java.lang.NullPointerException: Attempt to read from null array

Question

I'm having problems with a simple custom list. I have tried a few examples and end up getting the same error. The error I keep getting is

java.lang.NullPointerException: Attempt to read from null array

Adapter Class:

public class CustomList  extends ArrayAdapter<String>   {

        Context context;
        int [] images;
        String [] titleArray;
        String [] descriptionArray;

        CustomList(Context context,String[] titles, int [] images, String [] description) {
            super(context,R.layout.single_row,R.id.textView,titles);
            this.context = context;
            this.images = images;
            this.descriptionArray = description;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View row =  inflater.inflate(R.layout.single_row,parent, false);

            ImageView img = (ImageView) row.findViewById(R.id.imageView);
            TextView myTxtTitle = (TextView) row.findViewById(R.id.textView);
            TextView myTxtDescription =  (TextView) row.findViewById(R.id.textView2);

            img.setImageResource(images[position]);
            myTxtTitle.setText(titleArray[position]); // where error is happening?
            myTxtDescription.setText(descriptionArray[position]);

            return row;
        }}

Activity class:

public class MainActivity extends AppCompatActivity {

    ListView list;
    String [] name;
    String [] sound;
    int [] images = {
            R.drawable.bird,
            R.drawable.cat,
            R.drawable.cow,
            R.drawable.dog,
            R.drawable.frog
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Resources res = getResources();
        name = res.getStringArray(R.array.title);
        sound = res.getStringArray(R.array.description);

        list = (ListView) findViewById(R.id.list);

        CustomList customAdapter = new CustomList(this, name, images, sound);
        list.setAdapter(customAdapter);
    }
}

ΦXocę 웃 Пepeúpa ツ · Accepted Answer · 2016-04-30 10:30:14Z

6

You just forgot to assign the title array... hence the array is null referenced....

String [] titleArray;
String [] descriptionArray;

CustomList(Context context,String[] titles, int [] images, String [] description)
    {
    super(context,R.layout.single_row,R.id.textView,titles);
    this.context = context;
    this.images = images;
    this.descriptionArray = description;


     //addd this to init the array
     this.titleArray = titles;
    }

answered Apr 30, 2016 at 10:30

ΦXocę 웃 Пepeúpa ツ

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Comments

Jihong Park · Accepted Answer · 2016-04-30 10:31:29Z

0

you need null check.

ex) if(titleArray != null) and if(descriptionArray != null)

It happens when you try to use the data that is null.

answered Apr 30, 2016 at 10:31

Jihong Park

11 bronze badge

1 Comment

Chris Sherlock Over a year ago

This check is not necessary, these Object == null check often indicates bad code in my opinion. Sure you need it sometimes, but not in this case, since you only need to initialize the array and it will no be null in any case

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