Please don't post "spam" or "Thank you" posts in this thread since this is meant to be used as a guide for all beginners and I am sure we would like it to be on topic. I hope you understand this.
» Introduction to Java «
To start off, Java is a general purpose programming language liked by application developers and web developers alike. It is the force which drives a large number of enterprise applications out there. Read more about it here. And yes, just for the records, Java is not slow!! [ 1 , 2 , 3 ] ;-)
» Getting started «
All you require to develop Java application is a text editor and a JDK which encompasses a Java compiler, a Java Virtual Machine and a host of tools which ease your development. Some handy links (ignore the specifications for the time being):
After installing the JDK, you might want to take a look at the common problems beginners face when setting up Java and their solutions.
As a beginner, you should know the commonly used JDK development tools like javac, java, jar, javadoc to name a few. Read about them here.
There are a lot of IDE (Integrated Development Environments) out there which greatly reduce the development time and abstract away all the complexities like compiling classes manually, setting up the classpath etc. Though bear in mind that IDEs are not a substitute to understanding how everything ties out under the hood so once you are comfortable with the language, do ensure that you try out things with a text editor. A few free and commercial IDEs are:
» Eclipse IDE [open source]
» IntelliJ IDEA [commercial and free community version]
» Netbeans IDE [open source]
» JCreator [both free and commercial versions]
» Build Tools «
Though compiling Java programs using the
javac tool or an IDE may seem fine enough now, it has its limitations. Compiling, building and deploying an entire application using repetitive commands becomes quite tedious. Build tools to the rescue! It is a good thing to have the knowledge of at least one of the build tools under your belt if you want to work with Java in a professional setting. There are a lot of open source build tools out there, Ant and Maven being well known among them. Which build system to use is a personal / project choice though Ant is a good one for beginners.
As those who don't mind writing their build scripts in a scripting language rather than the verbose XML, Gradle looks promising and has a decent userbase.
» Unit Testing «
It's a good thing to get into the habit of unit testing your code. Test cases have a host of advantages over your normal print statements placed throughout your program. Testing helps you in focus on the way your Java object is actually used / the part it plays in the system, thereby improving class design. And above all, its fun. :-) Get the unit testing framework JUnit here or the more recent TestNG Google for 'junit tutorial' and you will surely find something to get you started.
If there is talk about Unit testing, mocking deserves a mention. In simple terms, Mocking provides a mean to simulate your external dependencies in unit tests. As an example, your payment gateway might need to reference a "service" class which sends across a message to an external entity (for e.g. a bank). To unit test this functionality, it is not feasible to send a message since it would count as a stateful transaction. To get around this, your unit test can "mock" out the service and hence the service call during unit testing.
» Links «
When it comes to Java tutorials, there are plenty of tutorials floating around, most of them wrong in a multitude of ways. I would recommend starting out with the official Oracle tutorial.
Some free online books / pdf's:
» Think Java
» Introduction to Programming Using Java, Seventh Edition
» Thinking in Java 3rd edition
» Free java books
» Free java books at Developer's Daily
» Onto Java
In case you need to buy a book, consider the ones enlisted below. They are a gem.
» Head First Java 2nd edition[beginner]
» Java Programming Language [advanced]
» Java in a Nutshell [intermediate]
» Hardcore Java [advanced]
» Java concurrency in practice [advanced]
» Effective Java [advanced]
» Growing Object-Oriented Software Guided by Tests
» Clean Code: A Handbook of Agile Software Craftsmanship
For those more interested in watching videos rather than reading books:» Java programming on Freevideolectures
Generic Tech sites:
» Frequently Asked Questions «
» How can I convert a java program to an executable?
» Differences between Java and C++
» What is hell is 'Generics' all about?
» Extending Java with Type Parameters
» Where can I find a more comprehensive FAQ?
» Does Java support pass-by-value or pass-by-reference semantics ?
Just google for 'java faq' and you surely would stumple upon a gold mine of well written FAQ's.
» Certifications «
After getting a good grasp of the subject, you might want to get a good certification to add a feather to your cap. You can find more about Java certification here. Google for 'scjp notes', 'java mock test' or 'scjp mock' to get started. Getting a certification or not is a choice you have to make.
» Of programming and hackers «
The learning process remains incomplete unless we play around with the language, learn to understand others code and implement some sample projects. For those want to learn Java really fast, Teach yourself programming in ten years would be a good read. Some other inspirational reads are ' How to become a hacker ', Great Hackers and other Paul Graham essays . One of our community members, Black Box , has written a nice post targeted at beginners, which enlists what it takes to learn a language.
That being said, you can find a lot of open source Java projects on Java source . Play with them to your fullest, try to see how things are done in the real world and walk the path of a hacker! ;-)
» Game Development «
The Java Monkey Engine makes 3D game dev possible with advanced features like shaders, cloth simulation, bump mapping, inbuilt sound and user interface support and much much more. You can learn more about it on the JMonkey Home page.
Given that 3D game development can be a bit daunting for entry level game programmers, there's an excellent 2D game engine called libgdx worth looking into.
» Epilogue «
It has taken a lot of effort to come up with these links so that you don't waste your time searching for some study material / reference text. Appreciation goes out to Stephen , Ezzaral , Peter , Alok and others for their suggestions and corrections. So, just go for it, learn, contribute to this thread and above all, enjoy programming!
Java FTW! :-)