Question

以下persistence.xml在Maven项目（JAR打包）的JUnit测试中使用时有效：

<?xml version="1.0" encoding="UTF-8" ?>
<persistence 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_1_0.xsd"
    version="1.0">

    <persistence-unit name="test">
        <class>be.test.site.model.User</class>
        <class>be.test.site.model.SignIn</class>

        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/test?useServerPrepStmts=false" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="root" />

            <property name="hibernate.hbm2ddl.auto" value="create" />
        </properties>
    </persistence-unit>
</persistence>

使用的代码是：

EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("test");

当我在WAR（persistence.xml）中部署这个相同的/WEB-INF/classes/META-INF/persistence.xml时，JBoss AS 7.1.1给了我：

21:36:49,270 INFO  [org.jboss.as.jpa] (MSC service thread 1-8) JBAS011401: Read persistence.xml for test
21:36:49,559 INFO  [org.jboss.as.connector.deployers.jdbc] (MSC service thread 1-5) JBAS010404: Deploying non-JDBC-compliant driver class com.mysql.jdbc.Driver (version 5.1)
21:36:49,599 INFO  [org.jboss.as.jpa] (MSC service thread 1-1) JBAS011402: Starting Persistence Unit Service 'webapp.war#test'
21:36:49,748 INFO  [org.hibernate.annotations.common.Version] (MSC service thread 1-1) HCANN000001: Hibernate Commons Annotations {4.0.1.Final}
21:36:49,754 INFO  [org.hibernate.Version] (MSC service thread 1-1) HHH000412: Hibernate Core {4.0.1.Final}
21:36:49,755 INFO  [org.hibernate.cfg.Environment] (MSC service thread 1-1) HHH000206: hibernate.properties not found
21:36:49,757 INFO  [org.hibernate.cfg.Environment] (MSC service thread 1-1) HHH000021: Bytecode provider name : javassist
21:36:49,778 INFO  [org.hibernate.ejb.Ejb3Configuration] (MSC service thread 1-1) HHH000204: Processing PersistenceUnitInfo [
    name: test
    ...]
21:36:50,083 WARN  [org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator] (MSC service thread 1-1) HHH000181: No appropriate connection provider encountered, assuming application will be supplying connections
21:36:50,103 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-1) MSC00001: Failed to start service jboss.persistenceunit."webapp.war#test": org.jboss.msc.service.StartException in service jboss.persistenceunit."webapp.war#test": Failed to start service
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1767) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) [rt.jar:1.7.0]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) [rt.jar:1.7.0]
    at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to build EntityManagerFactory
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:914)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:889)
    at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:73)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:162)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.start(PersistenceUnitServiceImpl.java:85)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
    ... 3 more
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:176)
    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:2270)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2266)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1735)
    at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:84)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904)
    ... 9 more

编辑：它在Apache Tomcat 7.0.30中运行良好。

Answer 1

我遇到了同样的问题，我的本地数据库已损坏，我的数据库的本地服务器已停止。我不得不重新启动数据库服务器。

Answer 2

同样有问题（使用maven和jboss），由于某种原因，eclipse（或其他东西）在一个maven项目中生成了一个基本上空的persitence.xml。只需删除它。

JBoss AS 7：persistence.xml给出“当'hibernate.dialect'没有设置时，连接不能为空”

2 个答案: