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Event Stream Intelligence: Esper & NEsper

Getting Help

How to get support

  • Please contact EsperTech for support, training and services for Esper.
  • Consider the solution patterns page on this site.
  • Consider checking the regression test suite for specific questions, see Source Repository, under folder "src/test/java/com/espertech/esper/regression"
  • File an issue using JIRA.
  • Use the user mailing list for usage-related questions user@esper.codehaus.org.
  • File a feature request, also through JIRA.
  • Look through the mailing list archives.

When contacting us, please provide

  • The version used.
  • The complete stack trace of any exception, if an exception is reported.
  • A snippet of Java code or a unit test to reproduce the issue or question. Keep this code very simple and minimal without any additional classes, in the style of our regression test suite. Remove all random-ness from this test class. We have an example of a test case below.

Please consider obtaining support from EsperTech.

When we get questions on the mailing lists that ask for a complete solution, we can often only provide short summarized answers as we don't usually have the time to look into each inquiry in the detail required. EsperTech support will spend the time needed to get you to a desired solution.

Sample code snippet for providing a test

  • Simple event class "Event" with a single field is part of the test class.
  • Time controlled via external timer events and not Thread.sleep
  • Exception handling not cluttering the test code
    public class TestExample extends TestCase {

    private static final String DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS";

    public void testExample() throws Exception {
        Configuration config = new Configuration();
        config.getEngineDefaults().getThreading().setInternalTimerEnabled(false);
        config.addEventType(Event.class);
        EPServiceProvider engine = EPServiceProviderManager.getDefaultProvider(config);

        // set the current time
        engine.getEPRuntime().sendEvent(new CurrentTimeEvent(parse("2001-05-1T08:20:00.000")));

        // put your EPL statements here
        String epl = "create variable boolean IsOutputTriggered_1 = false;" +
                "\n" +
                "select * from EventsWindow output snapshot when count_insert > 1;";
        engine.getEPAdministrator().getDeploymentAdmin().parseDeploy(epl);

        engine.getEPAdministrator().getStatement("out").addListener(new PrintUpdateListener());

        // send sample events
        System.out.println("Sending P1");
        engine.getEPRuntime().sendEvent(new Event("P1"));

        // advance time
        engine.getEPRuntime().sendEvent(new CurrentTimeEvent(parse("2001-05-1T08:20:01.000")));

        // send sample events
        System.out.println("Sending P2");
        engine.getEPRuntime().sendEvent(new Event("P2"));
    }

    public static long parse(String datestr) {
        try {
            SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
            return sdf.parse(datestr).getTime();

        }
        catch (Exception ex) {
            throw new RuntimeException("Error parsing date '" + datestr + "' as format '" + DATE_FORMAT + "' : " + ex.getMessage(), ex);
        }
    }

    public static class Event {
        private String productId;

        public Event(String productId) {
            this.productId = productId;
        }

        public String getProductId() {
            return productId;
        }
    }
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