getFilter()' on a null object reference - nullpointerexception

Question

i'm trying to implement search on my list view
this is my custom adapter:
public class AllContactsAdapter extends BaseAdapter implements Filterable {
Context context;
ArrayList<Contact> contactList;
ArrayList<Contact> mStringFilterList;
ValueFilter valueFilter;
public AllContactsAdapter(Context context, ArrayList<Contact> list) {
this.context = context;
contactList = list;
mStringFilterList = list;
}
#Override
public int getCount() {
return contactList.size();
}
#Override
public Object getItem(int position) {
return contactList.get(position);
}
#Override
public long getItemId(int position) {
return contactList.get(position).getID();
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
Contact item = contactList.get(position);
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.row_name_phone_view, null);
}
TextView name = (TextView) convertView.findViewById(R.id.txtAllFullName);
name.setText(item.getName());
TextView phone = (TextView) convertView.findViewById(R.id.txtAllPhoneNumber);
phone.setText(item.getPhoneNumber());
return convertView;
}
#Override
public Filter getFilter() {
if (valueFilter == null) {
valueFilter = new ValueFilter();
}
return valueFilter;
}
private class ValueFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
if (constraint != null && constraint.length() > 0) {
ArrayList<Contact> filterList = new ArrayList<Contact>();
for (int i = 0; i < mStringFilterList.size(); i++) {
if ((mStringFilterList.get(i).getName().toUpperCase())
.contains(constraint.toString().toUpperCase())) {
Contact contact = new Contact(mStringFilterList.get(i)
.getName(), mStringFilterList.get(i)
.getPhoneNumber());
filterList.add(contact);
}
}
results.count = filterList.size();
results.values = filterList;
} else {
results.count = mStringFilterList.size();
results.values = mStringFilterList;
}
return results;
}
#Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
contactList = (ArrayList<Contact>) results.values;
notifyDataSetChanged();
}
}
}
this is my call in main activity:
#Override
public boolean onQueryTextChange(String newText) {
adapter.getFilter().filter(newText);
return false;
}
i'm getting this error:
java.lang.NullPointerException: Attempt to invoke virtual method 'android.widget.Filter com.example.shaka.contactsmanager.AllContactsAdapter.getFilter()' on a null object reference
can you please help me?

Answer 1

The variable adapter is null and you're trying to call the method getFilter() on it.
You need to initialize the adapter variable before using it. I can't be sure of how to do it because I can't see the MainActivity code, but it's definetely this problem.