Hibernate 4——配置C3P0

Question

除非我真的很沮丧，否则我不会发布这个。我正在尝试在一个非常简单的应用程序中使用 Hibernate 4.1.1 配置 C3P0，但我收到了一个找不到类的异常。我在我的类路径中包含了 C3P0 特定的 jar 文件。 hibernate-c3p0-3.5.2-Final.jar

hibernate.properties:

hibernate.connection.provider_class=org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
hibernate.c3p0.acquire_increment=1
hibernate.c3p0.idle_test_period=180
hibernate.c3p0.max_size=60
hibernate.c3p0.max_statements=0
hibernate.c3p0.min_size=10

堆栈跟踪:

28 Jul, 2012 9:23:08 PM org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator instantiateExplicitConnectionProvider
INFO: HHH000130: Instantiating explicit connection provider: org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
Exception in thread "main" org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.service.jdbc.connections.spi.ConnectionProvider]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:186)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:150)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:223)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:89)
    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:2277)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2273)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1742)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1782)
    at eko.test.hibernate.Hibernate4Test.main(Hibernate4Test.java:17)
Caused by: org.hibernate.HibernateException: Could not instantiate connection provider [org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider]
    at org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator.instantiateExplicitConnectionProvider(ConnectionProviderInitiator.java:192)
    at org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator.initiateService(ConnectionProviderInitiator.java:114)
    at org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator.initiateService(ConnectionProviderInitiator.java:54)
    at org.hibernate.service.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:69)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:176)
    ... 13 more
Caused by: org.hibernate.service.classloading.spi.ClassLoadingException: Unable to load class [org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider]
    at org.hibernate.service.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:141)
    at org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator.instantiateExplicitConnectionProvider(ConnectionProviderInitiator.java:189)
    ... 17 more
Caused by: java.lang.ClassNotFoundException: Could not load requested class : org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
    at org.hibernate.service.classloading.internal.ClassLoaderServiceImpl$1.findClass(ClassLoaderServiceImpl.java:99)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at org.hibernate.service.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:138)
    ... 18 more

Answer 1

您包含的 jar 文件的版本为 3.5.2-Final，并且不包含您配置的类。为什么不使用版本为 4.1.1 的(因为这是您使用的 Hibernate 版本)，并且里面有必要的类:http://grepcode.com/snapshot/repository.jboss.org/nexus/content/repositories/releases/org.hibernate/hibernate-c3p0/4.1.1.Final/