mvn package jar of Kotlin

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Error

fat jar

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Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/jvm/internal/Intrinsics
        at com.fintend.accounting.ApplicationKt.main(Application.kt)
Caused by: java.lang.ClassNotFoundException: kotlin.jvm.internal.Intrinsics
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 1 more

Experienced Java developers will quickly recognize this type of exception. By default when Gradle (as well as Maven) packs some Java class files into a JAR file, it is assumed that this JAR file will be referenced by an application, where all of its dependencies are also accessible within the classpath of the loading application.

To execute a JAR without having to specifiy the path to itse dependencies, one must tell the build system to take all of this JAR’s referenced dependencies and copy them as part of the JAR itself. In the Java community, this is known as a “fat JAR”. In a “fat JAR” all of the dependencies end up within the class path of the loading application, so code can be executed without problems.

The only downside to creating fat JARs is of course their growing file size (which kind of explains the name), though in most situations, it is not a big concern. In order to tell Gradle to copy all of a JAR’s dependencies, one should simply modify the abovementioned JAR task configuration, by adding the following piece of code:

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<?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.xxx</groupId>
    <artifactId>xxx</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <kotlin.version>1.2.70</kotlin.version>
        <kotlin.compiler.incremental>true</kotlin.compiler.incremental>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib-jdk8</artifactId>
            <version>${kotlin.version}</version>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test-junit</artifactId>
            <version>${kotlin.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-reflect</artifactId>
            <version>${kotlin.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-kotlin</artifactId>
            <version>2.9.6</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.6</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>25.1-jre</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
            <version>2.6.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>
        <testSourceDirectory>${project.basedir}/src/test/java</testSourceDirectory>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
        <testResources>
            <testResource>
                <directory>src/test/resources</directory>
                <filtering>true</filtering>
            </testResource>
        </testResources>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                        <configuration>
                            <archive>
                                <manifest>
                                    <mainClass>xx.xxx.xxx.ApplicationKt</mainClass>
                                </manifest>
                            </archive>
                            <descriptorRefs>
                                <descriptorRef>jar-with-dependencies</descriptorRef>
                            </descriptorRefs>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.jetbrains.kotlin</groupId>
                <artifactId>kotlin-maven-plugin</artifactId>
                <version>${kotlin.version}</version>
                <configuration>
                    <args>
                        <arg>-Xcoroutines=enable</arg>
                    </args>
                </configuration>
                <executions>
                    <execution>
                        <id>compile</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>test-compile</id>
                        <phase>test-compile</phase>
                        <goals>
                            <goal>test-compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.liquibase</groupId>
                <artifactId>liquibase-maven-plugin</artifactId>
                <version>3.6.2</version>
                <configuration>
                    <propertyFile>${basedir}/src/main/resources/liquibase/liquibase.properties</propertyFile>
                </configuration>
                <executions>
                    <execution>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>update</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>