The error java.lang.OutOfMemoryError:Metaspace indicates that you have exhausted an area of JVM which serves as a registry for your application’s Class Metadata. This article is a step-by-step guide to fix Java Metaspace errors with Java 17’s elastic metaspace (JEP 387), diagnostic tools like jcmd, and best practices for JVM configuration.
F.Marchioni
Solving Unable to load the mojo ‘war’ in the plugin
If you’re migrating a Java EE or Jakarta EE project to Java 17 or later, and you’re using Maven 3.8 or newer, you might encounter the following error during a mvn package or mvn install: ” Unable to load the mojo ‘war’ in the plugin ‘org.apache.maven.plugins:maven-war-plugin‘. This issue is often triggered when your project implicitly uses an outdated version of the maven-war-plugin that is incompatible with newer Java versions or Maven APIs.
How to configure beans.xml in CDI applications
The beans.xml file is the bean archive descriptor for CDI applications. It can be used for any CDI compliant container, such as Weld which is included in WildFly application server.
How to run WildFly as Service
The guide discusses how to configure WildFly or JBoss as a Service on a Linux machine or on a Windows box. We will cover the code settings and addresses common pitfalls and aligns with current best practices. Linux (systemd Integration) WildFly 36 includes native systemd support. Follow these steps: Firstly, generate Systemd Files: Then, replace … Read more
How to Start, Stop and Restart JBoss or WildFly
This guide contains some tips to teach you how to start, stop, restart WildFly application server. By the end of this tutorial, you will be able to effectively manage the lifecycle of your Wildfly server as needed. Besides, we provide some troubleshooting tips to verify why the start or restart does not work.
JUnit Testing Best Practices: Verifying No Exceptions in Your Java Code
Introduction When writing tests in Java, it’s important to verify that a method or code block behaves as expected. One of the most common things to check is whether an exception is thrown during the execution of a test. However, sometimes we also want to verify that no exception is thrown. This can be particularly … Read more
PrimeFaces with Jakarta EE 10 made simple
In this updated article we will discuss how to create and deploy a Jakarta EE 11 ( available since June 2025) application that uses Primefaces as Jakarta Faces implementation. We will build a sample application that will run in microservice-style as WildFly Bootable JAR.
Choosing the right JDK for WildFly and JBoss EAP
This tutorial discusses the recommended JDK versions to be used for WildFly and JBoss Enterprise Application Platform (EAP) and how to set the Java version for it. The article is updated to July 2025 and we will keep it in sync with new server versions as thei are available.
How to migrate WildFly version with JBoss Migration tool
Upgrading a WildFly or JBoss EAP manually can be error-prone and time-consuming. Fortunately, the JBoss Server Migration Tool helps automate this process by transferring relevant configuration and deployments from one WildFly version to another.
How to validate Database connections in JBoss / WildFly
This tutorial discusses how to validate Datasource connections using in WildFly using proper validation methods. Besides, it will discuss how to troubleshoot database connections which are not properly replaced when Database connections are no longer valid. Connection Validation in a nutshell A datasource connection validation helps to ensure that the connections to the database are … Read more