I got the following errors when running:
$ mvn -X -e -q exec:java
-Dexec.mainClass="org.apache.mahout.cf.taste.example.netflix.NetflixRecommenderEvaluatorRunner"
-Dexec.args="-i /home/yyang/work/mahout/trunk/examples/data/ml-1m/"
[DEBUG] joining on thread
Thread[org.apache.mahout.cf.taste.example.netflix.NetflixRecommenderEvaluatorRunner.main(),5,org.apache.mahout.cf.taste.example.netflix.NetflixRecommenderEvaluatorRunner]
[DEBUG] Setting accessibility to true in order to invoke main().
11/10/21 13:52:01 INFO netflix.NetflixDataModel: Creating
NetflixDataModel for directory:
/home/yyang/work/mahout/trunk/examples/data/ml-1m
11/10/21 13:52:01 INFO netflix.NetflixDataModel: Reading preference data...
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] An exception occured while executing the Java class. null
[INFO] ------------------------------------------------------------------------
[DEBUG] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: An exception
occured while executing the Java class. null
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:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
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. null
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.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:291)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.NullPointerException
at
org.apache.mahout.cf.taste.example.netflix.NetflixDataModel.readUsers(NetflixDataModel.java:79)
at
org.apache.mahout.cf.taste.example.netflix.NetflixDataModel.<init>(NetflixDataModel.java:68)
at
org.apache.mahout.cf.taste.example.netflix.NetflixRecommenderEvaluatorRunner.main(NetflixRecommenderEvaluatorRunner.java:44)
... 6 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2 seconds
[INFO] Finished at: Fri Oct 21 13:52:01 PDT 2011
[INFO] Final Memory: 23M/127M
[INFO] ------------------------------------------------------------------------
On Fri, Oct 21, 2011 at 1:21 AM, Sean Owen <[email protected]> wrote:
> It depends on which example you are running! For GroupLens, yes, it's
> the movies.dat file.
>
> I will warn you that I think the various GroupLens data sets have
> different input formats. Some are comma-separated, which is what you
> need, and some are separated by "::". Open the file and look. If it is
> the latter, you need to change it to comma-separated form.
>
> On Thu, Oct 20, 2011 at 11:41 PM, Yang <[email protected]> wrote:
>> in the recommendation examples
>>
>> https://cwiki.apache.org/confluence/display/MAHOUT/RecommendationExamples
>>
>> it mentions the "-i input_file " parameter,
>>
>> but the downloaded movie-lens dataset is a zip, and contains multiple
>> .dat files, which one should I use?
>>
>> Thanks
>> Yang
>>
>
how do I debug this?
