AppServers, Grid, SOA, JEE, etc.

The term ‘java developer’ covers a wide range of individuals. It starts with fresh graduates looking for jobs and goes up till experienced Java Enterprise Edition developers. There are a wide range of concepts and skills that Java developers must posses in order to be important in the industry. It is highly advisable to know the language fundamentals thoroughly, rather than specific frameworks or syntax. The following websites will offer professional Java developers a storehouse of valuable information as also a platform to interact and prosper!

1.DZone - DZone

Place where community members discover and share the latest and most popular news from around the web. This community-driven page is carefully moderated by an expert editorial staff to ensure the content remains interesting and relevant.

2.LeetCode - LeetCode

LeetCode is a social platform for preparing IT technical interviews. The website provides code solution using the Online Judge system, high quality article featuring in-depth thought process and more.

3.Stackoverflow - Stackoverflow

Stack Overflow is a question and answer site for professional and enthusiast programmers. It’s 100 per cent free, no registration required.

4.Java SE Technical Documentation - Java SE Technical Documentation

Contains all documents you will need to use API of Java SE. It’s a one-stop shop for everything recent in the world of Java and it’s Oracle’s official website, so all the material here is 100 per cent geniune and update very frequently.

5.Coursera - Coursera

Coursera is an education platform that partners with top universities and organisations worldwide, to offer courses online for anyone to take, for free.

6.Java World - Java World

JavaWorld is the leading independent resource for enterprise Java technology developers, architects, and managers who want to learn more about Java and related technologies from professional developers and trusted industry experts. JavaWorld reaches the core audience of IT professionals who are planning, developing, deploying, and integrating Java-based solutions on an enterprise level.

7.Github - Github

Apart from hosting your projects for free, Github is also an excellent resource for learning popular Java libraries and frameworks with corresponding examples.

8.Program Creek - Program Creek

The website contains some very interesting articles written by people from different areas. The articles here are supported by relevant diagrams and code examples.

9.Wikipedia - Wikipedia

Our discussion will be far from over without the mention of this particular website that has been a store house of immense resources on practically any topic out there. You may just want to know some concept, but not learn much and the website will do you loads of good. Frequently updated information is available for free.

Java may not be the newest programming language around, but it is still one of the most popular. This is an Object Oriented Programming (OOP) language, which has become a mainstay in most enterprise and home projects.
Here are a few good design principles you should follow:

1. DRY
DRY stands for Don’t Repeat Yourself, which is pretty self explanatory. This means that you shouldn’t be duplicating your code in a program. If a code fragment is appearing in two places, then you would do well to turn it into a method instead of writing the entire fragment again. Lack of duplication helps in easy maintenance of the code.

2. Encapsulation

Whether your project gets bought over or whether you work on it yourself, your code will always change. So, it is good to encapsulate the part of the code that you think will be changed. This makes you code easy to maintain and test.

3. Design Principle

Here you should try and follow an open closed design principle. This means that you classes, functions or methods should be Open so that new functionality can be added easily. The Open Closed Design Principle focuses on this aspect and makes it possible to avoid unauthorised changes to already tested and working code.

4. Single Responsibility Principle (SRP)

According to this principle, a class should be handling a single functionality. In addition, there should be more than one reason for a developer to change a class from what it currently does. For example, if you have multiple functionalities in a class in Java then you might face problems when you are coupling this fake Java.

5. Dependency

The framework that you use already provides you dependence, which means that looking for it a additionally will be a waste of time. You can also use byte code instrumentation as well. Some Aspect Oriented Programming (AOP) framework already does this. Lastly, you can also make the use of proxies.

6. Composition over Inheritance

According to many programmers, composition is more important than inheritance. They say that you should be focusing on the composition of your program than on employing a flexible inheritance structure. This is because composition allows you to change the behaviour of a class at runtime. Interface on the other hand allows you to use polymorphism, providing the flexibility to replace something with better implementation.

7. Liskov Substitution Principle (LSP)

This principle states that you must be able to subtypes for super types. This means that any methods or functions in your program that are making the use of super class types, then they should also be able to work with the sub class. It is in close relation to SRP and the Interface Segregation Principle.

8. Interface Segregation principle (ISP)

This principle tells you to ensure that clients do not implement any interface that it doesn’t use. In Java, an interface has the disadvantage from the design point of view, to implement all methods before the classes can use it;

9. Programming for Interface

A programmer should always be programming for the interface and not for the implementation that will give them flexibility in code. Make use of interface types on variables and return types on methods. In addition, argument types should also be use.

10. Delegate

Delegate the tasks of your program to specific to classes. An example of this would be the equals () and hashCode() method.

Honestly, Java is the best thing that has happened to developers. The write-once, run-mostly-everywhere language is simply awesome. It is undoubtedly very stable and ubiquitous. However, all said and done, Java is not 100 per cent perfect. It does come with its own set of problems (not major, we say) that can be quite frustrating at the end of the day!
Here are 10 things we absolutely hate about Java:
1. Long CamelCase names
Gluing together long sentences in the form of variable names by capitalising the first letters might add a bit of self-documentation to the code. Many developers would agree to the fact, however some are even of the opinion that Long CamelCase names can be quite taxing. Take for instance, i // holds the interest rate before taxes as per regulation 43 is any day easier to read than interestRateHoldingVariableAdjusted ForTaxesAsDefinedByRegulation43, right?
2. Punctuation
The one thing that distinctly separates Java from others is the rampant availability of punctuation like curly brackets, semicolons, and parentheses. Although punctuation lovers might beg to disagree, most programmers are rather not very fond punctuation abundancy. They on the contrary see it as visual noise that in turn leads to a disconnect between the developer and the compiler.
3. Open source confusion
Ok, be honest, is Java open source or not? Of course developers might contend that the JREs and JDKs are freely available, but does that mean your safe? Developers around the globe live a under a constant threat of anxiety peaking out from countless imaginative legal repurcussions when using Java.
4. The Java thread pig farm
Node.js users constantly ridicule Java server platform saying that the Java thread factory is one big pig farm that adds 2MB of additional fat to the server RAM profile each and every time someone clicks on any supported Web link. During its initial days, Java threads were extremely lightweight when comapared to competing solutions.

5. Intolerably slow startup times

No one question the fact that Java apps run fairly smoothly upon start, what is painstaking is the start up. It’s exceptionally slow, a considerable issue for developers. For instance, Android app creators know and constantly fret about how slowly the simulator code runs on the desktop.

6. Endless checking for null pointers
This is perhaps one of the most frustrating aspects of Java. It requires countless ‘if’ statements to check if variables ended up null. Well, if they did not, the entire Java thread would eventually crash with NullPointerExceptions.
7. Object creation overhead
Tossing everything into an object might seem ‘effective’, however, those who do it know how slow the process of creating a Java object can be. Furthermore, the process is expensive. Notably most programmers who aspire to speed up coding more often than not tend to avoid the object-oriented model.
8. Primitive wrappers to use data structures
The Java data structures are pretty neat, however the only downside is that they require programmers to wrap their basic values in objects to use them. This turns a four-byte ‘int’ into a big, fat object.
9. Strings are big, need overhead, and are final
Strings are objects that can’t be changed. Its highly advisable programmers get them right the first time. In case you go wrong somewhere, you will have to create an entirely new object and copy it all over.
10. No global variables
Absence of global variables entails in programmers creating Global class and fill it with static variables. Meanwhile, others build singleton objects, however there are serious issues about efficiency here.