Kommons: reusable objects for j2me

Antonio Terreno

Mobile DevelopmentFluidtime DataServices GmbH

info@java2me.orghttp://kommons.java2me.org/

Long-term Goal● To have a collection of J2ME classes

– Stable– Easy to use, to integrate– Tested (j2meunit)– Open– Well coded

Kommons logging● Logger “like” log4j

– Appenders● Console● Bluetooth● Http

– Debugging levels● Enabled/Disabled● Debug level● Info level

– Easy to use● Perfect integration with Log4E

Kommons loggingprivate final static Logger logger =

Logger.getLogger("LoggerExampleMIDlet");

protected void startApp() { logger.addAppender(AppenderType.CONSOLE); logger.addAppender(AppenderType.PHONE); logger.setDebugEnabled(true);

if (logger.isDebugEnabled()) { logger.debug("startApp() - start"); }

initDisplay();

Midp Worker● Before/After pattern simple implementation

public abstract class MIDPWorker extends TimerTask

public final void run() { before();

try { doWork(); } catch (LogicalException e) { doCatch(e); } finally { after();

ISO helpers● IsoDate Helper

– IsoDate parser for ISO 8601 format– http://www.w3.org/TR/xmlschema-2/#date–

● IsoDuration Helper– IsoDuration parser for ISO 8601 format.– http://www.w3.org/TR/xmlschema-2/#duration– IsoDuration format is (-)PnYnMnDTnHnMnS

ISO helpers● IsoDate Helper

– IsoDate parser for ISO 8601 format– http://www.w3.org/TR/xmlschema-2/#date–

● IsoDuration Helper– IsoDuration parser for ISO 8601 format.– http://www.w3.org/TR/xmlschema-2/#duration– IsoDuration format is (-)PnYnMnDTnHnMnS

I/O● Bluetooth

– A simple send & receive client● Needs your help! :-)● Integration with BtFree??? Federico Paparoni???

● HTTP– A complete http client (post/get)– URL encoding– Cookie auth supported– Easy parameters use

Http example try { String xml = XMLAdapter.getInstance().toXML(msg); logger.debug("Posting", xml); xml = HttpClient.URLencode(xml);

HttpClient httpClient = new HttpClient(); String[][] params = { { "sXmlMobileRequest", xml }, { "userName", UserPropertiesWrapper.currentUser() }, };

String response = httpClient.post(Fluidtime.ENDPOINT + "TimeWindow/update.action", params);

msg = (Message) XMLAdapter.getInstance().fromXML(response); } catch (LogicalException e) { logger.debug(e);

The cache● A persistence cache for MIDP 2.0

– save(PersistentObject e)– delete(PersistentObject e)– PersistentObject find(String id)– reset()– boolean isEmpty()

RMS-xml cache● Runtime cache:

– An hash table containing objects● Shutting down?

– Storing objects in xml format● Starting up?

– Retrive of the objects from the rms

Problems● How to retrive the objects in cache?

– EntityRecordMapping idea– It contains the reference from an Entity id and

Its Record Store Id

● How to find an object?● 1. in the runtime cache● 2. in the rms● 3. if found it will be putted on the cache & used

RMS-xml cache

RMSE.R.mapping

Cache

Model

Benefits● Possibility to store any kind of object● Possibility to store collection of objects

Next Steps of Action● Involve developers● Merge other interesting project into ● Javadoc● Website● Licence● Junit testing● Receive feedbacks● ...

Credits to● Alberto Lagna (CTO Fluidtime GmbH)● Jean-Marie Dautelle (Javolution.org)● Fluidtime GmbH● Java2me.org forum :-)● Jmdf of course!

Q&A● Questions? Suggestions?