();
    re.setTesting(true);
    adview.loadAd(re);

    String ser = SerializeObject.ReadSettings(Startme.this, "myobject.dat");
    if (ser != null && !ser.equalsIgnoreCase("")) {
        Object obj = SerializeObject.stringToObject(ser);
        // Then cast it to your object and 
        if (obj instanceof ArrayList) {
            // Do something
            give = (ArrayList<String>)obj;
        }
    }

    TextView Dark=(TextView)findViewById(R.id.Quote); 

    Typeface face=Typeface.createFromAsset(getAssets(), "fonts/font1.ttf"); 
    Dark.setTypeface(face); 

    num = gen.nextInt(5);
    TextView text = (TextView) findViewById(R.id.Quote);
    text.setText( quotes[num]);

    TextView number = (TextView) findViewById(R.id.Qn);
    number.setText("#"+num);

    TextView Q=(TextView)findViewById(R.id.Qn); 
    Typeface tf=Typeface.createFromAsset(getAssets(), "fonts/titlefont.ttf"); 
    Q.setTypeface(tf); 

    }
}

line 164

    if (Dark.isEmpty()){

        Light = i.getStringArrayListExtra("light");
----------> quotes = Light.toArray(new String[Light.size()]);
    } else {

Answer 1

It will never do your else statement because your Dark arraylist will always be empty. You initialize it like that in your activity and you never read it from your intent. You might want to read both first and decide executing if or else depending on the “null”ity of one. You will see why below.

The getStringArrayListExtra(key) function will return null by default if the key you give to it does not exist, which means there was never an extra with key “light” added to your intent. This suggests that your light() function is not getting called.

I would suggest checking your class that includes light() and dark().