Run main of specific class inside a package subdirectory

Question

I am following Scheduled Jobs with Custom Clock Processes in Java with Quartz and RabbitMQ but I struggle to actually run another dyno from withing the jar file packeg by Spring.

In the package (server-1.0-SNAPSHOT.jar) I need to run the company.server.Scheduler. The .class file is in BOOT-INF/classes.

I've tried to do this but I am always getting

Error: Could not find or load main class company.server.Scheduler

I'm struggling to get the syntax right.

So what I need to run is

BOOT-INF/classes/company/server/Scheduler.class

I have tried this:

java -classpath BOOT-INF/classes -jar server-1.0-SNAPSHOT.jar company.server.Scheduler
java -classpath server-1.0-SNAPSHOT.jar:/BOOT-INF/classes company.server.Scheduler

But this either runs the main class from the Manifest or crashes.

Also tried:

java -classpath server-1.0-SNAPSHOT.jar BOOT-INF.classes.company.server.Scheduler
java -classpath server-1.0-SNAPSHOT.jar BOOT-INF/classes/company/server/Scheduler

Try it out ...

git clone https://github.com/silentsnooc/run-scheduler
cd run-scheduler/
mvn clean install
cd target/
java -cp .:scheduler-test-1.0-SNAPSHOT.jar BOOT-INF.classes.Scheduler

If I follow this on Heroku then it should be something like

java -cp scheduler-test-1.0-SNAPSHOT.jar:BOOT-INF/classes/* Scheduler

but it's not working telling me the main class Scheduler could not be found.

@TimothyTruckle Yes. This jar file gets packaged by Spring which is moving all the compiled stuff into `BOOT-INF/classes` afaik. — Stefan Falk, Dec 29 '18 at 18:39
then try `java -classpath server-1.0-SNAPSHOT.jar BOOT-INF.classes.company.server.Scheduler` — Timothy Truckle, Dec 29 '18 at 18:41
@TimothyTruckle Just tried it. It does not work unfortunately. Could it be because `BOOT-INF` is not a vaild package name? — Stefan Falk, Dec 29 '18 at 18:42
@TimothyTruckle Yes. That produces `Could not find or load main class ...` again. — Stefan Falk, Dec 29 '18 at 18:45
Try adding `-cp .` to your java call. That will add the current dir to the classpath. — Sam Orozco, Dec 29 '18 at 18:48
Is `BOOT-INF/classes` part of the manifests *ClassPath* entry? — Timothy Truckle, Dec 29 '18 at 18:50
@SamOrozco I'm currently at `java -cp . -classpath server-1.0-SNAPSHOT.jar BOOT-INF.classes.company.server.Scheduler` — Stefan Falk, Dec 29 '18 at 18:50
Try this: `java -cp .:server-1.0-SNAPSHOT.jar BOOT-INF.classes.company.server.Scheduler` or this `java -cp ".:server-1.0-SNAPSHOT.jar" BOOT-INF.classes.company.server.Scheduler` — Sam Orozco, Dec 29 '18 at 18:51
@TimothyTruckle I can't see a ClassPath entry in the manifest file. All I see is `Main-Class: org.springframework.boot.loader.JarLauncher` and a few other things. The only mention of that directory is in `Spring-Boot-Classes: BOOT-INF/classes/`. — Stefan Falk, Dec 29 '18 at 18:52
I suggest a *delegation* class in the regular package structure. — Timothy Truckle, Dec 29 '18 at 18:55
@TimothyTruckle Now sure how to do that? In the meantime I created a little github repo which should generate a simple jar. (https://github.com/silentsnooc/run-scheduler) — Stefan Falk, Dec 29 '18 at 19:01

Run main of specific class inside a package subdirectory

Try it out ...

0 Answers0