Question

How do I build an outside Gradle project from a Grails controller? Grails 2.0.0

UPDATE:
I emailed Adam Murdoch (co-founder of gradle) about this question: http://forums.gradle.org/gradle/topics/how_can_i_use_the_gradle_tooling_api_from_a_grails_controller

While, I don’t have a direct answer to this question, I do have a solution.
Any further insights on this subject would be greatly appreciated.

---

I used a gradle build script provided by Luke Daley. Ran build.gradle, and it output 4 jar files needed for gradle tooling api. I then put these into my Grails lib folder.

I then wrote the following code into my grails controller called consoleController.groovy.

import org.gradle.tooling.BuildLauncher
import org.gradle.tooling.GradleConnector
import org.gradle.tooling.ProjectConnection

class consoleController {
   def run = {
       println "new run -------------------------------------"
       println "Building file..."

       String projectDir = "C:\\Documents and Settings\\Administrator\\Desktop\\demo"
       GradleConnector connector = GradleConnector.newConnector()
       connector.forProjectDirectory(new File(projectDir))

       ProjectConnection connection = connector.connect()
       try {
           BuildLauncher launcher = connection.newBuild()
           launcher.forTasks("hello")
           launcher.run()
       } finally {
           connection.close()
       }
    }
 }

I also created a directory called “demo” – with a build.gradle file.

task hello {
    println "hello world"
}

I get the following stack trace – errors:
PLEASE SEE – http://forums.gradle.org/gradle/topics/how_can_i_use_the_gradle_tooling_api_from_a_grails_controller

Stack trace is too long for StackOverflow.com.

Answer 1

You may visit the post entitled http://forums.gradle.org/gradle/topics/how_can_i_use_the_gradle_tooling_api_from_a_grails_controller
which provides directions for setting-up a minimal grails project for embedding the grails tooling API, and allows a user to trigger builds from a grails controller.

Grails 2.0.0 should fully support the Gradle tooling API out of the box, but Spring Loaded a technology that enables hot-reloading of classes gets in the way of the gradle tooling API, and throws an error:
java.lang.ClassNotFoundException: com.springsource.loaded.ri.ReflectiveInterceptor
– when trying to build.

Running the grails app with the -noreloading flag, solves the problem.

> grails -noreloading run-app

An alternative to Grails embedding, that would still allow builds to be triggered from a Grails controller would be to use a Continuous Integration server that supports REST, such as Jenkins (TeamCity, Bamboo, CruiseControl, etc.); while, this is not a direct solution to this question, these enterprise applications provide an alternative to Gradle embedding and are probably better suited for enterprise offerings.

Cheers, TFM