Logstash additional JARs

I'm trying to add a custom filter to Logstash 1.4.2, which is installed as a Debian package. The contrib plugins (http://logstash.net/docs/1.4.2/contrib-plugins) are also installed. This filter establishes a connection to an sqlite database, and for that it makes use of the JDBC sqlite driver:

require "logstash/filters/base"
require "logstash/namespace"
require "jdbc/sqlite3"
require "java"

class LogStash::Filters::MyFilter < LogStash::Filters::Base

  (...)

  public
  def register

    if @database.nil?
       raise "You must specify 'database => ...' in your filter"
    elsif not File.exists?(@database)
       raise "The database does not exist"
    end

    url = "jdbc:sqlite:" + @database

    Java::OrgSqlite::JDBC #initialize the driver
    @connection = java.sql.DriverManager.getConnection(url)

    @logger.info("Using database", :path => @database)

  end # def register

  (...)

end # class LogStash::Filters::MyFilter

However, when I try to start logstash I get the following error in the logs :

"cannot load Java class org.sqlite.JDBC"

I've tried to place the sqlite-jdbc-3.7.2.jar file provided by the contrib plugins into several locations, but so far I couldn't figure out what's the right one for JARs required by custom plugins, or whether it is a configuration issue.

Any ideas?

While I couldn't find the way of using external jars with Logstash 1.4, I could get it to work by replacing SQlite JDBC with Sequel, which is already included.

require "logstash/filters/base"
require "logstash/namespace"
require "sequel"

class LogStash::Filters::MyFilter < LogStash::Filters::Base

  (...)

  public
  def register

    if @database.nil?
       raise "You must specify 'database => ...' in your filter"
    elsif not File.exists?(@database)
       raise "The database does not exist"
    end

    @db = Sequel.connect("jdbc:sqlite:#{@database}")
    @logger.info("Using database", :path => @database)

  end # def register

  (...)

end # class LogStash::Filters::MyFilter