Android ArrayAdapter update

I have this ArrayAdapter and i want to update the list items to show new items but my problem is that i don’t know how to clean the first list i create in app and the adapter then how to create a new one

public final class CustomList1 extends ArrayAdapter<String> {

    ImageView image;
    private String[] photos;
    private String[] urls=null;
    private Activity context=null;
    private String[] post=null;
    private String[] title=null;
    private String[] username=null;
    private String[] category=null;
    private String[] id=null;
    Bitmap mIcon11 = null;
    public View listViewItem=null ;

    public CustomList1(Activity context, String[] photos, String[] urls, String[] post, String[] title, String[] username, String[] id, String[] category) {
        super(context, R.layout.image_list_view1, photos);


        this.context = context;
        this.photos = photos;
        this.urls = urls;
        this.post = post;
        this.title = title;
        this.username = username;
        this.category = category;
        this.id = id;


    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = context.getLayoutInflater();
        listViewItem = inflater.inflate(R.layout.image_list_view1, null, true);
        TextView textViewURL = (TextView) listViewItem.findViewById(R.id.textViewURL);
        TextView textViewTITLE = (TextView) listViewItem.findViewById(R.id.textViewTITLE);
        TextView textViewUSERNAME = (TextView) listViewItem.findViewById(R.id.textViewUSERNAME);
        TextView textViewID = (TextView) listViewItem.findViewById(R.id.textViewID);
        TextView textViewCategory = (TextView) listViewItem.findViewById(R.id.textViewCategory);
        image = (ImageView) listViewItem.findViewById(R.id.imageDownloaded);

        textViewURL.setText(post[position]);
        textViewTITLE.setText(title[position]);
        textViewUSERNAME.setText(username[position]);
        textViewCategory.setText(category[position]);
        textViewID.setText(id[position]);
        Picasso.with(context).load(urls[position]).resize(200, 200).into(image);


        return listViewItem;

    }

}