How to refactor variable type in Eclipse?

Question

I want to refactor code like this:

int x=4;
int y=x;
System.out.println(y);

How can i do this automatically in Eclipse so x's type promotion to long would cause dependent variables to change their types also:

long x=4;
long y=x;
System.out.println(y);

?

Solution 1

How I usually do is that I change one of the upstream variables to long. This causes Eclipse to give error from each assignment where you offer long instead of int. Then I just select ctrl-1 (Quick-fix) on each of them and pick "change variable x to long".

This works when the new type is not directly assignable to the old one.

Solution 2

I don't think you can do this directly using the refactoring tool in Eclipse. However, what you can do is place your cursor over the variable x and hit CTRL + SHIFT + G to find all references in your workspace. This will then allow you to change any dependent references.

Solution 3

IntelliJ has this feature (refactor->type migration), but unfortunately, Eclipse doesn't have it yet. I hope Eclipse will add it soon.