MigLayout ClassNotFoundException when creating maven jar

Question

I'm trying to create a jar file of my simple java gui application. I'm using Intellij IDEA and maven. I have imported Mig Layout as a maven dependency, when I run the program inside Intellij IDEA everything works fine, but when I create a jar by doing mvn clean install or mvn clean package, although maven says BUILD SUCCESSFUL, when I try to open the jar file I get the following Stacktrace (I believe it's a stack trace). The image Stacktrace Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: net/miginfocom/swing/MigLayout at BotGui.<init>(BotGui.java:29) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$500(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) Caused by: java.lang.ClassNotFoundException: net.miginfocom.swing.MigLayout at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 15 more

this is my dependencies in maven.

<?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>com.ptcontact.testdiscord</groupId>
    <artifactId>Discord_Bot</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>com.miglayout</groupId>
            <artifactId>miglayout-swing</artifactId>
            <version>5.0</version>
        </dependency>

        <dependency>
            <groupId>net.dv8tion</groupId>
            <artifactId>JDA</artifactId>
            <version>3.8.0_436</version>
        </dependency>
    </dependencies>

    <repositories>
        <repository>
            <id>jcenter</id>
            <name>jcenter-bintray</name>
            <url>https://jcenter.bintray.com</url>
        </repository>
    </repositories>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <target>8</target>
                    <source>8</source>
                </configuration>
            </plugin>
            <plugin>
                <!-- Build an executable JAR -->
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <classpathPrefix>lib/</classpathPrefix>
                            <mainClass>BotGui</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-site-plugin</artifactId>
                <version>3.7.1</version>
            </plugin>
        </plugins>
    </build>

</project>

Yes I have tried out version 5.0, 4.2 and 5.2. Additionally, I have tried to add miglayout-core as a dependency as well, but that didn't change anything.

Answer 1

I Resolved the problem! Like @CrazyCoder said, I needed to create a Fat Jar, in other words I needed to actually include the dependencies inside my jar file. Because I'm a beginner I thought that maven did that for you automatically, oh well.

To create a fat jar, I followed this guide: http://tutorials.jenkov.com/maven/maven-build-fat-jar.html