SessionFactory创建失败

今天在用Hibernate AnnotationConfiguration往数据库中写入数据时遇到一个bug,用junit测试时总是提示上述异常，

java.lang.ExceptionInInitializerError
    at com.hibernate.utils.HibernateUtil.(HibernateUtil.java:19)
    at com.hibernate.model.TeacherTest.launch(TeacherTest.java:21)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99)
    at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81)
    at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)
    at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75)
    at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45)
    at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:71)
    at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35)
    at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42)
    at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)
    at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.hibernate.HibernateException: 'hibernate.dialect' must be set when no Connection avalable
    at org.hibernate.dialect.resolver.DialectFactory.buildDialect(DialectFactory.java:107)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:138)
    at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2119)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2115)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1339)
    at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:867)
    at com.hibernate.utils.HibernateUtil.(HibernateUtil.java:13)
    ... 21 more

用debug跟踪时发现sessionFactory 获取不到，更别提获取Session了，因为以下的工具类是从 Annotation文档中直接copy过来，自认为应该不会有任何问题，但是问题就在这里~~~

public class HibernateUtil {

private static final SessionFactory sessionFactory;

    static {
        try {

            sessionFactory = new AnnotationConfiguration().buildSessionFactory();
//应该改为SessionFactory  sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
        } catch (Throwable ex) {
            // Log exception!
            System.out.println("SessionFactory创建失败，下面是失败的原因:");
            ex.printStackTrace();
            System.out.println("SessionFactory创建失败？");
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static Session getSession()
            throws HibernateException {
        return sessionFactory.openSession();
    }
}

在Console栏中提示SessionFactory创建失败，下面是失败的原因:

org.hibernate.HibernateException: 'hibernate.dialect' must be set when no Connection avalable

问题在于SessionFactory的获取上，我们以往用Configuration获取SessionFactory时是这样获取得：

SessionFactory  sessionFactory = new Configuration().configure().buildSessionFactory();

所以我们在用AnnotationConfiguration时也应该与之类似，即，而在文档中漏掉了configure（），导致我们获取不到sessionFavtory~~

这是文档中的小bug记得自己更正，希望能帮到你~~~

SessionFactory  sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();