As an alternative to writing Java code for custom formatting, Velocity templates can be a good alternative to quickly prototype formatters. For example, the following template could be specified as the format of a JMS or file handler:

Transaction: numOps='$tx.size' ts='$tx.timestamp'
#for each( $op in $tx )
operation: $op.sqlType, on table "$op.tableName":
#for each( $col in $op )
$op.tableName, $col.meta.columnName = $col.value
#end
#end

If the template were named sample.vm, it could be placed in the classpath, for example:

gg_install_dir/dirprm/sample.vm
	

Update the Java application properties file to use the template:

# set properties on 'one'
gg.handler.one.type=file
gg.handler.one.format=sample.vm
gg.handler.one.file=output.xml

When modifying templates, there is no need to recompile any Java source; simply save the template and re-run the Java application. When the application is run, the following output would be generated (assuming a table named SCHEMA.SOMETABLE, with columns TESTCOLA and TESTCOLB):

Transaction: numOps='3' ts='2008-12-31 12:34:56.000'
operation: UPDATE, on table "SCHEMA.SOMETABLE":
SCHEMA.SOMETABLE, TESTCOLA = value 123
SCHEMA.SOMETABLE, TESTCOLB = value abc
operation: UPDATE, on table "SCHEMA.SOMETABLE":
SCHEMA.SOMETABLE, TESTCOLA = value 456
SCHEMA.SOMETABLE, TESTCOLB = value def
operation: UPDATE, on table "SCHEMA.SOMETABLE":
SCHEMA.SOMETABLE, TESTCOLA = value 789
SCHEMA.SOMETABLE, TESTCOLB = value ghi