What are the most important things to learn about Java Programming?

java

Solution

Some things may have changed since you left the language, here some personal proposals:

- Servlets and JSP, you should take the dust off to this and include some EL (Expression Language)

- A build tool (Maven or Ant), most of Java application are now built with the help of them.

- Any Web Framework (Spring MVC, Struts2 or JSF are good choices)

- IoC and ORM (Spring and Hibernate are good choices)

- Take a look to Apache Commons and use them when possible

Also some features from Java 5+ like:

- Annotations

- Generics

Problem

I have a good understanding of object oriented programming but it's been a while since I programmed. I want to learn it again. What are the most important aspects of Java programming that are important to learn so I can identify myself as a programmer. I had trouble learning Swing before and I gave up but I want to try it again to learn it. How many years does it takes to be a good programmer?

Original source