rspec/rules/S1312/java/rule.adoc

== Why is this an issue?

Regardless of the logging framework in use (logback, log4j, commons-logging, java.util.logging, ...), loggers should be:


* ``++private++``: never be accessible outside of its parent class. If another class needs to log something, it should instantiate its own logger.
* ``++static++``: not be dependent on an instance of a class (an object). When logging something, contextual information can of course be provided in the messages but the logger should be created at class level to prevent creating a logger along with each object.
* ``++final++``: be created once and only once per class.

=== Noncompliant code example

With a default regular expression of ``++LOG(?:GER)?++``:

[source,java]
----
public Logger logger = LoggerFactory.getLogger(Foo.class);  // Noncompliant
----

=== Compliant solution

[source,java]
----
private static final Logger LOGGER = LoggerFactory.getLogger(Foo.class);
----

=== Exceptions

Variables of type ``++org.apache.maven.plugin.logging.Log++`` are ignored.

include::../rspecator.adoc[]