[JAVA] .jar Datei erstellen?

import com.github.twitch4j.TwitchClient;
import com.github.twitch4j.TwitchClientBuilder;
import org.bukkit.Bukkit;
import org.bukkit.plugin.java.JavaPlugin;

public final class FollowerEvents extends JavaPlugin {

    @Override
    public void onEnable() {
        Bukkit.getServer().broadcastMessage("Geladen!");
        try{
            TwitchClient twitchClient = TwitchClientBuilder.builder()
                    .withEnableHelix(true)
                    .build();
            twitchClient.getClientHelper().enableFollowEventListener("classybeef");
            FollowNotification followNotification = new FollowNotification(twitchClient.getEventManager());
        }
        catch(ExceptionInInitializerError e){
            System.out.println(e);
        }

    }

    @Override
    public void onDisable() {
        // Plugin shutdown logic
    }
}

import com.github.philippheuer.events4j.EventManager;
import com.github.twitch4j.chat.events.channel.FollowEvent;
import org.bukkit.Bukkit;
import reactor.core.Disposable;

import java.util.function.Consumer;

public class FollowNotification {

    public FollowNotification(EventManager eventManager) {
        final Disposable subscribe = eventManager.onEvent(FollowEvent.class).subscribe(new Consumer<FollowEvent>() {
            public void accept(FollowEvent event) {
                FollowNotification.this.onFollow(event);
            }
        });
    }

    public void onFollow(FollowEvent event){
        String followerName = event.getUser().getName();
        Bukkit.getServer().broadcastMessage(followerName + " folgt jetzt!");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<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>JulianAlker</groupId>
    <artifactId>FollowerEvents</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>FollowerEvents</name>

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

    <build>
        <defaultGoal>clean package</defaultGoal>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.0</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <minimizeJar>true</minimizeJar>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>fully.qualified.MainClass</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

    <repositories>
        <repository>
            <id>spigotmc-repo</id>
            <url>https://hub.spigotmc.org/nexus/content/groups/public/</url>
        </repository>
        <repository>
            <id>jcenter</id>
            <url>https://jcenter.bintray.com/</url>
        </repository>
        <repository>
            <id>jcenter-snapshot</id>
            <url>https://oss.jfrog.org/artifactory/libs-release/</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.bukkit</groupId>
            <artifactId>bukkit</artifactId>
            <version>1.14.4-R0.1-SNAPSHOT</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.github.twitch4j</groupId>
            <artifactId>twitch4j</artifactId>
            <version>1.0.0-alpha.17</version>
        </dependency>
    </dependencies>
</project>