Create a new Maven Java application project using the maven archetype:

$ mvn archetype:generate \
  -DarchetypeGroupId=org.apache.maven.archetypes \
  -DarchetypeArtifactId=maven-archetype-quickstart \
  -DarchetypeVersion=1.5 \
  -DgroupId=mtitek.maven.jar.samples \
  -DartifactId=mtitek-maven-jar-samples \
  -Dpackage=mtitek.maven.jar.samples \
  -Dversion=1.0.0-SNAPSHOT \
  -DinteractiveMode=false

The generated project structure will look like this:

$ find ./mtitek-maven-jar-samples/ -type f
./mtitek-maven-jar-samples/pom.xml
./mtitek-maven-jar-samples/src/main/java/mtitek/maven/jar/samples/App.java
./mtitek-maven-jar-samples/src/test/java/mtitek/maven/jar/samples/AppTest.java

The archetype creates a minimal structure. Typically the project structure should look like:

mtitek-maven-jar-samples/
├── pom.xml
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── mtitek/
│   │   │       └── maven/
│   │   │           └── jar/
│   │   │               └── samples/
│   │   │                   ├── App.java
│   │   │                   └── SomeClass.java
│   │   ├── resources/
│   │   │   └── application.properties
│   │   └── test/
│   │       └── java/
│   │           └── mtitek/
│   │               └── maven/
│   │                   └── jar/
│   │                       └── samples/
│   │                           └── AppTest.java
└── target/
    └── mtitek-maven-jar-samples-1.0.0-SNAPSHOT.jar

Once the project is generated, you should update the pom.xml file. Here's an example:

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>mtitek.maven.jar.samples</groupId>
    <artifactId>mtitek-maven-jar-samples</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <!-- Spring Boot property -->
        <java.version>23</java.version>

        <!-- maven-compiler-plugin properties -->
        <maven.compiler.source>23</maven.compiler.source>
        <maven.compiler.target>23</maven.compiler.target>
        <maven.compiler.release>23</maven.compiler.release>

        <!-- format of maven.build.timestamp environment variable -->
        <maven.build.timestamp.format>yyyy-MM-dd HH:mm:ss</maven.build.timestamp.format>

        <!-- Plugin versions -->
        <maven-compiler-plugin.version>3.14.0</maven-compiler-plugin.version>
        <maven-jar-plugin.version>3.4.2</maven-jar-plugin.version>
        <maven-surefire-plugin.version>3.5.3</maven-surefire-plugin.version>
        <junit.version>5.13.1</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>

                <configuration>
                    <encoding>UTF-8</encoding>

                    <!-- optional if maven.compiler.source property is set -->
                    <source>${maven.compiler.source}</source>
                    <!-- optional if maven.compiler.target property is set -->
                    <target>${maven.compiler.target}</target>
                </configuration>
            </plugin>

            <!-- Surefire plugin for JUnit 5 support -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>${maven-surefire-plugin.version}</version>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>${maven-jar-plugin.version}</version>

                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <mainClass>mtitek.maven.jar.samples.App</mainClass>
                            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                        </manifest>

                        <manifestEntries>
                            <Implementation-Build>${maven.build.timestamp}</Implementation-Build>

                            <Implementation-Title>mtitek maven jar samples</Implementation-Title>
                            <Implementation-Version>${project.version}</Implementation-Version>
                            <Implementation-Vendor-Id>mtitek</Implementation-Vendor-Id>
                            <Implementation-URL>http://www.mtitek.com</Implementation-URL>

                            <custom-manifest-entry>mtitek</custom-manifest-entry>
                        </manifestEntries>
                    </archive>
                </configuration>

                <executions>
                    <execution>
                        <id>default-jar</id>
                        <phase>package</phase>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>

                    <execution>
                        <id>test-jar</id>
                        <phase>package</phase>
                        <goals>
                            <goal>test-jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Build the project:

$ mvn clean install

Use the command "java -jar" to test your jar:

$ java -jar target/mtitek-maven-jar-samples-1.0.0-SNAPSHOT.jar

Hello World!