I am in a situation where I want to use mutable versions of things like Integer. Do I have to use these classes (below) or does Java have something built in?
http://www.java2s.com/Code/Java/Data-Type/Amutableintwrapper.htm
No, Java doesn't have these built in. And that is for a reason. Using mutable types is dangerous, as they can easily be misused. Additionally, it is really easy to implement it. For example, commons-lang has a MutableInt
.