java用捕获组替换所有

Question

如果字符串的格式如下，我想在字符串中插入空格：

(A)   => (A)
(A)B  => (A) B
A(B)  => A (B)
A(B)C => A (B) C
AB(C) => AB (C)

提前谢谢你

编辑：仅当有匹配的括号时，才应进行替换

AB(C => AB(C should remain as is.