Tool for validating generics in Java <1.5

Question

Is there a tool that would allow me to check use of generic collections in code that must be compilable with Java 1.4? I would imagine example code as:

Map/*<String, Integer>*/ map = new HashMap();
map.put("abc", new Integer(3));  // ok
map.put("def", "ghi");  // warning

EDIT: Unfortunately the build process is "set in stone" to use Java 1.4, so the code I commit cannot contain any 1.5 features, or depend on any translation tools. The easiest solution so far seems to be maintaining local version of code for 1.5, and converting it to 1.4 before commit.

Answer 1

I'd recommend coding for 1.5 and using a tool like declawer (google for it, there are various updates to the original version floating around) to strip off the generics when you need to build 1.4 compatible code.

Works for us (although we added some features to the original declawer so that it could parse our source files).

Answer 2

Use -source 1.4 as a flag to the javac command. Here are the details.

Answer 3

Is the requirement really to compileable against 1.4, or only that it can run on 1.4? In the latter case, you can use Retroweaver. Or, if you only want to use generics, just compile with the undocumented -target jsr14 option.

But I'm pretty sure there isn't anything like you describe - what would be the point?

Answer 4

I'm not sure if I get this right: You want to write that comment "<String, Integer>" in your code and run some Static code analysis tool to check if it would compile?

I don't think there is such a thing right now but you should check out findbugs. Findbugs will help you with generics and stuff like this:

List<String> list = new ArrayList<String>();
list.add("foo");
list.contains(new Integer(5));

This is compilable code, because contains is not generic for compatibility reasons. However, findbugs gives you a nice warning for that.

Maybe you could write a findbugs detector yourself, that does what you need, but since finbugs works on byte code, you would need to use something different then comments e.g. annotations.