wrapping esper with JRuby embrace

esper-jruby.rb

require 'rubygems'
require 'java'

require '../esper-4.2.0.jar'
require '../esper/lib/commons-logging-1.1.1.jar'
require '../esper/lib/antlr-runtime-3.2.jar'
require '../esper/lib/cglib-nodep-2.2.jar'
require '../esper/lib/log4j-1.2.16.jar'

include_class 'com.espertech.esper.client.EPRuntime'
include_class 'com.espertech.esper.client.EPServiceProviderManager'
include_class 'com.espertech.esper.client.EPServiceProvider'
include_class 'com.espertech.esper.client.EPStatement'

include_class 'com.espertech.esper.client.UpdateListener'
include_class 'com.espertech.esper.client.EventBean'
include_class 'org.apache.commons.logging.Log'
include_class 'org.apache.commons.logging.LogFactory'

require 'tweetstream'

java_import 'TweetEvent'

class TweetListener
  include UpdateListener

  def update(newEvents, oldEvents)
    newEvents.each do |event|
      puts "New event: #{event.getUnderlying.toString}"
    end
  end
end

epService = EPServiceProviderManager.getDefaultProvider
statement = epService.getEPAdministrator.createEPL("select * from TweetEvent")
statement.addListener(TweetListener.new)

TweetStream::Client.new('username','password').track('keyword') do |t|
  event = TweetEvent.new(t.user.screen_name, t.text, t.user.time_zone, t.retweet_count)
  epService.getEPRuntime.sendEvent(event);
end

TweetEvent.java

// A simple Tweet POJO:
// $> javac TweetEvent.java

public class TweetEvent {
    private String user;
    private String text;
    private String timezone;
    private int retweets;

    public TweetEvent(String user, String text, String timezone, int retweets) {
        this.user = user;
        this.text = text;
        this.timezone = timezone;
        this.retweets = retweets;
    }

    public int getRetweets() {
        return retweets;
    }

    public String getText() {
      return text;
    }

    public String getUser() {
      return user;
    }

    public String getTimezone() {
      return timezone;
    }

    public String toString() {
      return user + ": " + text + " - (" + timezone + ")";
    }
}