How to convert a char array back to a string?
No, that solution is absolutely correct and very minimal.
Note however, that this is a very unusual situation: Because String is handled specially in Java, even "foo" is actually a String. So the need for splitting a String into individual chars and join them back is not required in normal code.
Compare this to C/C++ where "foo" you have a bundle of chars terminated by a zero byte on one side and string on the other side and many conversions between them due do legacy methods.