I went through the code in SVN last night. Here are few problems I have noticed.
* There is a "init" method which does lot of datasource related work. First of all having a init method in a OO code doesn't make sense. YES, IOC containers use this since they can't handle any thing else while doing constructor injection. But we shouldn't follow that. This code actually belong to a RegistryDatasource class, which should ideally implement java.sql.Datasource. Then we are clean. * There is a ConnectionFactory class which does a trick. Given a java.sql.Datasource or a DB URI it gives a java.sql.connection. However, when a DB URI is given it uses the DriverManager. Please read the Java doc. The connections you get have very different QoS properties. If I am a user I will assume the Registry nicely encapsulate all of that and give me a very reliable connectivity to the datasource, which is not the case. Another reason to have our own RegistryDatasource class. So that way we need one constructor; JDBCRegistry(DataSource dataSource) If what user has is a DB URI... he will, new JDBCRegistry( new RegistryDatasource(DB URI, ...) ) * The SecureRegistry doesn't completely encapsulate the Registry Right now the user has to construct a Registry and pass it to the SecureRegistry. The problem here is, there is insecure access to the same registry since the use build that externally. If we aggregate the Registry in to the SecureRegistry, an instance of a SecureRegistry is always secure. BTW, I was thinking about Paul's reason to have a JDBCRegistry class and a InMemory Registry class where he would like the developer to know what exactly he is going to get just looking at the class name (without reading the Javadoc). In that case how about naming them as, "PersistentRegistry" and "TransientRegistry"? /Sanjaya On Wednesday 05 December 2007, Chathura C. Ekanayake wrote: > Paul Fremantle wrote: > > Sanjaya has also persuaded me (on IM) that we should add another > > constructor > > > > new JDBCRegistry(DataSource dataSource) > > > > I'm not sure if there is an equivalent that uses a Connection as well. > > I think Sanjaya is proposing to have a DataSource implementation that > can wrap a Connection to handle this scenario. > So we need only one constructor to instantiate a registry with a > database connection (datasource or connection). > > Thanks, > Chathura > > > Paul > > > > Sanjiva Weerawarana wrote: > >> +1. > >> > >> Paul Fremantle wrote: > >>> I understand that we are using HSQLDB to provide the in-memory DB, > >>> its just a bit odd that the class is called JDBCRegistry. > >>> > >>> From a beginners perspective, wouldn't it make more sense to have > >>> another class called InMemoryRegistry. Of course under the covers it > >>> can use the JDBCRegistry with HSQLDB? > >>> > >>> I'm just trying to think of this from a beginning programmers > >>> perspective, and I'm not convinced everyone is going to > >>> automatically think of using a JDBCRegistry to do in-memory. > >>> > >>> So my preference would be: > >>> > >>> new InMemoryRegistry() > >>> new JDBCRegistry(String datasourceName) - Use the given data source. > >>> new JDBCRegistry(String driverClass, String URL, String userName, > >>> String password) - Use given connection URL to connect to the DB > >>> > >>> > >>> Paul > >>> > >>> Chathura C. Ekanayake wrote: > >>>> +1. So shall we remove "allowInMemoryDB" parameter from all > >>>> constructors and only start the in-memory database if the default > >>>> constructor is used. > >>>> > >>>> Then the constructors would look like: > >>>> > >>>> 1) JDBCRegistry() - Use in-memory DB. > >>>> > >>>> 2) JDBCRegistry(String datasourceName) - Use the given data source. > >>>> > >>>> 3) JDBCRegistry(String driverClass, String URL, String userName, > >>>> String password) - Use given connection URL to connect to the DB > >>>> > >>>> Thanks, > >>>> Chathura > >>>> > >>>> Paul Fremantle wrote: > >>>>> I'm bothered about the "fallback" to an inmemory database. I don't > >>>>> think that makes sense as something to do automatically. > >>>>> > >>>>> Surely its better for a user to explicitly try to start the > >>>>> JDBCReg and if that fails catch the exception or null and then > >>>>> create an in-mem Reg? > >>>>> > >>>>> Paul > >>>>> > >>>>> Sanjiva Weerawarana wrote: > >>>>>> +1 for 3 alternative constructors. Since the registry is unusable > >>>>>> until init'ed, IMO constructors make more sense. > >>>>>> > >>>>>> Thanks, > >>>>>> > >>>>>> Sanjiva. > >>>>>> > >>>>>> Chathura C. Ekanayake wrote: > >>>>>>> We want to allow users to configure registry database in > >>>>>>> different ways (e.g. using a data source, using a connection > >>>>>>> URL, specify whether to start in-memory database if other > >>>>>>> database is not available). > >>>>>>> > >>>>>>> So we provide few methods in the JDBCRegistry to configure them. > >>>>>>> We only want the registry to initialize after those parameters > >>>>>>> are configured. > >>>>>>> And we don't know whether the user is specifying them or not at > >>>>>>> the construction time. Therefore, user has to call init() after > >>>>>>> configuring them. > >>>>>>> > >>>>>>> Alternative would be to have 3 constructors. > >>>>>>> > >>>>>>> 1) JDBCRegistry() - Use default datasource name if available. If > >>>>>>> not available, use in-memory DB > >>>>>>> > >>>>>>> 2) JDBCRegistry(String datasourceName, boolean allowInMemoryDB) > >>>>>>> - Use given data source. If not available, use in-memory DB > >>>>>>> depending on the allowInMemoryDB parameter value > >>>>>>> > >>>>>>> 3) JDBCRegistry(String driverClass, String URL, String userName, > >>>>>>> String password, boolean allowInMemoryDB) - Use given connection > >>>>>>> URL to connect to the DB > >>>>>>> > >>>>>>> Thanks, > >>>>>>> Chathura > >>>>>>> > >>>>>>> Paul Fremantle wrote: > >>>>>>>> Chathura C. Ekanayake wrote: > >>>>>>>>> JDBCRegistry registry = new JDBCRegistry(); > >>>>>>>>> registry.init(); > >>>>>>>> > >>>>>>>> Love it! That's what I was looking for. > >>>>>>>> > >>>>>>>> Last question - why do we need init()? > >>>>>>>> > >>>>>>>> Paul > >>>>>>>> > >>>>>>>> _______________________________________________ > >>>>>>>> Registry-dev mailing list > >>>>>>>> [email protected] > >>>>>>>> http://wso2.org/cgi-bin/mailman/listinfo/registry-dev > >>>>>>> > >>>>>>> _______________________________________________ > >>>>>>> Registry-dev mailing list > >>>>>>> [email protected] > >>>>>>> http://wso2.org/cgi-bin/mailman/listinfo/registry-dev > >>>> > >>>> _______________________________________________ > >>>> Registry-dev mailing list > >>>> [email protected] > >>>> http://wso2.org/cgi-bin/mailman/listinfo/registry-dev > > _______________________________________________ > Registry-dev mailing list > [email protected] > http://wso2.org/cgi-bin/mailman/listinfo/registry-dev _______________________________________________ Registry-dev mailing list [email protected] http://wso2.org/cgi-bin/mailman/listinfo/registry-dev
