Java

When you start a new project in Java, obviously you are not going to use only plain vanilla Java. You usually need some libraries or frameworks to help you: maybe to connect to a database, maybe to setup some web service. There are many of these libraries and frameworks that have been around our Java ecosystem for a long time. They have helped evolved the Java ecosystem for decades. These libraries experiment with features and how to implement them in the best way. That generated a knowledge base that the developers of the language can later use to add those same features in the best way possible to the core language. ...

A year ago I started with a couple of friends a new project based on Quarkus to create a visual editor for integrations called Kaoto. As responsible of the backend side, I obviously chose Java to do it. Coming from the Java 8 world with shy traces of Java 11, I decided to jump directly to Quarkus on Java 17 (unstable at the time) with Reactive and explore the serverless possibilities while, at the same time, keep the over-engineering and the over-fanciness of new features as reasonable as possible. On this article I will discuss the good and the bad of this experience. I am not a Quarkus developer, I am a developer that used Quarkus. And as any average developer that starts with a new technology, I obviously skipped the documentation and just bungee jumped into the framework, blindfolded and without safe nets.

I would like to present you with an ETL and integration editor Rachel and I have been working on for the past year with the initial help of Zineb: Kaoto. What is Kaoto? Kaoto is an integration editor to create and deploy integrations in a low-code way and no-code way based on Apache Camel. It combines a source code editor and a drag and drop graphical space synchronized with each other. It can be run both as standalone and as a service (SaaS). With the no-code mode, the user can build the entire integration orchestration with the drag and drop function. Kaoto has a step catalog with a list of all available building blocks that the users may want to transform data or integrate with services.

This post was originally posted on the blog of a former company. But since they have decided to violate my authorship rights, here is a copy of it. We have already seen how to compile and run a basic GeoNetwork instance. Although we know that real developers will probably skip this step too, for new developers in GeoNetwork, it will be relief to have an IDE to work with. I know that many GeoNetwork developers use NetBeans or Intellij but as I am used to work with Eclipse, that’s what we are going to explore on this post. First of all: Eclipse has better support for Maven projects on each version. So, to avoid headaches, just download the latest eclipse available.Eclipse has many installer tutorials, so I won’t stop here explaining how to run eclipse. I will just assume you know how to do it. To run GeoNetwork from eclipse is very very easy. Just right click on the Package Explorer view to import -> As Maven Project over the folder you already had cloned on the last post:

This post was originally posted on the blog of a former company. But since they have decided to violate my authorship rights, here is a copy of it. GeoNetwork, your friendly spatial catalog, never has been an easy software to deal with. But specially after the 3.0 version release, many things have changed. On this series of posts we will try to help new developers start with it. The source code is available on a public repository on Github. This means that you can clone, fork and propose pushes of your custom changes. If you are not familiar with repositories of code or git, you should check this quick manual.

GeoNetwork is a server side application that allows you to maintain a geographic referenced metadata catalogue. This means: a search portal that allows to view metadata combined with maps. GeoNetwork logo Based on Free and Open Source Software, it strictly follows different standards for metadata, from Inspire to OGC. It implements the CSW interface to be able to interact with generic clients looking for data. It also has built-in harvesters to connect to other servers and populate data. ...

Annotations on the code or decorators have become very common. They allow the programmer to add additional useful information about how to improve the code or change how to compile / run a particular class. They are a Java extension to allow aspect-oriented programming. We have three types of annotations based on the moment of usage: Information for the Compiler These annotations allow the compiler to indicate whether or not to ignore errors and warnings or what to do with them. If you’ve worked with a Java IDE (like eclipse) probably you would have used this type of annotations. For example, you can use @Override on a function to indicate that you are overwriting a method defined on a parent class. ...

This are the notes that I took over gvSIG 2.0 on the latests Jornadas GvSIG. Pre-requisites Java Eclipse Ant (should) Maven (should) gvSIG (this is recursive :)) The main advantage of gvSIG 2.0 is that you can create a new plugin without knowing how does gvSIG work or having to compile it. We already have a gvSIG installation that deploys the binaries to the workspace. But we don’t have to change the source code. Unless, of course, something doesn’t work (bugs) or we have to add some new functionality to the core. Better if you don’t touch it, ask the developers and they will take care. ...

When facing high concurrency applications, we often find a number of generic problems. In this article I will focus on the problems of resources (CPU and memory). For now on, I will focus on the most typical and most direct solutions. When we discover threads and the advantages of parallel processing it can happen that we end up abusing their use. We have a lot of threads (100 ¿? 1000?) simultaneously, and the processor will be jumping from one to another without stopping, not letting them finish, no matter how fast is their real excution. And over time there will be more and more threads only slowing down the process. To the cost of execution of each thread, we must consider also the added cost of creating and destroying threads. It can can become significant when we talk about so many threads at once. ...

Sometimes you don’t know where to start when you enter the world of GIS programming. Too many libraries, IDEs, but the truth is, everyone assumes you already have a base and everything become chaos. Something is easy as how to develop a map on Java has scarce documentation. If you have absolutely no idea of GIS, I would recommend you start by the Free book of Free GIS by Victor Olaya. ...