Can't run Scala jar from command line

Question

I'm trying to run my Scala jar (built with Maven) from the command line, nut getting this error:

java.lang.ClassNotFoundException: my.jar.App
        at scala.reflect.internal.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:63)
        at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:101)
        at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:22)
        at scala.tools.nsc.JarRunner$.run(MainGenericRunner.scala:13)
        at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:29)
        at scala.tools.nsc.JarRunner$.runJar(MainGenericRunner.scala:25)
        at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:69)
        at scala.tools.nsc.MainGenericRunner.run$1(MainGenericRunner.scala:87)
        at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:98)
        at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:103)
        at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

I have specified in the POM file:

<properties>
    <app.main.class>my.jar.App</app.main.class>
</properties>

And using the plugin from this answer.

Any ideas why this happens?

EDIT:

My pom.xml:

<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>myJars</groupId>
  <artifactId>jar_${scala.binary.version}</artifactId>
  <version>1.1.0</version>
  <packaging>jar</packaging>

  <name>My Jar ${scala.binary.version}</name>

  <properties>
    <app.main.class>my.jar.App</app.main.class>
    <spark.version>1.6.1</spark.version>
    <scala.version>2.10.4</scala.version>
    <scala.binary.version>2.10</scala.binary.version>
  </properties>

  <pluginRepositories>
    <pluginRepository>
      <id>scala-tools.org</id>
      <name>Scala-tools Maven2 Repository</name>
      <url>http://scala-tools.org/repo-releases</url>
    </pluginRepository>
  </pluginRepositories>

  <repositories>
    <repository>
      <id>maven-repo</id>
      <name>Maven Repository</name>
      <url>http://repo1.maven.apache.org/maven2</url>
      <releases>
        <enabled>true</enabled>
      </releases>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
    <repository>
      <id>apache-repo</id>
      <name>Apache release repo</name>
      <url>https://github.com/adatao/mvnrepos/tree/master/releases/</url>
    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <groupId>org.scalaj</groupId>
      <artifactId>scalaj-http_${scala.binary.version}</artifactId>
      <version>1.1.5</version>
    </dependency>

    <dependency>
      <groupId>org.scala-lang</groupId>
      <artifactId>scala-library</artifactId>
      <version>${scala.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.scalatest</groupId>
      <artifactId>scalatest_${scala.binary.version}</artifactId>
      <version>2.2.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>net.liftweb</groupId>
      <artifactId>lift-json_2.10</artifactId>
      <version>3.0-M1</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.5</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.5</version>
    </dependency>
    <dependency>
      <groupId>com.timgroup</groupId>
      <artifactId>java-statsd-client</artifactId>
      <version>3.0.1</version>
    </dependency>

  </dependencies>

  <build>
    <extensions>
      <extension>
        <groupId>org.springframework.build</groupId>
        <artifactId>aws-maven</artifactId>
        <version>5.0.0.RELEASE</version>
      </extension>
    </extensions>
    <sourceDirectory>src/main/scala</sourceDirectory>
    <testSourceDirectory>src/test/scala</testSourceDirectory>
    <pluginManagement>
      <plugins>
 <plugin>
  <!-- Build an executable JAR -->
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-jar-plugin</artifactId>
  <version>2.4</version>
  <configuration>
    <archive>
      <manifest>
        <addClasspath>true</addClasspath>
        <classpathPrefix>lib/</classpathPrefix>
        <mainClass>${app.main.class}</mainClass>
      </manifest>
    </archive>
  </configuration>
</plugin>
        <plugin>
          <groupId>org.scala-tools</groupId>
          <artifactId>maven-scala-plugin</artifactId>
          <version>2.15.2</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.1</version>
          <configuration>
            <source>1.7</source>
            <target>1.7</target>
          </configuration>
        </plugin>
        <plugin>
          <groupId>org.apache.felix</groupId>
          <artifactId>maven-bundle-plugin</artifactId>
          <version>2.3.7</version>
          <extensions>true</extensions>
          <configuration>
            <archive>
              <manifest>
                <mainClass>${app.main.class}</mainClass>
              </manifest>
            </archive>
            <instructions>
              <Embed-Dependency>*;inline=false;scope=compile</Embed-Dependency>
              <Embed-Transitive>true</Embed-Transitive>
              <Embed-Directory>lib</Embed-Directory>
            </instructions>
          </configuration>
          <executions>
            <execution>
              <phase>package</phase>
              <goals>
                <goal>bundle</goal>
              </goals>
            </execution>
          </executions>
        </plugin>
      </plugins>
    </pluginManagement>
    <plugins>
      <plugin>
        <groupId>net.alchim31.maven</groupId>
        <artifactId>scala-maven-plugin</artifactId>
        <version>3.2.0</version>
        <executions>
          <execution>
            <goals>
              <goal>compile</goal>
              <goal>testCompile</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <jvmArgs>
            <jvmArg>-Xms256m</jvmArg>
            <jvmArg>-Xmx2048m</jvmArg>
          </jvmArgs>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.12</version>
        <configuration>
          <skipTests>true</skipTests>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.scalatest</groupId>
        <artifactId>scalatest-maven-plugin</artifactId>
        <version>1.0</version>
        <configuration>
          <reportsDirectory>${project.build.directory}/surefire-reports</reportsDirectory>
          <junitxml>.</junitxml>
          <filereports>WDF TestSuite.txt</filereports>
        </configuration>
        <executions>
          <execution>
            <id>test</id>
            <goals>
              <goal>test</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>2.4</version>
        <executions>
          <execution>
            <id>copy-dependencies</id>
            <phase>package</phase>
            <goals>
              <goal>copy-dependencies</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>2.4.1</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <artifactSet>
                <excludes>
                  <exclude>junit:junit</exclude>
                  <exclude>org.apache.maven:lib:tests</exclude>
                  <exclude>log4j:log4j:jar:</exclude>
                  <exclude>slf4j</exclude>
                  <exclude>org.scala-lang</exclude>
                  <exclude>org.apache.hadoop</exclude>
                  <exclude>org.apache.curator</exclude>
                  <exclude>org.apache.commons</exclude>
                  <exclude>org.apache.spark</exclude>
                  <exclude>javax.activation</exclude>
                  <exclude>javax.annotation</exclude>
                  <exclude>javax.inject</exclude>
                  <exclude>javax.servlet</exclude>
                  <exclude>javax.xml</exclude>
                  <exclude>io.netty</exclude>
                  <exclude>io.dropwizard.metrics</exclude>
                  <exclude>com.twitter</exclude>
                  <exclude>org.joda</exclude>
                  <exclude>com.fasterxml.jackson.core</exclude>
                </excludes>
              </artifactSet>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Are you *sure* it's the right package? Do you actually have a class called "App" in the package called my.jar? — Christian Neverdal, Jul 20 '16 at 12:55
what's `app.main.class`? is this property used somewhere in the pom file? can you share more of your `pom.xml` file? — A_Di-Matteo, Jul 20 '16 at 12:56
@ChristianJonassen I usually run my jars from spark, with a `--class` flag. First time I try to run a non-Spark jar.. — shakedzy, Jul 20 '16 at 16:15
Never tried that. Are you sure that that technique uses the JAR at all? There might be other issues. — Christian Neverdal, Jul 20 '16 at 17:44
@ChristianJonassen I get `no main manifest attribute, in target/jar_2.10.jar` — shakedzy, Jul 20 '16 at 19:54
Please create a minimal project and put it on GitHub or something like that and we can all have a deeper look at it. — Christian Neverdal, Jul 21 '16 at 13:43

Can't run Scala jar from command line

0 Answers0