持久性配置问题

我有一个Web应用程序（基于GWT / Vaadin），到目前为止我已经启动了

mvn jetty:run

现在我想在另一个Web服务器（也是Jetty）上运行它并获得数据库连接问题 .

在WAR文件中没有persistence.xml文件 . 这可能是失败的原因吗？

如果是，我应该如何配置持久性if

我正在使用Java DB（Derby），

b）Hibenate和

c）现在配置DB连接，如下所示

？

提前致谢

德米特里

private void tryToOpenSession(final String aConnectionString)
        throws Throwable {
    ...

    state = PersistenceState.OPENING_CONNECTION;
    final Configuration cnf = new Configuration();
    cnf.setProperty(Environment.DRIVER,
            "org.apache.derby.jdbc.EmbeddedDriver");
    cnf.setProperty(Environment.URL, aConnectionString);
    cnf.setProperty(Environment.DIALECT, DerbyDialect.class.getName());
    cnf.setProperty(Environment.SHOW_SQL, "true");
    cnf.setProperty(Environment.HBM2DDL_AUTO, "update");
    cnf.setProperty(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");

    cnf.addResource("persistence/Entity1.hbm.xml");
    cnf.addResource("persistence/Entity2.hbm.xml");
    ...
    cnf.addResource("persistence/EntityN.hbm.xml");

    sessionFactory = cnf.buildSessionFactory();

    session = getSession();

    ...

    state = PersistenceState.CONNECTION_OPEN;
}

UPD：这是例外：

java.lang.NoClassDefFoundError: Could not initialize class org.apache.derby.jdbc.EmbeddedDriver
    at java.lang.Class.forName0(Native Method) ~[na:1.6.0_20]
    at java.lang.Class.forName(Class.java:186) ~[na:1.6.0_20]
    at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:80) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:143) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:84) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:459) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:91) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2833) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2829) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1840) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]