I appreciate the input although considering that DBNameResolver is a mere component of DBAppender, using generics in this case is probably not the best design one can come up with. On 26.02.2010 13:27, Durchholz, Joachim wrote:
(If logback can use generic classes, then DBAppender<DBNameResolver> would be optimal IMHO.)
Right, http://logback.qos.ch/dependencies.html says Java 1.5.
Here's a design outline with generics. I left out enums because I'm not so sure whether they're such a great idea after all, and because it works just fine without them :)
First, the base class:
class DBAppender<DBNameResolver> { // Uses dbNameResolver.getEventTableName etc. } class DBNameResolver { String getEventTableName () { return "logging_event"; } String getTimestampColumnName () { return "timestmp"; } String getFormattedMessageColumnName () { return "formatted_message"; } ... String getEventPropertyTableName () { return "logging_event_property"; } ... String getEventExceptionTableName () { return "logging_event_exception"; } ... }
A variant for storing log parameters:
class DBAppenderWithParameters<DbNameResolverWithParameters> { // Uses new dbNameResolver function getArgumentColumnNames // to construct the INSERT statement } class DbNameResolverWithParameters extends DBNameResolver { // Keep inherited definitions, just add the parameter column names String [] argumentColumnNames = new String [] {"arg1", "arg2", "arg3", "arg4", "arg5", "arg5", "arg7", "arg8"}; String [] getArgumentColumnNames { return argumentColumNames; } }
HTH Jo