fix: Pom and Docker for Java 21

Recent update of Java 21 broke the Dockerfile. The pom.xml file is also
broken. Fixing it 🤘

Dockerfile

@@ -1,5 +1,5 @@
 # Step 1: Use an official Maven image to build the project
-FROM docker.io/maven:3.8.8-eclipse-temurin-17 AS build
+FROM docker.io/maven:3.9.9-eclipse-temurin-21 AS build
 
 # Step 2: Set the working directory inside the container
 WORKDIR /app
@@ -11,7 +11,7 @@ COPY . .
 RUN mvn clean package
 
 # Step 5: Use Tomcat image to deploy the WAR
-FROM docker.io/tomcat:jdk17
+FROM docker.io/tomcat:jdk21
 
 # Step 6: Set the working directory inside the Tomcat container
 WORKDIR /usr/local/tomcat/webapps

README.md

@@ -47,45 +47,36 @@ The `HelloWorldMainLauncherClass` performs the following tasks:
 
 ## Prerequisites
 
-- Java Development Kit (JDK) 8 or higher.
+- Java Development Kit (JDK) 21 or higher.
 - A Java IDE (like IntelliJ IDEA, Eclipse, or NetBeans) or a command-line environment to compile and run the Java program.
 
 ## Installation
 
 To set up and run this project locally, follow these steps:
 
 1. Clone the repository:
+
    ```bash
    git clone https://github.com/NanowarOfSteel/HelloWorld.git
    ```
 
 2. Navigate into the project sources directory:
-   ```bash
-   cd HelloWorld/src/main/java
-   ```
-
-3. Compile the Java file:
-   ```bash
-   javac it/nanowar/ofsteel/helloworld/HelloWorldMainLauncherClass.java
-   ```
 
-4. Run the program:
    ```bash
-   javac it/nanowar/ofsteel/helloworld/HelloWorldMainLauncherClass.java
+   cd HelloWorld
    ```
 
-Alternatively, with Java 11 you can compile and run the project in one single step:
-
 3. Compile and run the Java file:
+
    ```bash
-   java it/nanowar/ofsteel/helloworld/HelloWorldMainLauncherClass.java
+   java src/main/java/it/nanowar/ofsteel/helloworld/HelloWorldMainLauncherClass.java
    ```
 
 ## Usage
 
 Once you run the program, you will see the following output:
 
-```
+```text
 Hello World Programmer Start
 Hello World!
 Hello World!
@@ -211,13 +202,14 @@ in the root directory of the project, then point out the location of the
 Dockerfile with the `-f` option:
 
 ```bash
-docker build -t my-java-app -f src/main/docker/helloworld.dockerfile .
+docker build -t my-java-app .
 ```
 
 This command will:
+
 1. Use an official Maven image to build the application.
 2. Package the application into a JAR file.
-3. Use a slim OpenJDK 17 image to run the resulting application (**kinda**).
+3. Use a slim OpenJDK 21 image to run the resulting application (**kinda**).
 
 ## Usage
 

pom.xml

@@ -4,8 +4,8 @@
   <artifactId>HelloWorld</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <properties>
-     <maven.compiler.source>17</maven.compiler.source>
-     <maven.compiler.target>17</maven.compiler.target>
+    <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
 </properties>
 <build>
   <plugins>
@@ -24,14 +24,17 @@
         </archive>
       </configuration>
     </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-war-plugin</artifactId>
+        <version>3.4.0</version>
+        <configuration>
+          <warName>nano</warName>
+        </configuration>
+      </plugin>
   </plugins>
 </build>
   <packaging>war</packaging>
-  <properties>
-    <maven.compiler.source>21</maven.compiler.source>
-    <maven.compiler.target>21</maven.compiler.target>
-  </properties>
-
   <dependencies>
     <dependency>
       <groupId>jakarta.servlet</groupId>
@@ -52,17 +55,4 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
-
-    <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-war-plugin</artifactId>
-        <version>3.4.0</version>
-        <configuration>
-          <warName>nano</warName>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
 </project>