Search Arabic custom listview

Question

I have a custom listview which has Arabic strings.I want to search for a specific view (row) in that listview .I use addTextChangedListener in my main activity like below

 editsearch = (EditText) findViewById(R.id.search);
        editsearch.addTextChangedListener(new TextWatcher() {

            @Override
            public void afterTextChanged(Editable arg0) {
                // TODO Auto-generated method stub
                String text = editsearch.getText().toString().toLowerCase(Locale.ENGLISH.getDefault());
                //String text = editsearch.getText().toString();
                adapter.filter(text);
            }

           @Override
            public void beforeTextChanged(CharSequence arg0, int arg1,int arg2, int arg3) {
                // TODO Auto-generated method stub
            }

            @Override
            public void onTextChanged(CharSequence arg0, int arg1, int arg2,int arg3) {
                // TODO Auto-generated method stub
            }
        });

In my adpater ,I use base adapter

   Context mContext;
    LayoutInflater inflater;
    private List<MyDataModelads2> modelList = null;
    private ArrayList<MyDataModelads2> arraylist;



    public myarraynew(Context context, List<MyDataModelads2> modelList) {
        mContext = context;
        this.modelList = modelList;
        inflater = LayoutInflater.from(mContext);
        this.arraylist = new ArrayList<MyDataModelads2>();
        this.arraylist.addAll(modelList);

    }

and I inserted the following filter method in my adapter

 public void filter(String charText) {
        charText = charText.toLowerCase(Locale.getDefault());
        modelList.clear();
        if (charText.length() == 0) {
            modelList.addAll(arraylist);
        } else {
            for (MyDataModelads2 wp : arraylist) {
                if (wp.getName().toLowerCase(Locale.getDefault()).contains(charText)) {
                    modelList.add(wp);
                }
            }
        }
        notifyDataSetChanged();
    }

There's two problems:

1. When I type a text in search bar , The list becomes empty even if I remove the text I typed (empty search bar).In other words, the list turns empty after I type any text in search bar and after I remove that text.
2. What should I add to my code to enable searching for Arabic language ? as I think the code is for English only