CODEWITHSUNDEEP
javamavenheroku
oz123
oz123

Reputation: 28868

maven not found on heroku - how to run my java app?

Simple as that, I am trying to deploy this app https://github.com/pac4j/spark-pac4j-demo to my heroku instance.

I can run it locally with: mvn compile exec:java

But on heroku, there is no maven installed:

2016-04-12T18:34:21.074629+00:00 heroku[web.1]: Starting process with command `mvn compile exec:java`
2016-04-12T18:34:23.303776+00:00 app[web.1]: bash: mvn: command not found
2016-04-12T18:34:23.303620+00:00 app[web.1]: Setting JAVA_TOOL_OPTIONS defaults based on dyno size. Custom settings will override them.

I have no clue how to set all the class paths per hand. I would appreciate some help here.

Upvotes: 0

Views: 1146

Answers (1)

codefinger
codefinger

Reputation: 10318

You'll first need to vendor your dependencies (i.e. copy them into the target/ directory). You can do so by adding this to your pom.xml:

  <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>

Then the correct command to run the app will probably be something like java -cp target/classes:target/dependency/* Main (where Main should be replaced with your class that contains the public static void main method).

Here is a sample app using Spark so you can see how this all comes together.

Maven is not a good way to run an application in production. It creates an additional dependency for your app and adds layers of indirection to the process execution.

Upvotes: 1

Related Questions