在Ear Project Structure Eclipse下的两个Java Dynamic Web项目之间共享src文件夹

Question

i just wanted to clarify and know , how we can share codebase between project under Ear Project , following is my project layout

I Have one EAR Project, which has two appengine dynamic web application project added to it, as app1 and app2

i have all of my model java class and service class in app1 , and now i dont wanted to rewrite or have duplicate of these files in app2 , i just wanted to use these classes in app1 from app2.

Note : am not using maven, since there is a lot of issue with (maven + appengine + eclipse) and i dont want to complicate things.

In short, two web application project with shared src folder or part of it, is it possbile?

Any help is highly appreciated, Thanks!

Answer 1

You can't share code between two war files and you shouldn't.

You'll have to move shared code to a jar project, that is the correct way.

If you don't have maven, you can have an ant file doing that

Answer 2

In my opinion, yes it is possible and it most often makes sense to outsource libraries in own projects to share them.

Relevant places for including resources in Java (EE) projects are:

1. the Java build path
2. the linked resources list in Eclipse
3. the referenced libraries setting in Eclipse
4. The entries in files like application.xml, web.xml or other servlet container specific files.

Further, you can make usage of file system links to folders or source files.

Which one is useful and visible in the Eclipse project settings depends on the project type, the Eclipse version and plugin and the servlet container. Some entries in xml files are managed by Eclipse setting dialogs, others are not.

In your situation, I suggest you create a new library project, say "appLib", and put the common code in there. It contains only the code that is common to app1 and app2. Then add a project reference from app1 and from app2 to appLib.

Links like this may also be helpful: How do I include a jar file into a lib folder of an ear file using ant?

If you share a library like this, you might run into situations where you alter it because of a need in app1, and then you have to test app2 again because the edits have become visible to app2 and vice versa. Thus moving errors from one to another project. This may be very stressful. Finally, maybe it's best to have a versioned source code library for your library and to checkout and include the source into app1 and app2 project. So you can change one app and the library without disturbing the other app immediately, and then merge the sources into the library later controlled, avoiding disturbing side effects.

Hth :-)