Error: Could not find or load main class in scala - scala

Question

After installing eclipse scala plugins and eclipse maven plugin for scala .
I am new to scala , so i tried to so ensured that the enviorment was working after testing a scala hello world project. It works as expected.
But i am facing difficulty while trying to execute the project that i had checked out from the company's repository. No matter what I do (clean,build, clean-install via mave etc) I am getting a "Error: Could not find or load main class com.company.team.spark.sqlutil.testQuery" while trying to run even a small hello world program inside the project. My hunch says eclipse is unable to create class files for the project due to a pom issse, but I am unable to nail it down even after several tries. Please help me to figure this out
Version: Eclipse Luna Release (4.4.0)
Build id: 20140612-0600
scala - 2.10.6
Scalacode - testQuery.scala
package com.company.team.spark.sqlutil
object testQuery {
def main(args: Array[String]): Unit = {
print ("Hello")
}
}
Below is the POM I used.
<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.company.team.spark</groupId>
<artifactId>HomeSpark</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>HomeSpark</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<lib.dir>${project.basedir}\lib\</lib.dir>
</properties>
<dependencies>
<!-- <dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>system</scope>
<systemPath>${lib.dir}junit-3.8.1.jar</systemPath>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>2.1.0</version>
<scope>system</scope>
<systemPath>${lib.dir}spark-core_2.10-2.1.0.jar</systemPath>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.10</artifactId>
<version>2.1.0</version>
<scope>system</scope>
<systemPath>${lib.dir}spark-sql_2.10-2.1.0.jar</systemPath>
</dependency>
<dependency>
<groupId>com.databricks</groupId>
<artifactId>spark-csv_2.10</artifactId>
<version>1.5.0</version>
<scope>system</scope>
<systemPath>${lib.dir}spark-csv_2.10-1.5.0.jar</systemPath>
</dependency> -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.10 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>2.1.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql_2.10 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.10</artifactId>
<version>2.1.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.databricks/spark-csv_2.10 -->
<dependency>
<groupId>com.databricks</groupId>
<artifactId>spark-csv_2.10</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.9.2</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>${project.basedir}/src/main/scala</sourceDirectory>
<testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
<plugins><plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.1.3</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin></plugins>
</build>
</project>
Link to image of project structure

Answer 1

Use compile install as required for scala-maven-plugin. You might be using clean install which is deleting generated .class files from /bin, eclipse could not find or load main class.

Answer 2

I was able to resolve the issues after opted for scala IDE over eclipse integrated with scala IDE plugin.
Also changed the pom.xml to the following:
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.company.fuison</groupId>
<artifactId>SomeCloud</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>${project.artifactId}</name>
<description>My wonderfull scala app</description>
<inceptionYear>2015</inceptionYear>
<licenses>
<license>
<name>My License</name>
<url>http://....</url>
<distribution>repo</distribution>
</license>
</licenses>
<properties>
<maven.compiler.source>1.6</maven.compiler.source>
<maven.compiler.target>1.6</maven.compiler.target>
<encoding>UTF-8</encoding>
<scala.version>2.11.5</scala.version>
<scala.compat.version>2.11</scala.compat.version>
</properties>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.0.0</version>
</dependency>
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.9.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.databricks/spark-csv_2.11 -->
<dependency>
<groupId>com.databricks</groupId>
<artifactId>spark-csv_2.11</artifactId>
<version>1.5.0</version>
</dependency>
<!-- Test -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.specs2</groupId>
<artifactId>specs2-core_${scala.compat.version}</artifactId>
<version>2.4.16</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.scalatest</groupId>
<artifactId>scalatest_${scala.compat.version}</artifactId>
<version>2.2.4</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.specs2</groupId>
<artifactId>specs2-junit_${scala.compat.version}</artifactId>
<version>2.4.16</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api-scala_2.11</artifactId>
<version>2.8.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.8.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.scala-lang/scala-library
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>2.12.1</version>
</dependency>
-->
<!-- https://mvnrepository.com/artifact/com.typesafe.scala-logging/scala-logging_2.11 -->
<dependency>
<groupId>com.typesafe.scala-logging</groupId>
<artifactId>scala-logging_2.11</artifactId>
<version>3.5.0</version>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>${project.basedir}/config/log4j</directory>
</resource>
</resources>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<!-- see http://davidb.github.com/scala-maven-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>
<configuration>
<args>
<arg>-dependencyfile</arg>
<arg>${project.build.directory}/.scala_dependencies</arg>
</args>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<useFile>false</useFile>
<disableXmlReport>true</disableXmlReport>
<!-- If you have classpath issue like NoDefClassError,... -->
<!-- useManifestOnlyJar>false</useManifestOnlyJar -->
<includes>
<include>**/*Test.*</include>
<include>**/*Suite.*</include>
</includes>
</configuration>
</plugin>
</plugins>
</build>
</project>