pom.xml changes for running FirstHop.java with jackrabbit 2.22.x

[lmuppidi]

From examples, FirstHop doesn't work as is from GitHub when 2.22.x is installed.
Made changes to pom.xml to address following issues

1. JDK version
2. Added dependency for missing jackrabbit-jcr-commons
3. Added version for 1.7.36
4. Added org.apache.derby version as 10.14.2.0 to address missing EmbeddedDriver class issue while running FirstHop.java using the command mvn exec:java -Dexec.mainClass="org.apache.jackrabbit.firsthops.FirstHop"

[lmuppidi]

Please review the changes.

[reschke]

Thanks for the report. Seems it hasb't been tried for ages.

I fixed a few things in #302 (branch: JCR-5198), but I'm not sure about your Derby issue.

How do I check that?

[lmuppidi]

I got this runtime error while trying to run the FirstHop example class.
mvn exec:java -Dexec.mainClass="org.apache.jackrabbit.firsthops.FirstHop"

Exception:-
java.lang.ClassNotFoundException: org.apache.derby.jdbc.EmbeddedDriver
javax.jcr.RepositoryException: Cannot instantiate persistence manager

Attached the complete stack trace.
FirstHop Exception Stack Trace.rtf

[reschke]

I am (with my changes) getting:

[WARNING]
java.lang.Exception: The specified mainClass doesn't contain a main method with appropriate signature.
    at org.codehaus.mojo.exec.ExecJavaMojo.lambda$execute$0 (ExecJavaMojo.java:294)
    at java.lang.Thread.run (Thread.java:834)
Caused by: java.lang.NoSuchMethodException: No suitable main method found for class org.apache.jackrabbit.firsthops.FirstHop, and not Runnable
    at org.codehaus.mojo.exec.ExecJavaMojo.doExec (ExecJavaMojo.java:404)
    at org.codehaus.mojo.exec.ExecJavaMojo.lambda$execute$0 (ExecJavaMojo.java:289)
    at java.lang.Thread.run (Thread.java:834)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.082 s
[INFO] Finished at: 2025-10-14T18:29:47+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.6.1:java (default-cli) on project jackrabbit-firsthops: An exception occurred while executing the Java class. The specified mainClass doesn't contain a main method with appropriate signature.: No suitable main method found for class org.apache.jackrabbit.firsthops.FirstHop, and not Runnable -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

[lmuppidi]

I do see the main method in the Java file (Github). Are you compiling it in Jdk11?

public static void main(String[] args) throws Exception { Repository repository = JcrUtils.getRepository(); Session session = repository.login(new GuestCredentials()); try { String user = session.getUserID(); String name = repository.getDescriptor(Repository.REP_NAME_DESC); System.out.println("Logged in as " + user + " to a " + name + " repository."); } finally { session.logout(); } }

[reschke]

Yes.

$ echo $JAVA_HOME/
/lib/jvm/jdk-11.0.27/

This is really strange.

[lmuppidi]

Did you apply the pom.xml changes from this pull request for running FirstHop locally.
pom.xml was using java 1.5 before the change. Also check the version for exec-maven-plugin

[reschke]

Please check with my changes in https://issues.apache.org/jira/browse/JCR-5198 (#302)

[lmuppidi]

Yes I get the same error with your pom.xml changes. May be classloading issue with the Maven exec plugin...

[lmuppidi]

Please review the changes again