Question

This question is probably going to illustrate a lack of knowledge on my part about how Groovy classes work, but I have tried to figure this out on my own with no luck. I want to create a getProperty() method on a class so I can reference member variables in a Groovyish way. This is NOT the same as just making them public because I do want some logic done when they are referenced. Basically, I’m trying to create a configuration Groovy class that uses ConfigSlurper:

class Configuration implements GroovyObject {
  private static ConfigObject config  = new ConfigSlurper().parse(new File("testing.conf").toURI().toURL())

  //This method is illegal, but it illustrates what I want to do
  public static String getProperty(String prop){
    config.getProperty(prop)
  }
}

If the above class were legal, I could then reference config items like so:

Configuration.dbUser

instead of this, which would require making the ConfigObject available:

Configuration.config.dbUser

I know, it would be worlds easier to just make the config object public, but knowing how to do this (or know why it’s impossible) would help me understand Groovy a little better.

Answer 1

The only way I can get it to work is via the metaClass:

class Configuration {
  private static ConfigObject config  = new ConfigSlurper().parse( "foo = 'bar'" )
}

Configuration.metaClass.static.propertyMissing = { name ->
  delegate.config[ name ]
}

println Configuration.foo

There may be a better way however…