Question

我做错了什么？

我的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="Test" transaction-type="RESOURCE_LOCAL">
           <provider>org.hibernate.ejb.HibernatePersistence</provider>
           <class>User</class>
            <properties>
              <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
              <property name="hibernate.connection.url" value="jdbc:hsqldb:mem:test"/>
              <property name="hibernate.connection.password" value="sa"/>
              <property name="hibernate.connection.username" value=""/>
              <property name="hibernate.hbm2ddl.auto" value="create"/>
              <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
              <property name="hibernate.show_sql" value="true"/>
              <property name="hibernate.format_sql" value="true"/>
            </properties>
          </persistence-unit>

我的代码

...
Persistence.createEntityManagerFactory("Test")
...

我收到此错误

javax.persistence.PersistenceException: [PersistenceUnit: Test] Unable to build EntityManagerFactory
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:915)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:890)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:57)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)
    at com.aol.biz.vendor.persistence.TestVpsUser.setUp(TestVpsUser.java:32)
    at junit.framework.TestCase.runBare(TestCase.java:125)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected(TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:118)
    at junit.framework.TestSuite.runTest(TestSuite.java:208)
    at junit.framework.TestSuite.run(TestSuite.java:203)
    at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.hibernate.HibernateException: Connection cannot be null when 'hibernate.dialect' not set
    at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:97)
    at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:67)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:170)
    at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:71)
    at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2274)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2270)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1739)
    at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:93)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:905)
    ... 18 more

BUT !!

如果我在创建工厂之前手动加载了jdbc驱动程序类 - 一切正常。 O_O

try {
            Class.forName("org.hsqldb.jdbcDriver");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

如果没有这一步，我怎么能这样做？ Plz帮助！

Answer 1

我有4.1.2.Final的类似问题。但如果我回到4.1.1.Final，我的程序运行正常。

Hibernate 4.1.2 HHH000342：无法获取与查询元数据的连接：找不到适合jdbc的驱动程序：hsqldb：mem：test

1 个答案: