Build vs Deploy vs Publish (Eclipse IDE)

Question

I'm a newbie to J2ee though not a complete newbie. I'm unable to find a good resource (book or video) that could help me understand what exactly happens when we build, deploy and publish. I have a fair idea though. So my questions are -

1. Is there a good resource out there that can help me understand these concepts? I've read some books on struts and servlets/jsp but they don't delve into eclipse and how/what it does. The eclipse documentation has been helpful but only slightly.

2. When we build an application the the java files are converted into the class files and stored in the java build path. What else happens during build? Many people use the term 'library dependencies', what does this mean? Also, when people refer to dependencies do they refer to files like xml and tld?

3. At what stage (build or run on server) does the container check to see if the dependencies are alright? Say for instance, if the servlet class/name in the web.xml file.

4. Is it appropriate to say that build is basically compilation while deploying the project and running it is the same as executing it?

Answer 1

Familiarity with the servlet specification would help you (perhaps some older version would be quicker to read like 2.4), but general understanding of what you build and how you do it in Eclipse is what you are after.

The way I see it is that during the build Eclipse creates almost complete version of WAR (or some other archive, if you use EJBs for instance) and by publishing you deploy it to some server (this is practically the same thing although Eclipse might just configure the server to use exploded WAR that it just prepared instead of copying it to some "deploy" dir that you are supposed to do if you work without an IDE). If you configure your project well, the build can only mean compilation, but if you have more ceremony in it, then some source generation and moving files around might happen too.

To address your second question, library dependencies can be files that reside in WEB-INF/lib for instance. Read the spec to know what should be there and what should not. Eclipse tries to copy there all defined dependencies of your project.