October 23, 2009

Groovy Goodness: Static Imports

Java already has static imports, but Groovy takes it to the next level. In a previous post we learned how we use the as keyword to assign a class we import to a variable in the import statement. But with static imports we can do this even for static methods and properties. This makes for code which may confuse us, but if we look at the import section all will be revealed.

import static HttpURLConnection.HTTP_OK  // Normal Java static import.
import static HttpURLConnection.HTTP_OK as okay 
import static HttpURLConnection.setFollowRedirects as redirect
import as http // Non static import.

redirect false  // HttpURLConnection.setFollowRedirects(false)
assert false == HttpURLConnection.followRedirects

def c = (http) ''.toURL().openConnection()
assert c instanceof HttpURLConnection

assert okay == c.responseCode
assert HTTP_OK == c.responseCode