From Maven, how do I run a class that lives under src/test/java?

Question

I have inherited a codebase :)

Under src/test/java/ there's a file that I need to run (I need to run its public static void main(String[] args), not a @Test method within it).

The closest I have got is:

mvn -e exec:java -Dexec.mainClass="com.me.packagex.RunFile" -Dexec.classpathScope="test"

but that then fails, and it appears to be because RunFile wants to use classes that exist under src/main/java/com/me/packagex/ (notice, /main/, not /test/). The files under there are in the same package as RunFile, i.e. 'package com.me.packagex;'.

If I remove the -Dexec.classpathScope="test" then it can't find RunFile at all. It's as if I need to give it two scopes, but it doesn't accept "test,compile".

The person I've inherited this from (dearly departed) used to run it from Eclipse. I need a way to run it from the command-line.

I hope this is clearly explained.

tyvm,

---

This is promising. Pascal, I've tried your example and that doesn't work for me.

Although now I look at it - it's not finding Demo, rather than not finding Dog.

Apache Maven 2.2.1 (rdebian-1)
Java version: 1.6.0_18
Java home: /usr/lib/jvm/java-6-openjdk/jre
Default locale: en_GB, platform encoding: UTF-8
OS name: "linux" version: "2.6.32-25-generic" arch: "i386" Family: "unix"

$ mvn -e exec:java -Dexec.mainClass="com.stackoverflow.Demo" -Dexec.classpathScope="test"

[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] An exception occured while executing the Java class. com.stackoverflow.Demo

[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: An exception occured while executing the Java class. com.stackoverflow.Demo
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:719)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:569)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:539)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
        at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
        at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
        at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
        at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.MojoExecutionException: An exception occured while executing the Java class. com.stackoverflow.Demo
        at org.codehaus.mojo.exec.ExecJavaMojo.execute(ExecJavaMojo.java:346)
        at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
        ... 17 more
Caused by: java.lang.ClassNotFoundException: com.stackoverflow.Demo
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:284)
        at java.lang.Thread.run(Thread.java:619)

Answer 1

I faced the same problem and figured it out.

Shortly speaking, the class must be compiled before exec:java goal. (It surely works without test-compile phase if the class is already compiled by other user action. Note that Pascal Thivent, in his answer, invoked mvn test before exec:java.)

$ mvn -Dexec.mainClass=... -Dexec.classpathScope=test test-compile exec:java

You can prove it for yourself if you want to see the ClassNotFoundException again.

$ mvn -Dexec.mainClass=... -Dexec.classpathScope=test clean exec:java