ComboPooledDataSource causes Hibernate 3 to reject JDBC < 4 drivers

[Stephane Epardaud]

When using Play 1.1 nighly r906 with a legacy DB driver (JDBC 3), Hibernate crashes when setting up the configuration with errors like the following:

Internal Server Error (500) for request GET /

Oops: AbstractMethodError
An unexpected error occured caused by exception AbstractMethodError: solid.jdbc.SolidDatabaseMetaData.getJDBCMajorVersion()I

play.exceptions.UnexpectedException: Unexpected Error
        at play.Invoker$Invocation.onException(Invoker.java:142)
        at play.Invoker$Invocation.run(Invoker.java:182)
        at Invocation.HTTP Request(Play!)
Caused by: java.lang.AbstractMethodError: solid.jdbc.SolidDatabaseMetaData.getJDBCMajorVersion()I
        at com.mchange.v2.c3p0.impl.NewProxyDatabaseMetaData.getJDBCMajorVersion(NewProxyDatabaseMetaData.java:3726)
        at org.hibernate.engine.jdbc.JdbcSupportLoader.useContextualLobCreation(JdbcSupportLoader.java:78)
        at org.hibernate.engine.jdbc.JdbcSupportLoader.loadJdbcSupport(JdbcSupportLoader.java:52)
        at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:121)
        at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2163)
        at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2159)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1383)
        at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:954)
        at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:883)
        at play.db.jpa.JPAPlugin.onApplicationStart(JPAPlugin.java:173)
        at play.Play.start(Play.java:381)
        at play.Play.detectChanges(Play.java:479)
        at play.Invoker$Invocation.init(Invoker.java:98)
        ... 1 more

By looking at the Hibernate code, it seems they handle NoSuchMethodException when accessing JDBC4 features, but because Play is using com.mchange.v2.c3p0.ComboPooledDataSource, we end up with a proxy in the middle which throws AbstractMethodError instead, thus confusing Hibernate. I'm not sure if this is a Play, Hibernate or c3p0 bug, but it prevents us from using Play, with versions of Hibernate that work in other frameworks (Seam, without that c3p0 probably).