Open Source

Database Modeling Tutorial Using PlantUML

Posted by Alexius Dionysius Diakogiannis on in Architecture, Databases, Open Source 0 Comment

In this tutorial, we’ll explore the database modeling aspect of a small blog using PlantUML. We’ll start by defining the tables and their attributes, then establish relationships between them based on the provided database model.

1. Understanding the Database Model

Let’s review the database model for our small blog:

Tables:

  • Posts: Represents individual blog posts.
  • Users: Stores user information for blog authors.
  • Comments: Contains comments left by users on blog posts.
  • Tags: Stores tags associated with blog posts.
  • PostTags: Join table to establish a many-to-many relationship between posts and tags.

Relationships:

  • Posts – Users: One-to-many relationship where a post belongs to one user.
  • Posts – Comments: One-to-many relationship where a post can have many comments.
  • Posts – Tags: Many-to-many relationship facilitated by the PostTags join table.
  • Tags – Posts: Many-to-many relationship facilitated by the PostTags join table.

Continue reading “Database Modeling Tutorial Using PlantUML” →

Introduction to PlantUML: Unleashing the Power of Visual Representation as a Code in Software Development

Posted by Alexius Dionysius Diakogiannis on in Open Source, Others

Introduction

In the fast-paced world of software development, effective communication and clear documentation are paramount. This is where the power of visual representation comes into play, and one tool that has significantly simplified this process is PlantUML. This open-source project has revolutionized the way developers, project managers, and analysts create and share diagrams. It’s not just a tool; it’s a visual language that transforms the way we think about and document software architecture, processes, and workflows. Continue reading “Introduction to PlantUML: Unleashing the Power of Visual Representation as a Code in Software Development” →

JCrete Unconference: A Convergence of Minds Shaping Java and Beyond

Posted by Alexius Dionysius Diakogiannis on in Conferences

The JCrete 2023 Unconference stands as a premier annual event, taking place in Kolymvari (Chania, Crete) each July since 2010. Renowned for its exclusivity, this invitation-only Unconference brings together influential minds from the computing industry who have significantly impacted the field. The core theme revolves around Java and related subjects, fostering an environment where participants engage in informal discussions to share experiences and collectively learn from one another. Continue reading “JCrete Unconference: A Convergence of Minds Shaping Java and Beyond” →

How to install SonarQube locally or in production to check your code for vulnerabilities, performance and maintainability

Posted by Alexius Dionysius Diakogiannis on in Core Java, Open Source, Security
A picture with a teenager starring. the caption sais looking at your code after one year. Did I wrote that?

Introduction

From Wikipedia: SonarQube (formerly Sonar) is an open-source platform developed by SonarSource for continuous inspection of code quality to perform automatic reviews with static analysis of code to detect bugs and code smells on 29 programming languages. SonarQube offers reports on duplicated code, coding standards, unit tests, code coverage, code complexity, comments, bugs, and security recommendations. SonarQube can record metrics history, evolution graphs and provides fully automated analysis and integration with Maven, Ant, Gradle, MSBuild and continuous integration tools (Atlassian Bamboo, Jenkins, Hudson, etc.). In other words it checks if what your team has written is secure, performs well, it is tested and easy to maintain.

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Dockerizing Java Applications the right way

Posted by Alexius Dionysius Diakogiannis on in Core Java, Docker, Open Source, Spring
alexius diakogiannis dockerizing java applications

I have created a video and I am showing how to place your java application to a docker container BUT in addition I am showing you how to build the application in the container without needing java runtime in the host machine.

Hope you like it

Subscribe to my youtube channel: https://www.youtube.com/channel/UCw_oF0_P645jIECXAlh9Jsw

Use this url to dowload the awesome GitKraken software: https://www.gitkraken.com/invite/pPxN…

Gist: https://gist.github.com/diakogiannis/

Thanks perigialli tavern for giving the space to shoot: https://www.facebook.com/perigiali.estiatorio

Spring Framework 3.2 goes GA

Posted by Alexius Dionysius Diakogiannis on in Frameworks, Open Source, Spring

Ενα χρόνο μετά απο το Spring 3.1 ο Juergen Hoeller ανακοίνωσε την έκδοση 3.2 στο blog της springsource

Κύρια χαρακτηριστηκά είναι

  •  Refined Java SE 7 support
  •  Concurrency refinements across the framework
  •  Allowing for @Autowired and @Value to be used as meta-annotations
  •  Support for custom @Bean definition annotations in @Configuration classes
  •  Asynchronous MVC processing on Servlet 3.0, with Spring MVC handler methods being able to return Callables and DeferredResults
  •  Inclusion of the formerly-standalone Spring MVC Test project, allowing for first-class testing of Spring MVC applications
  •  Support for loading WebApplicationContexts in the TestContext framework, and further improvements for web application testing
  •  Early support for JCache 0.5 (JSR-107) as a backend for Spring’s cache abstraction

Για περισσότερες λεπτομέρειες μπορείτε να δείτε το σχετικό άρθρο της springsource εδώ

SCRIPTED: A JAVASCRIPT EDITOR FROM VMWARE

Posted by Alexius Dionysius Diakogiannis on in Open Source

The first version of the Scripted code editor has been released this week on github: https://github.com/scripted-editor/scripted.

Although Scripted is a general purpose code editor, the initial focus is building a great JavaScript editing experience. Scripted itself is built entirely in JavaScript and HTML/CSS. It is a browser-based editor that runs locally on a developer’s machine with a Node.js instance being used to serve the editor code and perform the editor operations. The only pre-req for running Scripted is that you have a recent version of Node.js installed (we are testing with Node 0.8.11 right now). Scripted reuses the editor component from Eclipse Orion.

Ream More on SPRINGSOURCE BLOG

 

Εγκατάσταση Apache Directory Server (ApacheDS) σε UBUNTU

Posted by Alexius Dionysius Diakogiannis on in Linux, Open Source, Security, Spring

Ο ApacheSD είναι μια ανερχόμενη δύναμη στους Directory Servers, είναι Java based και χρησημοποιεί το γνωστό framework Spring για την λειτουργεία του.

Η Εγκαταστασή του στο Ubuntu είναι αρκετά εύκολή υπόθεση.

Προαπαιτούμενα

Πρέπει να υπάρχει στο σύστημα Java έκδοση 5 ή μεγαλύτερη. Προτείνω την SUN-JAVA και ότι το OpenJDK

Για να το ελενξουμε αυτό δίνουμε

[bash]
java -version
[/bash]

και περιμένουμε να δούμε κάτι παρόμοιο με το παρακάτω

[text]
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)
[/text]

Αν λοιπον δεν είναι εγκατεστημένη τότε δίνουμε το παρακάτω στην κονσόλα

[bash]
sudo apt-get -y install maven2 sun-java6-jdk java-common
[/bash]
Continue reading “Εγκατάσταση Apache Directory Server (ApacheDS) σε UBUNTU” →