Becoming a Junior Java Developer 101

by | Jul 22, 2019 | Aggregated |

Hello everyone,

in order to become a Java developer you don’t need much ;), however if you start learning everything you probably will be overwhelmed and will focus on the wrong bits and basically will probably give up.

However I have to say DON’T give up. Java is extremely easy language, maybe the easiest to start with, it is the most easy language to understand and to read (in case someone else has written the code) so this is the primary reason why Java is the most commonly used language.
The issue with JavaScript is ones you learn the language and bits of the SDK (Standard Development Kit) you will be overwhelmed by a HUGE number of Libraries and Frameworks, you will not know what to learn and how to combine and how to connect different frameworks in order to have a finished product.

So I hope this guides will give you some direction and by reading and understanding EVERYTHING in this guide you should be more than ready to join some company as a Junior Java Developer. All materials are completely FREE and are far better then any academy or university course and etc.

Why you will choose an Academy or University or Udemy course ? The only reason is if you are lazy. You see in order to understand and start applying something you need to first learn it and then to use it to write something. Most people just read without the writing bit, or try to write before they have learned anything (which is better case then the first in my opinion) but in both cases this creates a huge, HUGE gaps that are usually caught on an interview and basically makes you to fail. Academies and udemy courses help in a way that they explain and repeatedly tells you the same things over and over again and this combined with homeworks and exercises helps. Also especially udemy courses by being very pragmatic and practical will show you a code that otherwise you have to write which helps the lazy people a lot.

Still my advice is first read this if for some reason you see you are lazy and dont write code and dont do exercises and need a push then buy some udemy course for 10 bucks, if this also doesnt help then look for an expensive academy which for me should be the last resort and not the first one.

OK where should I start?

1) The best plays to start are the official Java tutorial (they are a bit outdated but still they are the BEST to start from, I started with them as well back in the 2005 and they have been updated since then but not as much as I would want to)

https://docs.oracle.com/javase/tutorial/


  • Getting Started — An introduction to Java technology and lessons on installing Java development software and using it to create a simple program.
  • Learning the Java Language — Lessons describing the essential concepts and features of the Java Programming Language.
  • Essential Java Classes — Lessons on exceptions, basic input/output, concurrency, regular expressions, and the platform environment.
  • Collections — Lessons on using and extending the Java Collections Framework.
  • Date-Time APIs — How to use the java.time pages to write date and time code.
  • Deployment — How to package applications and applets using JAR files, and deploy them using Java Web Start and Java Plug-in.
  • Custom Networking — An introduction to the Java platform’s powerful networking features.
  • Generics — An enhancement to the type system that supports operations on objects of various types while providing compile-time type safety. Note that this lesson is for advanced users. The Java Language trail contains a Generics lesson that is suitable for beginners.
  • Internationalization — An introduction to designing software so that it can be easily adapted (localized) to various languages and regions.
  • JavaBeans — The Java platform’s component technology.
  • JDBC Database Access — Introduces an API for connectivity between the Java applications and a wide range of databases and data sources.
  • Reflection — An API that represents (“reflects”) the classes, interfaces, and objects in the current Java Virtual Machine.
I would focus only on this topics and I would not read everything. Also on the generics bit do not give up, if you lose the focus half way threw just skip it and continue with it at the end of the list. I actually skipped half of it for at least an year initially and went back an year later to reread it, they are just hard and crazy and messy and hard to learn without practice. 

Ones done I would read some SQL, it is a standard language for querying and storing and manipulating data in relational databases which are widely used and which you already have probably used in the JDBC Database access bit of the links above. So if you want to learn more just read the w3c tutorial https://www.w3schools.com/sql/ 

2) Now you are done with the CORE Java, you know what most University students know about Java, you  know more about Java then any other core course that exists and here is where it gets tricky. You see after this point you have to decide what to do and there are 3 options where I would recommend just 1.
 Option 1 is to become an Android Developer, to write apps for Android and to basically be a Mobile Developer.  Recently Google made Kotlin language first and they announced Flutter where the apps are written in Dart, so I would not advice to go this road. Still if you want to write apps for your mobile android phone start with https://developer.android.com/guide or https://www.tutorialspoint.com/android/
 Option 2 is to become a Java Enterprise Edition developer. I would say this is also risky, first of all Java EE 8 will be the last standard Enterprise Edition version of the Java EE, there will be Jakarta EE 9 which is a non standard, eclipse foundation lead endeavour to continue the development and innovation in the Java Enterprise Edition, however no one knows how used Jakarta EE will be, also even this days the Java EE is not that used so I would simply ignore this option If I were you, at least for now.
 Option 3 is to become Desktop developer, however the Java desktop apps are dead and I would not bother with them, you have several options SWT, Swing and JavaFX but none of them is used that much, there are no many jobs in the area and I would not recommend you to go there.
 Option 4 This is the ONLY option you have. You see currently 90% of Java developers are writing Web applications in the enterprise space which uses Spring Frameworks and parts of the Java EE which parts are focused on the web side of things. 

The guide and links and tutorials look like this:
https://docs.spring.io/spring/docs/4.3.16.RELEASE/spring-framework-reference/htmlsingle/ the spring reference guide is amazing but keep in mind you don’t need all from it.
I would read everything from the beginning to the Aspect Oriented Programming (AOP) part.



Now you should be able to build a non web spring application but you will need Spring web after that
For the view layer I would read only JSP https://docs.spring.io/spring/docs/4.3.16.RELEASE/spring-framework-reference/htmlsingle/#view-jsp  why ? Because most companies even today still uses JSPs for their views and not thymeleaf or etc. So if you need a SERVER SIDE rendering this is the way to go, otherwise you will do a JavaScript client side rendering but this is not for Java Developers to work on, so the JSPs views are completely fine for a Junior developer.
Voala thats all I would also read about JSP Expression Language and JSTL https://www.tutorialspoint.com/jsp/jsp_expression_language.htm which are heavilly used in a the  JSPs.
Thats all, in reality it should not take you more than a month to read it all, you should have created several examples and projects with this technologies and highly recommend to push them all in github.com . This days no one is actually reading your CV, most people just check what you have written in github especially for Junior Developers. And yes you will need git in order to push and publish your projects for the world to see https://git-scm.com/book/en/v1/Getting-Started-Git-Basics

That’s all folks. I hope this will be helpful for some of you.