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Updated: 8 hours 31 min ago

The Java 8 API Design Principles

9 hours 30 min ago

This article is featured in the new DZone Guide to Modern Java, Volume II. Get your free copy for more insightful articles, industry statistics, and more.

Anyone that writes Java code is an API designer! It does not matter if the coders share their code with others or not, the code is still used; either by others, by themselves or both. Thus, it becomes important for all Java developer to know the fundamentals of good API design.

Categories: Java

Java 9 Kickoff: Project Jigsaw (Part I)

10 hours 30 min ago

Java 9 comes with a great feature called "Jigsaw," which modularizes monolithic Java code into modules, allowing us to design independently standard modules within different scopes. The primary goal of “jigsaw” is to enhance scalability, maintainability, performance, security, etc. For more information please click on this link.

Today, we're creating a greeting, using project “Jigsaw” to modularize our code independently.

Categories: Java

Software Development Via Functional Programming

11 hours 30 min ago

When I started my career back in 2009, I had to work on an IVR (Interactive Voice Response) application developed in Java. It was a lightweight server-side application but after some time, the way it was structured as well, was not able to evolve well. Code and configuration duplications, being unable to use the same call flows with minor changes as per client request, without refactoring, or in some cases like tight deadlines, developers resorted to duplication. So after some time, a very simple application became a nightmare to manage and maintain.

At that time, an initiative was started to cope with this. I thought of an application design and even created a PoC. The idea is to develop smaller configurable independent functions based on an interface having a single abstract method (SAM). Such functions would represent a unit of work just like a class method in Java. To what level of detail a unit of work is defined is up to the implementor. But such functions shouldn't be broader in the sense that they perform multiple tasks in a single implementation or perform very minute tasks.

Categories: Java

Ready Your Java 8 Reactive Apps Now, Reactor 3.0 GA Is Out!

13 hours 29 sec ago

After more than a year of work, multiple milestones and fine tuning based on much feedback, I have the pleasure of announcing Reactor 3 General Availability. You will find Reactor Core 3.0.2.RELEASE on Maven Central.

What is Reactor 3?

Reactor 3 provides a powerful and efficient reactive programming model for Java 8 based applications. The model builds upon the experience of both Reactor 2 and RxJava 1 and introduces a fluent way to compose asynchronous backpressure-ready event processing. Spring Framework 5 uses Reactor 3 to build and eventually expose a complete reactive story.

Categories: Java

The Java Web App Journey... SOAP Services (Part 4, Finale)

14 hours 35 sec ago

We have a somewhat working SOAP service now.  Let's continue from where we left off in part 3.

You can get the code used in this article from the bottom of the previous article.

Categories: Java

A Beginner’s Guide to Java Internationalization

Thu, 2016-09-29 14:01

When developing software or websites today, an essential consideration is the global marketplace. As the growth of software products for global markets continue, it has become critical for companies to design products that interact with users in their native regions and languages. Software developers working on software for foreign markets should be aware of each market’s customs and differences. Some of these differences can include language, punctuation, currency, dates, times, numbers, and time zones.

If the software will be used in international markets, the initial software design should include planning for the international requirements, such as the target market, language, and the level of the internationalization effort required. Figure 1 shows a typical internationalization and localization process during the standard software design, development, and testing process.

Categories: Java

ReentrantLock Cheat Sheet

Thu, 2016-09-29 12:31

The ReentrantLock is a replacement for the easier-to-use synchronized statement when you need one of the following advanced techniques: lockInterrupibly, tryLock, lock coupling, multiple conditions, or fair locks.

In the cheat sheet below, I summarized each technique. And in the rest of this blog post, I give a detailed description of those techniques.

Categories: Java

The Java Web App Journey... SOAP Services (Part 3)

Thu, 2016-09-29 11:01

We left off in part 2, where we had conducted an initial, successful test of the generated WSDL using SOAPUI. Now, it's time to continue continue...

There is a link to the latest code at the end of this article.

Categories: Java

Language Flavors

Thu, 2016-09-29 10:01

It might be having a child in Spanish this year, or maybe it's the fact that I've been switching from Java to Ruby to Go to Python over the past couple months, but I've been giving some thought to how different languages are "flavored." One of my favorite things about the Go programming language is that the second thing you read while learning it is a whole book on "writing clear, idiomatic Go code."

I really like the term "idiomatic" in this context. It means both "natural to a native speaker" and "appropriate to the style." But most importantly, it comes from the root "idiom." One way to describe an idiom is that it means something different from what it appears to mean.

Categories: Java

One Gradle Plugin to JAR Them All

Thu, 2016-09-29 09:31

You have to pack a standalone application into one JAR that will contain your custom code and also all of the third-party libraries the code needs to function properly. You are using Gradle for your build scripts. The solution to this task has two steps.


Create a Gradle build that will compile and package your standalone application. The solution to this first problem it is easy if you are using Eclipse + Gradle Buildship plugin. After installing the plugin, you will be able to create a Gradle project from Eclipse with a generic build.gradle script.

Categories: Java

Java Code Challenge: Wandering Fingers

Thu, 2016-09-29 08:31

The Java Code Challenge is a regular segment taking the best challenge from Reddit's dailyprogrammer. Things are a little different here, as we're focused purely on Java. A working solution is not enough; we're looking for the cleanest Java code with tests. Third-party libraries are welcome, but if you can do it without it will be easier for others to comprehend.

If you can fit your solution in the comments then go for it, but preferably put your answer in GitHub and link in the comments. Next week we'll be sharing the best solutions and sharing the best code practices we see!

Categories: Java

JavaZone 2016 (And Why You Should Go Next Year)

Wed, 2016-09-28 13:31

It’s been a while since I wrote a conference write up. The short version of “why” is because I got a bit bored of doing it. Plus, I found I was attending conferences as a speaker “on the circuit”, and my experience of hanging out, catching up with my friends, chatting to other attendees to see what they’re up to and so forth, didn’t seem as useful to share with people who might want to find out whether a conference is worth attending from a content or atmosphere point of view.

But I feel compelled to blog about JavaZone. I presented there back in 2013, but every year since then haven’t made it for one reason or another (the fact that it’s near my birthday in no way impacts my scheduling…). I made the effort this year, and I’m so pleased. Now I’ve been to many more conferences, of various sizes, various themes, all around the world, and I can definitely state that JavaZone is up there as one of the best conferences around.

Categories: Java

The Java Web App Journey... SOAP Services (Part 2)

Wed, 2016-09-28 12:31

In part 1, we did most of the setup of our new web service project, and we were able to generate an initial WSDL. Now we want to deploy something (even if minimal) to our Eclipse Tomcat server — so we are jumping right in from where we left off.

Java Config

We completed a web application (it used the Shape Calculator) that we covered over several articles, and here is where we began to discuss doing configuration with Java instead of XML. I will just take what we have already done in the past as a starting point and go from there.

Categories: Java

Creating Maven Artifacts From a jar File

Wed, 2016-09-28 11:01

Today, we're going to create an artifact from mailapi.jar with version 1.4.5 and use it in our Maven project. This article will guide you through the steps to make that happen.


While creating Maven projects, we often come across a scenario when we have to import a jar from local repositories instead of Maven.

Categories: Java

Jackson Mixin to the Rescue

Wed, 2016-09-28 10:01

Many-a-times it's not possible to annotate classes with Jackson Annotations simply for serialization/deserialization needs. There could be many reasons, for example:

  • Classes that need to be serialized/deserialized are third-party classes.
  • You don’t want Jackson invading your code base everywhere.
  • You want cleaner and more modular design.

Jackson Mixin would help solve above the problems easily. Let's consider an example:

Categories: Java

Object Identity and Equality in Java

Wed, 2016-09-28 08:31

In this article, I will discuss Object Identity and Object Equality in Java.

Object Identity

When we create objects in Java, the computer stores them in its memory. To be able to locate an object, the computer assigns it an address in the memory. Every new object you create gets a new address. If this yellow area represents an area of the computer’s memory, the blue area represents our object being stored in the memory. This object will be given some sort of address.

Categories: Java

Debug Like a Champion

Wed, 2016-09-28 07:31

As Pareto’s Law says: Software development is 20% of the time developing and 80% debugging.

Imagine how powerful you could become if you cut down the debugging time and made the debug process more efficient, finding the root cause of the problem in your code or understanding the workflow of your algorithm.

Categories: Java

My Journey in Scala, Part 3: None Is Better Than Undefined

Tue, 2016-09-27 14:01

Here’s the situation: At Threat Stack, we consume a torrent of security event data every day, and as many new customers come on board, the amount of data we need to ingest, transform, store, and retrieve just keeps growing. About a year ago, we implemented a caching layer to allow us to display more aggregated information to customers on our Dashboard, which was powered by ElasticSearch Aggregates.

Fortunately, our Ops team has given us the ability to metric almost anything, which enables us to predict and see the pressure we are putting on our cluster. With the aggregates from ElasticSearch, we are essentially trying to solve a counting problem, and therefore, we turned to another service we use internally: Apache Spark.

Categories: Java

The Java Web App Journey... SOAP Services (Part 1)

Tue, 2016-09-27 12:31

Our continuing make-believe story:  You work in a team of developers, and some time ago, you took some code that was very useful to you (albeit somewhat simple), and you realized it might be resuable. You made it into a separate project, and later, you wrapped it in a simple command-line application. Some of your teammates saw it and suggested you should have it persist the data, which you did, also delivering round two of the improved command-line application.

Later on, other people either in your department, or elsewhere, asked if you could web-enable it, as they weren't "command-line savvy."

Categories: Java

Gradle 3.1: Composite Builds, Here you Go!

Tue, 2016-09-27 11:01

Our journey with Gradle started one and half years ago with this presentation. Everybody in the company just loved its expressive and easy-to-understand structure and realized that a plugin model was the wrong level of abstraction. Instead, language-based approaches were the right one in terms of their flexibility for the long term.

So it didn't take long for almost 50 members of the development team to change the whole build infrastructure with Gradle. Gradle doesn’t just throw away the foundation that other build tools brought. Instead, it builds up easily and more powerfully on top of others while remaining 100% compatible with them. Therefore, this made Gradle not an alternative but an upgrade for us.

Categories: Java