Running a scala application in maven project

Question

I am trying to use maven to handle dependencies in a scala project in Eclipse. But once the project is converted to maven, the application wont run anymore.

Here is the steps to reproduce :

1) new scala project

• project name : test
• finish

2) new scala object

• name : hello_world
• finish

3) hello_world.scala

package test

object hello_world {
  def main(args: Array[String]) {
    println("Hello world !!!")
  }
}

4) run scala application

• project : test
• main class : test.hello_world

result : working, hello world is printed

5) right clic on project -> configure -> convert to mavem project

• group id : test
• artifact id : test
• version : 0.0.1-SNAPSHOT
• packaging : jar
• finish

6) run scala application

• project : test
• main class : test.hello_world

result :

Error: Could not find or load main class test.hello_world

Versions details :

Eclipse 4.4.1 M2E 1.5.0 Scala IDE for Eclipse 4.0.0.nightly-2_11

Generated 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>test</groupId>
  <artifactId>test</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <resources>
      <resource>
        <directory>src</directory>
        <excludes>
          <exclude>**/*.java</exclude>
        </excludes>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Solution 1

http://scala-tools.org/repo-releases is deprecated, here is a working 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>test</groupId>
<artifactId>test</artifactId>
<version>0.0.1-SNAPSHOT</version>

<repositories>
    <repository>
        <id>scala-tools.org</id>
        <name>Scala-tools Maven2 Repository</name>
        <url>https://oss.sonatype.org/content/groups/scala-tools/</url>
    </repository>
</repositories>

<pluginRepositories>
    <pluginRepository>
        <id>scala-tools.org</id>
        <name>Scala-tools Maven2 Repository</name>
        <url>https://oss.sonatype.org/content/groups/scala-tools/</url>
    </pluginRepository>
</pluginRepositories>

<dependencies>
    <dependency>
        <groupId>org.scala-lang</groupId>
        <artifactId>scala-library</artifactId>
        <version>2.11.4</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <sourceDirectory>src</sourceDirectory>
    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>maven-scala-plugin</artifactId>
                <version>3.2.0</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
            </plugin>
        </plugins>
    </pluginManagement>
    <plugins>
        <plugin>
            <groupId>org.scala-tools</groupId>
            <artifactId>maven-scala-plugin</artifactId>
            <executions>
                <execution>
                    <id>scala-compile-first</id>
                    <phase>process-resources</phase>
                    <goals>
                        <goal>add-source</goal>
                        <goal>compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

</project>

To run the application :

run -> scala application

• project : test
• main class : test.hello_world

Solution 2

Your pom.xml should contain these parts (change the versions of course):

Repositories:

    <repositories>
        <repository>
            <id>scala-tools.org</id>
            <name>Scala-Tools Maven2 Repository</name>
            <url>http://scala-tools.org/repo-releases</url>
        </repository>
    </repositories>

Plugin repositories:

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

Dependencies:

<dependencies>
    <dependency>
        <groupId>org.scala-lang</groupId>
        <artifactId>scala-library</artifactId>
        <version>${scala.version}</version>
    </dependency>
</dependencies>

Build:

<build>
    <pluginManagement>
        <plugins>
            <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>
            </plugin>
        </plugins>
    </pluginManagement>
    <plugins>
        <plugin>
            <groupId>org.scala-tools</groupId>
            <artifactId>maven-scala-plugin</artifactId>
            <executions>
                <execution>
                    <id>scala-compile-first</id>
                    <phase>process-resources</phase>
                    <goals>
                        <goal>add-source</goal>
                        <goal>compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Solution 3

Go to

project properties->Select scala compiler->Select scala installation and change to scala-2.10->apply->close

Run

     maven clean

Run Scala application

then you cant see the output in Console