Java serialization is convenient to store the state of Java objects. However, there are some drawbacks of serialized data: It is not human-readable.

Tight coupling between modules is a bad idea, and the worst form of coupling is cyclic dependencies between modules. Fortunately, there are a few techniques we can use to break the cycles. They are Callback, Escalation, and Demotion, and Im going to walk through some examples that show each of them in action. Then, once the dependencies are broken,...

Spring Roo is an rapid application development tool that helps you in rapidly building spring-based enterprise applications in the java programming language. Google app engine is a cloud computing technology that lets you run your application on Google's infrastructure. Using Spring Roo, you can develop applications that can be deployed on the Goog...

In Jonathan Giles's post An FX Experience Retrospective, he starts by looking at the history of JavaFX and focuses on "what has happened in the world of JavaFX" in 2011. I was highly skeptical of JavaFX prior to JavaOne 2010 (see here and here for examples), but started to think more positively about it after the JavaOne 2010 and JavaOne 2011 annou...

In my latest post I explained the reasons that can cause the java.lang.OutOfMemoryError: PermGen space crashes. Now it is time to talk about possible solutions to the problem. Or, more precisely, about what the Internet suggests for possible solutions. Unfortunately, I can only say that I felt my inner Jamie Hyneman from MythBusters awakening when ...

When we are in the learning phase of some technology, we always find the cleanest scenarios and examples in books and tutorials. It is perfectly logical because then we have to grasp the very core of the concepts involved, and we don't want to be confused by the imperfections coming from the real world. When we make the first steps in the actual i...

Ahoy, matey! Welcome back to my journal, where Ive been documenting my experience of building a geo-distributed app in Java from scratch. In the previous article, I broke down the definition of geo-distributed apps. If you missed that part of the journey, turn the page back to catch up.

Have you heard of geo-distributed apps? According to my statistics around 50% of us havent! Microsoft defines a geo-distributed app as an app that spans multiple geographic locations for high availability and resiliency. "Geo-distributed" is a relatively new term, coined around the time when many of us jumped on the cloud bandwagon and started bui...

We introduce a recipe for creating resilient Kafka consumers using Reactor Kafka. This approach is one that we've developed over time and incorporates the learnings from our experience with running Reactor Kafka - and all the challenges that come with that. The consumer described in this article provides at-least-once delivery semantics using manua...

This blog was started on August 1, 2002 — 20 years ago yesterday! It's amazing to look back at my first month of blogging and see how many times I'd post per day. Most posts are only a sentence or two with no comments because Roller didn't have that feature yet. Other fun facts: This blog has used Apache Roller and Tomcat from day one. I've ...

For the third year in a row, I took a long summer vacation thanks to Okta's unlimited vacation policy. In 24 hours, Ill be starting my summer vacation. @okta has an unlimited vacation policy and Im taking full advantage with a month off! 😃What will I do?🏔 A week in Alaska🤠 A RV trip to Montana🛶 A week-long rafting...

The data in any modern and distributed architecture, such as microservices, work as a vein in a system. It fits like a state in a stateless application. On the other hand, we have the most popular paradigms in the code, especially when we talk about enterprise OOP. How do you combine both archive and software design, primarily on Java? This articl...

When tracking a bug we need to take a two-pronged approach. Similar to tongs that wrap the buggy module from both sides and squeezes to find the problematic part. Up until now, we discussed tools that are very low level. Some can be used to debug system-level services. Today well discuss the other side of the stack but still a very advanced managem...

Ktor is an asynchronous web framework written in and designed for Kotlin, leveraging coroutines and allowing you to write asynchronous code without having to manage any threads yourself. Here is a bit more background information on Ktor. It is backed by Jetbrains, who are also the creators of Kotlin itself. Who better to make a Kotlin web framework...

gRPC gRPC is a high-performance protocol for Remote Procedure Calls over HTTP/2. It is mainly used for communication between micro-services, but it can also be used for requests from end-users using browsers or mobile devices just like REST or GraphQL. gRPC was designed by Google, and open-source implementation libraries are available for several p...

I've used JPA Criteria for many years. The main advantage is its type-safe approach (compared to JPQL), but the code is quite complicated and not always straightforward. Recently, I came across a Querydsl framework and I saw its benefits immediately. The main benefits for me are: Type-safe approach. Fluent API with SQL style - the code looks pre...

Java and Python may be a smart starting line to assess how to complete your forthcoming project. Selecting the correct language depends on your business because of the product(s) you plan to create. Its arduous to make up your mind that programming language can best suit your business objectives as you dont understand the technologies' strengths an...

Spring projects in general are opinionated: 80-90% of use cases are handled "by default", and code is often much more concise than would be required otherwise due to Spring's preference of convention over configuration. These and other "opinions" can result in dramatically less code to write and maintain and as a result, more focused impact. In the...

Patience Pays Off Plenty of computer enthusiasts are well aware of the use of JDev files to get the information that they need to be transferred around wherever they want it to go. That said, there are not as many people aware of the fact that the initial upload process on JDev files to the Netbeans can take a considerable amount of time. It is tr...

With IntelliJ IDEA supporting a fully-functional integration with Maven, you can automate your entire building process. The result is that you can create a new Maven project as well as easily handle multi-module projects.

Introduction If you are using the Java Persistence API (JPA) 2.0, you may be wondering what the AccessType setting is for and how it can be used. This article will explain what the AccessType setting does and how it can be used to improve your JPA experience. The Java Persistence API program is a standard interface for accessing databases in Java a...

Putting Together the Best of Both Worlds One of the things that people like so much about JavaFx is the fact that it has a suite of powerful tools used by designers and creators to get exactly the kind of look and feel that they desire from their creations. When used properly, JavaFX will change the way that you take care of your biggest technolog...

You've come to the right spot if you are trying to hack OpenJDK with NetBeans IDE. This article explains what OpenJDK with NetBeans is and how you can use NetBeans to create OpenJDK. But before we dive in, first things first:

A couple of weeks ago, we had a great time hosting the workshop you can see below with Vlad Mihalcea. It was loads of fun and I hope to do this again soon! In this workshop, we focused on Spring Boot performance, but most importantly on Hibernate performance, which is a common issue in production environments. Its especially hard to track since iss...

Context It could be a basic "Hello, World!" application or a complex banking solution like Stripe, but developing an application is a fascinating process. This process typically includes extensive testing and quality assurance to ensure that not only the requirements are met but also that the application is reliable enough for users to consume. Whi...

What Index Is and How To Use It in Java An Index is a structure that facilitates search in your data. Is a pretty general term and doesn't belong to some language or database. In order to explain it let's create a way to search users for specific criteria like name, id, birth date, etc. Quickly Searching Among Millions of User Entries Let's assume ...

This article was originally published on February 5, 2008. When a new piece of coding material comes out, the entire coding community tends to get pretty excited about it. They care because they know that it means that there are new applications that they can play around with, and it is entirely possible that there will be some incredible new creat...

This article was originally published on January 1, 2009. Java Just Got a Little Better Have you been struggling to use the Java system as it exists today? If so, don't worry, you are not alone. There are plenty of people going through the same troubles, and no one is pleased with the fact that they have to struggle as hard as they do just to g...

Our first completely new product in 20 years, we're finally able to tell you about it

What You Will Build You will build a full-stack chat application with a Java Spring Boot back end, reactive data types from Project Reactor, and a Lit TypeScript front end. In addition, you will use the Hilla framework to build tools and client-server communication. What You Will Need 20 minutes Java 11 or newer Node 16.14 or newer An IDE...

In this article, we would be looking into some of the ways to create docker images for a Spring Boot Application. As technology is growing, things have changed how applications that serve requests from end-user are deployed. Traditionally you would have a machine to deploy the application and decide on the configuration of the machine to keep the a...

Switch Expression Groovy has always had much more powerful switch statements compared to Java. Class case values, regular expression case values, collection case values, closure case values, or at th...

In a previous post we learned about the macros SV, SVI and SVD that return a string representation of variables with their name and value. Groovy 4 also added the NP and NPL macros that we can use to ...

Groovy 4 added some built-in macros that we can use in our code. A macro is code that will create new code. It does this by manipulating the Abstract Syntax Tree (AST) before the code is compiled. So ...

I've just made available the m27 AMIs for Tribblix. As usual, these are just available in London (eu-west-2).One thing I've noticed repeatedly while running illumos on AWS is that network stability isn't great. The instance will occasionally drop off the network and stubbornly refuse to reclaim its IP address even if you reboot it. It's not just Tr...