Groovy: Log Annotation

PROBLEM

My personal goal of 2017 is to write less useless-yet-neccessary code, such as initializing a logger:-

import org.slf4j.Logger
import org.slf4j.LoggerFactory

class MyClass {
    static Logger LOGGER = LoggerFactory.getLogger(MyClass)

    static void main(String[] args) {
        LOGGER.debug('TEST')
    }
}

SOLUTION

Groovy provides several useful annotations that allow us to inject a logger instance into the class.

Here’s a rewrite of the above example:-

import groovy.util.logging.Slf4j

@Slf4j
class MyClass {
    static void main(String[] args) {
        log.debug('TEST')
    }
}

If we insist of using the same variable ( LOGGER ), we can do this:-

import groovy.util.logging.Slf4j

@Slf4j(value = 'LOGGER')
class MyClass {
    static void main(String[] args) {
        LOGGER.debug('TEST')
    }
}

We can also use @Log for Java Util Logger, @Log4j for Log4j and @Commons for Apache Common Logging.