You might want to change the behavior of a Java application at runtime without having to alter the original sources and recompile them. This can be done by using a Java Agent. Java Agents are used by several products. Dynatrace uses for example a Java Agent to collect data from inside […]
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Quickly Run NodeJS Demos in Vanilla Windows Sandbox featuring Scoop
TL;DR – this article describes how Windows Sandbox can be used to prepare a well known environment for demonstrations, tutorials, tests etc. Scoop is a great package manager for quickly installing Windows packages (Node runtime, Git client, VS Code editor, …) into the Sandbox. I have applied these concepts to […]
Run Automated Step-by-Step Browser Scenarios for Instruction or Demo from NodeJS applications with Playwright
TL;DR; Run demonstrations or instructions of browser actions. Allow the user to pause and skip acts, and to reset and switch scenarios. Allow the user to interact with the browser before, after and during the scenarios. The open source Playwright library is used from a custom NodeJS application in which […]
How to APIfy WhatsApp – Programmatic interaction with WhatsApp from Node using Playwright
Sending WhatsApp messages from services and applications has been a frequent request from our customers. It also was something I would have liked to use in workshops and demonstrations. It appeals to people. However, WhatsApp does not provide an open API for sending or receiving messages. There is a business […]
How to dynamically Schedule EM Blackouts after PatchTuesday
In the organization I’m currently working for, the OS-patch schedule depends on PatchTuesday (PT) just as Microsoft, Adobe or Oracle are using. And PatchTuesday is, as you all know, the Second Tuesday of each month. But this is a schedule you can not set in the Oracle Enterprise Manager Scheduler. […]
Jenkins Pipeline: SonarQube and the OWASP Dependency-Check
The OWASP Foundation plays an important role in helping to improve security of software worldwide. They have created a popular and well-known awareness document called the ‘OWASP Top 10‘. This document lists the following risk: using components with known vulnerabilities. Software nowadays can be quite complex consisting of many direct and […]
Quarkus – Supersonic Subatomic Java, trying out Quarkus guide “Quarkus – Kubernetes extension” (part 3)
In this article, you can read more about the Quarkus code guide I tried out, related to the following topic: The ability to automatically generate Kubernetes resources by Quarkus The guide covers generating and deploying Kubernetes resources based on sane defaults and user supplied configuration. In this article, I will […]
Quarkus – Supersonic Subatomic Java, trying out Quarkus guide “Quarkus – Kubernetes extension” (part 2)
In this article, you can read more about the Quarkus code guide I tried out, related to the following topic: The ability to automatically generate Kubernetes resources by Quarkus The guide covers generating and deploying Kubernetes resources based on sane defaults and user supplied configuration. In this article, I will […]
Quarkus – Supersonic Subatomic Java, trying out Quarkus guide “Quarkus – Kubernetes extension” (part 1)
In this article, you can read more about the Quarkus code guide I tried out, related to the following topic: The ability to automatically generate Kubernetes resources by Quarkus The guide covers generating and deploying Kubernetes resources based on sane defaults and user supplied configuration. In this article, I will […]
Jenkins: Building Java and deploying to Kubernetes
Kubernetes is a popular platform to run and manage containerized applications. A CI/CD solution is often needed but not always provided. You might need to set this up for yourself. In this blog post I’ll provide a minimal end-to-end solution for Java applications. This starts with a commit in source […]
My Steps for Getting Started with Java Development on Windows
In this article a brief overview of my steps to set up an environment on my Windows 10 laptop for doing Java programming. If you follow these steps, you should be up and running with coding, building, testing and packaging Java applications on your laptop in some 20 minutes. The […]
Quarkus – Supersonic Subatomic Java, trying out some Quarkus code guides (part2)
In this article, you can read more about a Quarkus code guide I tried out, related to the following topic: Packaging the native executable in a container In a next article, you can read more about another Quarkus code guide I tried out, related to the following topic: The ability […]
Quarkus – Supersonic Subatomic Java, trying out some Quarkus code guides (part1)
In my previous article, I already shared with you the Quarkus code guide “Quarkus – Creating Your First Application”, I tried out, including the hot deployment with background compilation. [ https://technology.amis.nl/2020/08/21/using-vagrant-and-shell-scripts-to-further-automate-setting-up-my-quarkus-demo-environment-from-scratch-and-trying-out-a-quarkus-code-guide/] In this article, you can read more about other Quarkus code guides I tried out, related to the following […]
Using Vagrant and shell scripts to further automate setting up my Quarkus demo environment from scratch and trying out a Quarkus code guide
In my previous article, I shared with you the steps I took, to set up a demo environment, so I could get started with Quarkus. [https://technology.amis.nl/2020/08/17/quarkus-supersonic-subatomic-java-setting-up-a-demo-environment-using-vagrant-and-oracle-virtualbox] In this article, you can read more about the steps I took to further automate setting up my demo environment and the Quarkus code […]
Quarkus – Supersonic Subatomic Java, setting up a demo environment using Vagrant and Oracle VirtualBox
In November 2019, I attended Devoxx Belgium together with other AMIS colleagues. The yearly gathering of over 3000 Java developers (numbers provided by Devoxx website) were Java and software development are the core themes. At Devoxx, among other things, I learned about Quarkus and wanted to know more about it. […]
Quickest route to Your First Handson Experience with GraalVM – Katacoda Scenario with live environment and step by step tutorial
TLDR: This Katacoda Scenario has a live runtime environment with GraalVM 20.1 prepared for you including an easy to click-through step by step scenario that does a live demonstration of most aspects of GraalVM (modern Java runtime, Ahead of Time compilation to native executable, polyglot runtime platform and the platform […]
Azure Pipelines: publish to Azure Artifacts
This article is a follow-up to my previous article about using Azure Artifacts for own NPM modules. In that article I showed how to create a NPM module by hand on your local system and publish it to Azure Artifacts. But now we like to integrate it into CI/CD, so […]
Using Azure Artifacts for your own NPM modules
Currently I am working on a customer project in which we build a lot of Azure (serverless) functions, mostly in Javascript. Sometime ago we foresaw that we need some shared functionality which was to be used in multiple functions. So wouldn’t it be a good idea to create some shared […]
Spring: Blocking vs non-blocking: R2DBC vs JDBC and WebFlux vs Web MVC
Spring Framework version 5, released in Sept 2017, introduced Spring WebFlux. A fully reactive stack. In Dec 2019 Spring Data R2DBC was released, an incubator to integrate relational databases using a reactive driver. In this blog post I’ll show that at high concurrency, WebFlux and R2DBC perform better. They have […]
The size of Docker images containing OpenJDK 11.0.6
When running Java applications in containers, you need to be careful with your resources. If you’re not careful with layering your images (for example using Google’s Jib), you can quickly get into disk-space issues, especially when your base image and/or application gets updated regularly. One of the ways you can save […]
Override Date.now() based on OS time when Node returns incorrect current date
I was facing a weird issue. In my Node application – version 10.6.3 – running on Ubuntu – 18.04 – I got the wrong value for the current date and time. A call to new Date() and to Date.now() resulted in a wrong value, off by over two months: The […]
Finally, sftp from an Oracle database using plain plsql
Just a quick blog to get me through the Christmas eve. More than 5 years ago I wrote a blog about FTPS from an Oracle databse. In that blog I already mentioned that SFTP using plsql is possible. Not loading some Java classes in the database and adding some plsql […]
Apache Camel + Spring Boot: Different components to expose HTTP endpoints
Apache Camel is an open source integration framework that allows you to integrate technologically diverse systems using a large library of components. A common use-case is to service HTTP based endpoints. Those of course come in several flavors and there is quite a choice in components to use. In this blog post […]
Java Microservices: What do you need to tweak to optimize throughput and response times?
Performance tuning usually goes something like followed: a performance problem occurs an experienced person knows what is probably the cause and suggests a specific change baseline performance is determined, the change is applied, and performance is measured again if the performance has improved compared to the baseline, keep the change, […]
The state of Java [developers] – reflections on Devoxx 2019
![The state of Java [developers] – reflections on Devoxx 2019](https://technology.amis.nl/wp-content/uploads/2019/11/image-4-768x366.png)
I attended Devoxx Belgium – November 2019. The yearly gathering of over 3000 Java developers (numbers provided by Devoxx website). Maybe not all of them Java and perhaps some not even developers. But by and large … Java and software development are the core themes. This conference has taken the […]
Node JS application running on GraalVM – interoperating with Java, Python, R and more
When you install GraalVM, one of the things you get is a Node runtime environment (GraalVM 19.2.1 is based on Node 10.16.3 – with support for the core Node libraries and un understanding of NPM modules – and has a JavaScript engine that is ECAMScript 2019 compliant). Instead of V8, […]
Python application running on GraalVM and Polyglotting with JavaScript, R, Ruby and Java
GraalVM is among other things a polyglot language runtime. It can run applications written in many languages – JVM languages like Java, Scala, Groovy and Kotlin as well as non-JVM language such as Python, R, Ruby, JavaScript and LLVM. GraalVM also allows applications in any of these languages to execute […]
Create a Native Image Binary Executable for a Polyglot Java Application using GraalVM – using build time class initializing
GraalVM provides a runtime component that enhances the JVM in several ways. It makes the JIT compilation better. It also allows the JVM to run non-JVM languages such as JavaScript, R, Python, Ruby and LLVM. And it makes it possible for languages running on the JVM to interact – through […]
Oracle Database: Write arbitrary log messages to the syslog from PL/SQL
Syslog is a standard for message logging, often employed in *NIX environments. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the software type generating the message, and assigned […]
Leverage NPM JavaScript Module from Java application using GraalVM
Interoperability from Java to JavaScript has been an objective for the Java community for quite a while. With GraalVM, there is great way to run JavaScript code from within Java applications. The interaction itself is faster, more robust and more ‘native’ (rather than bolt-on) than earlier mechanisms. For developers, the […]
Calling out from Java to JavaScript (with call back) – leveraging interoperability support of GraalVM
Interoperability from Java to JavaScript has been an objective for the Java community for quite a while. With Rhino and later Nashorn, two valiant attempts were made to add scripting interaction to the JDK and JVM. Now, with GraalVM, there is a better alternative for running JavaScript code from within […]
Calling an Oracle DB stored procedure from Spring Boot using Apache Camel
There are different ways to create data services. The choice for a specific technology to use, depends on several factors inside the organisation which wishes to realize these services. In this blog post I’ll provide a minimal example of how you can use Spring Boot with Apache Camel to call […]
Microservice framework startup time on different JVMs (AOT and JIT)
When developing microservices, a fast startup time is useful. It can for example reduce the amount of time a rolling upgrade of instances takes and reduce build time thus shortening development cycles. When running your code using a ‘serverless’ framework such as for example Knative or FnProject, scaling and getting […]
Apache Camel and Spring Boot: Calling multiple services in parallel and merging results
Sometimes you have multiple services you want to call at the same time and merge their results when they’re all in (or after a timeout). In Enterprise Integration Patterns (EIP) this is a Splitter followed by an Aggregator. I wanted to try and implement this in Spring Boot using Apache Camel so I […]
A transparent Spring Boot REST service to expose Oracle Database logic
Sometimes you have an Oracle database which contains a lot of logic and you want to expose specific logic as REST services. There are a variety of ways to do this. The most obvious one to consider might be Oracle REST Data Services. ORDS is quite powerful and for example supports […]
Graceful shutdown of forked workers in Python and JavaScript running in Docker containers
You might encounter a situation where you want to fork a script during execution. For example if the amount of forks is dependent on user input or another specific situation. I encountered such a situation in which I wanted to put load on a service using multiple concurrent processes. In […]
Performance! 3 reasons to stick to Java 8 for the moment
It is a smart thing to move to newer versions of Java! Support such as security updates and new features are just two of them but there are many more. Performance might be a reason to stick to Java 8 though. In this blog post I’ll show some results of […]
JavaScript Pipelining using Asynchronous Generators to implement Running Aggregates
As of ES 2018 (recent browsers or Node 10), JavaScript support asynchronous generators. Generators are functions that return a set of values, one value at a time. These values can be processed inside the code that invokes the generator immediately, as soon as they become available. There is no need […]
JavaScript Generators – How functions return a stream of results, yielding one result at a time
It was through inspecting some Python code that relied quite heavily that I suddenly realized the beauty of the ES6 concept of generators and the yield keyword. A generator function does not return its result all at once but instead an iterator that can be read from, one value at […]
Building a Conference Session Agenda with Oracle APEX – notes on Pivot, Modal Popup and jQuery
AMIS is part of the Conclusion ecosystem of over 20 companies, each with their own specialty and identity. Several times per year, we organize Conclusion on Stage – a conference that spans across the ecosystem. Presenters from most companies under the Conclusion umbrella submit session proposals. Close to 30 sessions […]