Grails create a service from a factory - grails

Question

I would like to utilize a service written in Java in my Grails app using dependency injection. Creating it in Java without injection would look like this:
ServiceFactory.newInstance().getElementService()
I would like to use this in the same way services are injected for controllers, services, and jobs.
class ImportJob {
def elementService
...
}
I know this should go into resources.groovy and this is what I have so far:
serviceFactory(ServiceFactory) { bean ->
bean.factoryMethod = 'newInstance'
}
elementService(ElementService) {
}
I have found few resources in the documentation to help with this. How do I complete the elementService so it is creating the object as described above? Should I use a BeanBuilder?

Answer 1

You could create a FactoryBean for this since it's not as direct as calling a method in a class:
package com.mycompany
import org.springframework.beans.factory.FactoryBean
import org.springframework.beans.factory.InitializingBean
class ElementServiceFactoryBean implements FactoryBean<ElementService>, InitializingBean {
private ElementService elementService
ElementService getObject() { elementService }
Class<ElementService> getObjectType() { ElementService }
boolean isSingleton() { true }
void afterPropertiesSet() {
elementService = ServiceFactory.newInstance().elementService
}
}
and you'd register it in resources.groovy as
elementService(ElementServiceFactoryBean)

Answer 2

Use bean.factoryMethod and bean.factoryBean in the elementService bean.
serviceFactory(ServiceFactory) { bean ->
bean.factoryMethod = 'newInstance'
bean.scope = 'singleton'
}
elementService(ElementService) { bean ->
bean.factoryMethod = 'getElementService'
bean.factoryBean = 'serviceFactory'
}
This is a simple solution especially if ServiceFactory is external and cannot be changed.