Java Angular DevOps | Marco Molteni

Spring Annotations: The 2026 Essential Cheat Sheet

Master Spring annotations in 2026: from core stereotypes to new features like native resilience, virtual threads support, and null safety. / 2026-01-22

Lombok: The Batman of the JRE that saved Java from Boilerplate

Is Lombok a bad citizen or a Superhero? / 2026-01-21

Why WordPress bots keep knocking on your Java server

Stop wasting JVM threads on WordPress bots. Here is how to block PHP scanners at the Cloudflare, Nginx, and Spring Security levels to keep your Java logs clean. / 2026-01-21

How to Fix “Port 8080 Already in Use” in Spring Boot (Mac, Linux, Windows)

Learn how to fix the “Port 8080 already in use” error in Spring Boot. Find and kill the process on Mac, Linux, or Windows and prevent future port conflicts. / 2026-01-16

The Friction Zone: Why mixing Kotlin, Java, Hibernate and Lombok is a technical debt nightmare

Transitioning a legacy Java monolith to Kotlin sounds like a modern developer’s dream, but when that project relies on Hibernate and Lombok, the "100% interoperability" promise quickly unravels. This post explores the deep-rooted architectural conflicts that occur when Kotlin’s opinionated, null-safe design meets the "anything-goes" reflection-heavy world of JPA. / 2026-01-16

Lombok - Java JDK compatibility matrix

Lombok and JDK compatibility / 2025-10-05

Spring Boot best practices and Spring pitfalls

Some tips to improve your Spring development / 2025-06-21

Spring Boot: Interfaces or CGLIB?

Learn the trade-offs between using interfaces and CGLIB for AOP proxying in Spring Boot applications. / 2025-06-21

Spring Boot Multipart Upload: Combining JSON Data and File in One Request

How to handle mixed http requests in Spring / 2025-04-09

Migration from Kotlin to Java, notes

Steps for the migration from Kotlin to Java, notes / 2025-03-27

Learn Java in 15 minutes ... and call us to repair the damages for 12 months :)

The origin of the technical debt / 2025-02-15

Send an image from the Java backend to Angular or React using REST services

/ 2025-02-12

Enum Literals in Hibernate and JPA: A Surprisingly Astonishing Difference

Code review lessons. A simple question about a query challenged the online solutions. / 2025-02-02

Spring Boot vs Quarkus in 2025

Is Quarkus relevant in 2025? / 2025-02-01

Lombok and Java 23 compilation issues

Java 23 Lombok compilation error, how to fix it. / 2024-11-23

Apache NetBeans - clear the cache and rebuild maven indexes

Sometimes a cleanup can fix IDE issues / 2024-08-24

JPA FetchType.Eager is NOT a solution for n+1 queries issue

How to avoid n+1 queries between your entities / 2024-08-20

Spring Boot and Hibernate, measure the performances

How to configure hibernate to show execution performances / 2024-05-06

What are Java Patterns

What are Java patterns / 2024-04-04

Java 22 notes

What is coming with the new Java release / 2024-04-03

Azure Storage Java tutorial

Learn how to easily integrate Azure Blob Storage into your Java application to store and retrieve markdown blog posts. A step-by-step guide. / 2024-04-01

Connect to MinIO using Java

Use MinIO as alternative to AWS S3 and Azure Storage / 2024-04-01

JPA, Spring and Kotlin: store a list or an array in a column of the database

How to use arrays in JPA using Kotlin / 2024-03-26

GitLab: build and distribute your Java application using a Docker image

Java CI/CD pipeline with Gitlab / 2024-01-10

Java and Docker: setup parameters for speed and memory

Size your JVM for docker to avoid surprises / 2024-01-09

How to deploy a Java and React webapp in one JAR/WAR

How to configure a fullstack React and Spring Boot application / 2024-01-08

How to use PostgreSQL with WildFly and JBoss

Tutorial: Configuring PostgreSQL in WildFly and JBoss / 2024-01-05

Maven: How to skip tests in Java

Unit Tests - When Your Ex-Colleagues Haunt You Through Code / 2024-01-05

How to deploy a Java and Angular webapp in one JAR/WAR

How to configure a fullstack Angular and Spring Boot application / 2023-12-28

Spring Boot OpenAPI generator example

How to generate your REST methods and Spring controllers using OpenAPI / Swagger / 2023-12-28

Deploy Angular with Spring Boot in the same executable JAR

Tutorial: How to build an Angular 15 and Spring Boot 3 app in a single JAR. Maven configuration. / 2023-12-28

How to deploy a Spring Boot application with Docker and Java 21

Simple deploy of your Spring Boot app and check health with Docker Compose / 2023-12-19

How to force or override the version of a dependency in Maven

Override the version of a third party library in Maven / 2023-12-15

HttpClient: Example and improvements in Java 21

Java HttpClient example / 2023-12-11

Force the use JAXB with Spring Boot

How to force Spring Boot to use JAXB and not Jackson / 2023-12-07

Project checklists

/ 2023-12-06

Node and Angular install and update

/ 2023-12-06

Spring Boot tests: How to override the properties in your test class

How to define specific properties for a Spring Boot test class / 2023-11-21

RestControllerAdvice: how to handle exceptions in Spring Boot

Organise and tests the exceptions using ControllerAdvice / 2023-11-16

Building a Java Angular application tutorial and best practices

Step-by-step guide to building a full-stack Java and Angular application. Covers setup, deployment, error handling, and best practices for a production-ready app. / 2023-11-01

Spring Boot 3.1.2: This method cannot decide ... error

Causes and solutions for the Spring Boot 3.1.2 error: This method cannot decide whether these patterns are Spring MVC patterns or not. / 2023-08-14

Spring: Autoconfiguration package and the missing JPA Entities (Not a managed type error)

Configure Spring Boot a multi module project with JPA entities in a different module. / 2023-04-23

@PostConstruct and @PreDestroy examples in Java

How execute code when your Spring Boot application starts / end / 2023-04-07

Deploy a Java Web App in DigitalOcean using GitHub Actions

How to deploy a maven application in DigitalOcean directly from GitHub / 2023-04-06

Spring Boot Liquibase Tutorial

Tutorial: use Liquibase with Spring to update your database / 2023-03-27

How to use Oracle and PostgreSQL scripts and functions in H2 Database using Java

/ 2022-10-10

Spring Boot update the HTTP Headers of the static assets

/ 2022-10-06

How to remember original Design patterns during a technical interview

Can each team member be linked to a Design Pattern? / 2022-03-15

Spring Boot Kafka example

Learn how to integrate Spring Boot with Kafka using Docker Compose. Includes code for producers, consumers, and error handling. / 2022-02-28

Spring Boot: REST controller Test example

How to test the @RestController with Spring Boot / 2022-02-14

Spring Boot RestTemplate: test GET request with JSON body is not working

How to test your REST GET controller with Spring Boot / 2022-02-11

Java 18 new features - Simple Web Server

A basic web server for testing and education / 2022-02-02

Java Streams and Lambda quick introduction

Quick notes about Java Streams and Lambda expressions / 2022-01-27

How to return a custom 404 or 410 with Spring Boot

How to create a custom error page in Spring Boot and fix the Whitelabel error page / 2022-01-14

How to reverse a String in Java

How to reverse a String in Java, for the interview and the fun / 2022-01-11

Spring Boot error message: Failed to configure a DataSource

Why the DataSource error appears and how to solve it / 2022-01-05

Generate a sitemap with Java

Generate a sitemap with Java for your Website. / 2022-01-04

Java 17: Map.Entry.copyOf

A new function introduced in Java 17 / 2022-01-04

Spring Boot and MongoDB example

How to connect Spring Boot to MongoDB / 2022-01-04

Eclipse setup for Java Development

First steps after installing Eclipse / 2022-01-01

Log4j - How to protect my application?

Is my application vulnerable? Which version should I use? Is Spring Boot impacted? / 2021-12-16

How to hot deploy a Spring Boot application

Hot deployment with Spring Boot? It is possible! / 2021-12-06

How to convert an array of bytes to a String in Java

How to convert byte[] to String and vice versa / 2021-11-30

Maven: install on mac. Tutorial for brew and the official method.

How to install Maven on mac using brew, tutorial using macOS Monterey - M1 / 2021-11-24

Spring Boot: How do I execute my code on startup?

Spring Boot: How do I execute my code on startup? / 2021-11-24

Spring: test your MySQL JPA with H2

How to test your repository using H2 when you use MySQL in production. / 2021-03-21

Fix the Whitelabel error in Angular and Spring Boot

How to solve the Whitelabel Error when a Javascript (React, Angular) application is deployed with Spring Boot / 2021-03-05

Add Grafana to your Spring / Quarkus application using Jelastic

Tutorial: add Grafana and Prometheus to a Spring Boot / Quarkus app using Jelastic / 2021-02-14

MariaDB root password error

How to solve the error 1064 (42000) when you install MariaDB / 2021-01-21

MariaDB root password error

Solve the Access Denied for User root@localhost error / 2021-01-21

Spring Boot redirect and HTTP 301

Migration from Jekyll to Spring Boot / 2021-01-21

Spring Boot MariaDB connection and issues

How to connect Spring Boot to MariaDB / 2021-01-21

Java sealed classes

Sealed classes - Java 17 LTS new feature / 2020-10-29

Java Text Blocks

Text blocks - Migrating from Java 11 LTS to Java 17 LTS - Java 15 new feature / 2020-10-29

Java 15

Java 15 new features / 2020-10-27

Java test preview features

Java test preview features / 2020-10-27

Maven: find a package

Search a dependency in a maven tree / 2020-07-15

Java Records, tutorial and code examples

Records in Java 14. Published in DZone. / 2020-01-23

How to preview the new features in Java

How to use preview features in Java / 2020-01-23

Artificial Intelligence for Java: resources

AI and ML resources for Java developers / 2019-11-24

Java 14 new features

Whats new in Java 14 / 2019-11-19

Angular and Java Setup on Mac

Quick and easy install Java and Angular / 2019-11-17

Garbage collectors for the busy Java developer (10 min, no maths ;))

(Video + Slides) JavaZone Conference / 2019-10-01

Java 17 new feature: Teeing Collector

Teeing Collector examples. A Java 17 LTS new feature! / 2019-03-23

Calculate the difference between two dates in Java

Count the days between two dates / 2019-02-11

The final keyword in Java

The final keyword doesnt guarantee the immutabily of your objects. Its really performant? / 2019-02-03

Initialize a HashMap in Java - Best practices

HashMap initialization and best practices / 2019-01-10

Configure nginx in Jelastic

Use compression with nginx / 2019-01-05

Difference between protected and default/package access in Java

Visual memo of the access modifiers and controls / 2019-01-05

Create a list of objects from a file using lambda expressions in Java

Read the file, create and sort the object list / 2019-01-04

Config files in Java EE / Jakarta EE using MicroProfile

How to store the configuration in external files? / 2018-11-14

Blockchain: How to generate a SHA-256 hash with Java

Blockchain: How to generate a SHA-256 hash with Java / 2018-10-25

Whats new in Java 11

Here some of the new features of Java 11 with a direct impact on the daily development activity. / 2018-09-15

Spring Integration mail

How to send email using Spring Integration and create smtp unit tests / 2018-08-11

Comment déployer une application web en Java et Angular dans un seul artéfact JAR ou WAR

‘Comment configurer une application Angular et Spring Boot Full-Stack’ / 2018-04-26

Spring Boot, Caching and Hazelcast

How to add caching features with Hazelcast / 2017-11-20

Build, test and deploy with Jenkins

One click deploy your Java application (Java EE, Spring) / 2017-09-17

Create Cross-Origin requests (CORS)

How to allow communication between your Angular frontend and the Java Backend / 2017-07-13

REST and Spring Boot: manage users rights with a custom Filter and properties

Simple solution when only few users have writing rights. / 2017-07-08

Java EE 8 - CDI 2.0: Events and Observers

Java EE 8 - CDI 2.0: Events and Observers / 2017-04-19

Why when I refresh a page in Angular with Java I get an http 404 error?

/ 2017-04-12

Tutorial : Deploy your Java app with AWS Elastic Beanstalk - Tutorial

/ 2017-03-01

Performance improvement with Angular and Spring Boot

/ 2017-02-20

H2 with Spring Boot and JPA - Tutorial

/ 2017-02-02

Cheap and easy DevOps for developers (Docker, Ubuntu, Apache and Spring)

/ 2017-01-30

How to test our REST services using Spring Boot?

/ 2017-01-29

Angular, Spring Boot and OAuth2

/ 2017-01-19

Scrum and Java projects. Why they tend to fail?

/ 2016-10-11

Understanding JVM Threads in a Hello World Java Application

/ 2016-04-21

Change JDK and JRE in Eclipse for Mac OS

/ 2016-04-20

Java Server Sent Event - Automatically update web pages

/ 2016-04-17