Hi Ceki, the only thing that I don't understand is why Appender requires a layout at all. It would by cleaner if there was a sub-interface, e.g. LayoutAwareAooender (just a spontaneous suggestion), that extended Appender and would add said methods. Some appenders, like SocketAppender or some fictitious appender that would simply serialize the events to a file (I'm planning to implement such an appender, btw), just don't need a layout at all. AppenderBase would then just implement the basic Appender interface, leaving the layout implementation to appenders that would really require it. This topic is covered by both http://jira.qos.ch/browse/LBCORE-1 and http://jira.qos.ch/browse/LBCORE-56 Regards, Joern. On 09.02.2009, at 19:50, Ceki Gulcu wrote:
Hello all,
While working on chapter 11, migration of log4j appenders to logback-classic, it occured to me that the current way AppenderBase implements its layout setter and getter can be confusing. Here is the relevant code:
abstract public class AppenderBase<E> extends ContextAwareBase implements Appender<E> {
public Layout<E> getLayout() { return null; }
public void setLayout(Layout<E> layout) { }
// omitted code }
The fact that the setLayout does nothing and getLayout always returns null is somethat unexpected and may suprise users. This has apparently already happended to Thilo Tanner as reported in LBCORE-56. See also http://jira.qos.ch/browse/LBCORE-56
I'd like to change AppenderBase to:
abstract public class AppenderBase<E> extends ContextAwareBase implements Appender<E> {
Layout<E> layout;
public Layout<E> getLayout() { return layout; }
public void setLayout(Layout<E> layout) { this.layout = layout; }
// omitted code }
The new code offers a reasonable default implementation for layout getter and setter methods. It should decrease the aforementioned surprise factor without causing harm to many appender implementations which do not need a layout.
Comments?
-- Ceki Gülcü Logback: The reliable, generic, fast and flexible logging framework for Java. http://logback.qos.ch _______________________________________________ logback-dev mailing list logback-dev@qos.ch http://qos.ch/mailman/listinfo/logback-dev