正则表达式 - 通过StringToWordVector过滤器删除阿拉伯文本中的重复字母

I want to remove repeated Arabic letters in my text. How can I do this using regex in Java? I've tried different regex but it removes all the Arabic letters from my text! help plz. BTW, I am using regex with StringToWordVector filter like what happening in I want to remove repeated Arabic letters in my