How to compile and run rosjava Hello World

edit

gradle install approach still does not work, but compilation now works with copy-paste gradlew. I had the gradle configuration files inside the package folder instead of outside.

Edit:

Nope, still problems :-). Forget what I wrote before.

I can build the example packages in the rosjava_core folder as described in (http://docs.rosjava.googlecode.com/hg/rosjava_core/html/getting_started.html).

What I did next was copy pasting the example package "rosjava_tutorial_pubsub" and renaming the package to "rosjava_testPackage" as a test. In the folder rosjava_testPackage I renamed everything accordingly. But now ../gradlew installApp yields the errors:

FAILURE: Build failed with an exception.

* Where:
Build file '/home/userName/ros_workspace/rosjava_core/rosjava_testPackage/build.gradle'
line: 22

* What went wrong:
A problem occurred evaluating root project 'rosjava_testPackage'.
Project with path ':rosjava' could not be found in root project 'rosjava_testPackage'.

* Try:
Run with --stacktrace option to get the stack trace. 
Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 0.834 secs

I used the same gradlebuild file as in the example package "rosjava_tutorial_pubsub", which looks like this:

/* .... */

apply plugin: 'application'

mainClassName = 'org.ros.RosRun'

dependencies {
  compile project(':rosjava')
}

Line 22 refers to "compile project(':rosjava')".

How can there be errors if the test package is a renamed copy of the tutorial package?

Edit 2: Problem solved. I had to manually register the package in gradle settings.