This is how I solved it,
ArrayList<customtype> dir = new ArrayList<customtype>();
ArrayList<String> listing = new ArrayList<String>();
customtype item;
for(int i=0;i<dir.size();i++)
{
item = dir.get(i);
listing.add(item.getPath());
//getPath is a method in the customtype class which will return value in string format
}
final CharSequence[] fol_list = listing.toArray(new CharSequence[listing.size()]);
//fol_list will have all the strings from getPath();