Maven Build Plugin doesn't include my own classes

Question

I have the following (very) simple pom.xml:

<?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>ro.ace.ucv</groupId>
    <artifactId>message_generator</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <scala.major.version>2.10</scala.major.version>
        <scala.version>${scala.major.version}.5</scala.version>
        <spark.version>1.6.0</spark.version>
        <spark.streaming.version>1.6.0</spark.streaming.version>
        <spark.sql.version>1.6.0</spark.sql.version>
        <spark.version>1.6.0</spark.version>
        <junit.version>4.12</junit.version>
        <scalatest.version>2.1.3</scalatest.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka_2.11</artifactId>
            <version>0.10.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.avro</groupId>
            <artifactId>avro</artifactId>
            <version>1.8.1</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>com.message.generator.MessageGeneratorMain</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

and the following (very) simple project structure:

\\message_generator\\src\\main\\scala\\com\\message\\generator\\MessageGeneratorMain.scala

When running mvn clean compile assembly:single

I get a jar with dependencies, but my own code (3 classes, including the Main one) is not included in the final jar.

Answer 1

You must include the Maven Scala plugin to catch the scala code in src/main/scala

<build>
    <plugins>
        <plugin>
            <groupId>org.scala-tools</groupId>
           <artifactId>maven-scala-plugin</artifactId>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>