In order to become a good Java developer solid knowledge of Eclipse IDE, or whatever IDE you use, like Netbeans or IntelliJIDea, is a must. Java has been blessed with excellent tooling which turbo-charge application development. IDEs or Integrated Development Environment allows you to code, run, test, and debug from just one tool. They are an immense productivity booster. Since I have started Java development coding in Notepad, TextPad, and JCreator, I know how it feels to have the power of IDEs with you. There are three big IDEs in Java world, Eclipse, NetBeans and IntelliJIDEA. The first two are free, and the third one requires the license. I use Eclipse, and it's also the most popular IDE in Java world.