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From: Christian S. <Chr...@gm...> - 2005-04-02 09:06:36
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i've added a data import handler to retrieve data from http://www.onvista.de/. with onvista you cannot choose the stock exchange from which you want the data (for this purpose i added the MarketPlace called "UNDEFINED") nor do you get volume information. but you can get data for funds, which you cannot get from yahoo. i did not implement this yet, but you can get currency data aswell, here for example the EUR/USD values: http://waehrungen.onvista.de/kursliste.html?ID_CURRENCY_FROM=EUR&ID_CURRENCY_TO=USD&RANGE=3M it would be nice if i could get historical values for certificates, too. but currently onvista does not provide that :( while i was implementing the new data input handler i rewrote the caching subsystem from scratch. now the cached data looks the same no matter from which data input handler it is coming from. it is simply a dedicated java object structure serialized to xml. because of this change the import procedure now looks the same for any cached data, too! when i have an inheritance hierarchy like the hierarchy for subject: subject / | \ marketplace observer securitypaper / \ fund share and i want to retrieve an object from the database via castor as one of its base classes then i have the problem that the object is "truncated", that is the object is really of the baseclass type and none of its additional properties are available. i solved this problem now by adding a typeid property to the subject class and by adding a new method: subject = Functionality.downcastSubject(subject); via this additional call you ensure that the returned subject is the correct java type with all of its additional properties available. my next implementation plans are to - implement currencies - db structures - retrieval of values from onvista - conversion of values for security papers to and from given currencies - restructure the Functionality "namespace" class. - only methods with proper java types, no methods that only take strings - methods should always handle exceptions by throwing exceptions not by returning special return values - move the current methods that were meant to facilitate the integration of the functionality into sisc to another "namespace" class called Scheme or similar. - finish the implementation of portfolios and its evaluation methods. -- Christian Schuhegger http://www.el-chef.de/ |