Some Basics on Java and Where to Download the Compiler and SDK
Java is an fully Object Oriented programming language. It is also os architecture independent, secure, and high level. Anyone with basic knowledge of programming and some understanding of object oriented characteristics (abstraction, polymorphism, encapsulation, …) can learn the basics quickly. Java source code is saved with the *.java file extension. Once compiled, it becomes a *.class file extension (called bytecode). A *.class file is os architecture independent, meaning that it can run on Windows, Mac, Linux, and other variants of Unix. The Java Virtual Machine (JVM) must be installed on your system to interpret the bytecode and change it into machine code the system can understand. Executable programs have the *.jar extension.
You can code using any text editor, although you will find it very useful to use a software development kit (SDK) such as NetBeans, Eclipe, JBuilder, and many others. Some of the SDK’s are free, while you have to pay for others. Most paid SDK’s are more powerful and flexible than free ones. If you are a beginner, you don’t need the paid versions for now. Download the most recent version of NetBeans here, or the most recent version of Eclipse here.
If you use a text editor, you will need to download the compiler, found here. This is the most recent version of the Java Development Kit (JDK). If you are using an SDK, the compiler comes with it, so you don’t have to worry about downloading it. With the JDK, you have to go and compile/run your codes from the command prompt, with the “javac” and “java” commands. You can find the full documentation for JDK 7 here, online or offline.