Oh Sorry Debashish I see that you're working with Google App Engine. I've worked with Google Web Toolkit and Hibernate for standalone applications, not applications that are deployed on Google App Engine. The link that you sent me is for Google Web Toolkit + Hibernate. I imagine that Google App Engine has restrictions on the classes that you can use, in this case java.net.Socket. I think, and again I'm no expert on GAE, that you can't use any database you want, you have to use the database that the GAE documentation describes. If it's something like BigTable, I don't know if you can use Hibernate on top of that. I think that I read an article on using Java Persistant Architecture, which is an abstraction of what Hibernate does, with GAE.
Regards, Néstor Boscán On Tue, Feb 8, 2011 at 9:31 AM, Debashish <[email protected]> wrote: > Hi Néstor, > > I have followed all the steps which required a Hibernate application > to work. > And this sample hibernate module is working fine without GWT as UI. > > However while connecting to any Database we need to put Driver class > in the classpath and > hibernate also requires the Classes12.jar or ojdbc14.jar at it's > classpath. > This is required so that it can understand the driver property placed > in hibernate.cfg.xml file > <property > name="connection.driver_class">oracle.jdbc.driver.OracleDriver</ > property> > > And probaly this class is not allowed in Google APP and I am getting > an error as > --------------- > Caused by: java.lang.NoClassDefFoundError: java.net.Socket is a > restricted class. Please see the Google App Engine > developer's guide for more details. > --------------- > > *** This is the local database in my case and I am absolutely getting > no way to resolve it. > > Please sugggest me if any other approach / websites to follow for > this. > > Thanks > Debashish > > On Feb 6, 1:55 am, Néstor Boscán <[email protected]> wrote: > > Hi > > > > I checked the link that you sent and this is will work of course but you > > will have to create a lot of DTO objects for your application and map the > > POJO objects from Hibernate to the DTO which will require a lot of > coding. > > The example should work, your DTOs should be serialized, Now what I don't > > understand is that if you're using Hibernate why use JDBC directly?. You > can > > get a Connection to your database from the Session object or create an a > > SQLQuery. From what I'm reading it looks like you're using > java.net.Socket > > on the GWT Client side and this is not a valid class. > > > > Regards, > > > > Néstor Boscán > > > > > > > > On Sat, Feb 5, 2011 at 2:52 PM, Debashish <[email protected]> > wrote: > > > Hi Néstor, > > > > > Thank you for the response regarding the Hibernate with GWT. > > > > > However I have followed the similar approach given in the below link > > > > > > http://code.google.com/webtoolkit/articles/using_gwt_with_hibernate.html > > > which suggets to use DTO approach to map the hibernate domain object > > > to DTO > > > and passed to the data to GWT layer. > > > > > I have a query on the Local Database connectivity from GWT. Is it > > > possible to make a > > > JDBC call(using Oracle Thin Driver). I have tried a normal jdbc > > > connection from GWT > > > using classes12.jar file in classpath and using > > > Class.forName("Oracle.jdbc.driver.OracleDriver"). > > > I have deployed on Google Apps server. > > > > > I am getting the below error message while while running the > > > application. > > > > > > ---------------------------------------------------------------------------------------------------------------------- > > > java.net.Socket is a restricted class. Please see the Google App > > > Engine developer's guide for more details. > > > [ERROR] javax.servlet.ServletContext log: Exception while dispatching > > > incoming RPC call > > > com.google.gwt.user.server.rpc.UnexpectedException: Service method > > > 'public abstract java.lang.Long > > > > > > com.google.musicstore.client.MusicStoreService.saveAccount(com.google.music > > > store.client.dto.AccountDTO)' > > > threw an unexpected exception: java.lang.ExceptionInInitializerError > > > at > > > com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java: > > > 378) > > > > > > --------------------------------------------------------------------------------------------------------------------- > > > > > Could you please suggest me of any good links or site which provides > > > an approach to develope GWT aplications > > > using local database. > > > > > Thanks > > > Dev > > > > > On Jan 26, 5:20 pm, Néstor Boscán <[email protected]> wrote: > > > > This is very tipical in Hibernate applications that have to serialize > > > > objects through the network be it GWT, Web Services, JSON, etc. > Hibernate > > > > will leave his own POJO in your objects for lazy initialization > purposes. > > > > When GWT or a Web Service tries to serialize the objects and opens > the > > > > hibernate POJO it will throw LazyInitializationException because the > > > > connection is already closed. What I've done in my applications is to > > > clean > > > > the POJO of any Hibernate references. This is done with a Hibernate > > > Cleaner > > > > class. On the web there are a couple of examples of this. > > > > > > Regards, > > > > > > Néstor Boscán > > > > > > On Tue, Jan 25, 2011 at 2:33 PM, Debashish <[email protected]> > > > wrote: > > > > > Hi > > > > > > > I am trying for a sample using GWT and database layer as Hibernate > > > > > with Oracle on Google Aps server. > > > > > > > I have done a sample for Hibernate with JSP as presentation layer, > > > > > which is working fine. > > > > > But the same approach is not working with GWT. > > > > > > > Here is a verygood link on this topic > > > > > > http://code.google.com/webtoolkit/articles/using_gwt_with_hibernate.html > > > > > and my approach is almost similar. > > > > > > > I have followed the below approach, > > > > > The RemoteServiceServlet makes a call to Hibernate layer and tries > the > > > > > initializes the SessionFactory as below, > > > > > sessionFactory = new > > > > > Configuration().configure().buildSessionFactory(); > > > > > > > I have added the jars necessary for the Hibernate layer (and > > > > > classes12.jar for oracle driver). > > > > > > > However while running , it is giving me an error as below, > > > > > > -------------------------------------------------------------------------------------------------------- > > > > > Initial SessionFactory creation > failed.java.lang.NoClassDefFoundError: > > > > > java.net.Socket is a restricted class. Please see the Google App > > > > > Engine developer's guide for more details. > > > > > [ERROR] javax.servlet.ServletContext log: Exception while > dispatching > > > > > incoming RPC call > > > > > com.google.gwt.user.server.rpc.UnexpectedException: Service method > > > > > 'public abstract java.lang.Long > > > > > > com.google.musicstore.client.MusicStoreService.saveAccount(com.google.musicstore.client.dto.AccountDTO)' > > > > > threw an unexpected exception: > java.lang.ExceptionInInitializerError > > > > > at > > > > > > com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java: > > > > > 378) > > > > > > -------------------------------------------------------------------------------------------------------- > > > > > I have one through some of the threads which suggested me to > download > > > > > the google apps jar files and try it. I have downladed it. but > there > > > > > is no proper direction on how to make use of which jar file. > > > > > > > Have anybody tried the same. Please let me know if anything I am > doing > > > > > wrong. > > > > > *** Note that I am using Oracle 9.2 as local database. > > > > > > > Thanks > > > > > Dev > > > > > > > -- > > > > > You received this message because you are subscribed to the Google > > > Groups > > > > > "Google Web Toolkit" group. > > > > > To post to this group, send email to > > > [email protected]. > > > > > To unsubscribe from this group, send email to > > > > > [email protected]<google-web-toolkit%[email protected]> > <google-web-toolkit%2Bunsubs[email protected]> > > > <google-web-toolkit%2Bunsubs[email protected]> > > > > > . > > > > > For more options, visit this group at > > > > >http://groups.google.com/group/google-web-toolkit?hl=en.-Hidequoted > > > text - > > > > > > - Show quoted text - > > > > > -- > > > You received this message because you are subscribed to the Google > Groups > > > "Google Web Toolkit" group. > > > To post to this group, send email to > [email protected]. > > > To unsubscribe from this group, send email to > > > [email protected]<google-web-toolkit%[email protected]> > <google-web-toolkit%2Bunsubs[email protected]> > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/google-web-toolkit?hl=en.- Hide quoted > text - > > > > - Show quoted text - > > -- > You received this message because you are subscribed to the Google Groups > "Google Web Toolkit" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-web-toolkit%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-web-toolkit?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. 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