I started playing around with Grails again recently and ran into a problem trying to create a bean in the Grails resources.groovy file for a static factory. After several frustrating hours trying to find the right combination, I eventually stumbled upon an answer.

The factory I was trying to create a bean from was the JAX-RS Client API class ClientBuilder.newClient() which returns a Client object.

Here is what the bean definition looks like in my Grails resources.groovy file:

import javax.ws.rs.client.ClientBuilder
 
beans = {
    httpClient(ClientBuilder) { bean ->
        bean.factoryMethod = 'newClient'
        bean.destroyMethod = 'close'
    }
}

Then in your Grails service or controller you can autowire or inject the bean by doing the following:

class FooService {
    def httpClient
 
    def get(url) {
        return httpClient.target(url).request().get()
    }
}

Hope it helps the next person.