All,

I am trying to configure Hibernate using Proxool but I am getting an error. My environment is on a linux box, hibernate 3.6.3, MySQL, hibernate-proxool-4*.jar and proxool-0.8.3.jar.

My hibernate.cfg.xml is as follows:



I keep getting the error:
java.lang.ClassNotFoundException: org.hibernate.service.jdbc.connections.spi.ConnectionProvider
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2818)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1159)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1647)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:192)
at org.hibernate.connection.ConnectionProviderFactory.initializeConnectionProviderFromConfig(ConnectionProviderFactory.java:174)
at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:102)
at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:84)
at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:459)
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:90)
at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2836)
at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2832)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843)
at com.ngc.mav.models.MAVHibernateDataManager.<init>(Unknown Source)
at com.ngc.mav.framework.AbstractMAVController.<clinit>(Unknown Source)
at com.ngc.mavadmin.MAVAdminControllerManager.registerControllers(MAVAdminControllerManager.java:18)
at com.ngc.mav.framework.AbstractMAVControllerManager.init(Unknown Source)
at com.ngc.mavadmin.MAVAdminApplication.init(MAVAdminApplication.java:20)
at com.vaadin.Application.start(Application.java:554)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.startApplication(AbstractApplicationServlet.java:1213)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:484)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:662)

or sometimes if I used (as someone mentioned on this message board):
<property name="hibernate.connection.provider_class">net.sf.hibernate.connection.ProxoolConnectionProvider</property>

I then get the error org.hibernate.HibernateException:Could not instantiate connection provider:net.sf.hibernate.connection.ProxoolConnectionProvider

It is probably something simple that I am missing. Thanks in advance.

Any particular reason you are using an older version of hibernate? There were signficant internal API changes from 3.6 to 4.0. Also, why use Proxool over c3p0? I believe c3p0 is a newer code base, whatever that's worth.

Hi imagenesis,
We are upgrading to Hibernate 4 soon.

I am looking into Proxool because c3p0 have been giving us fits. I would love to use c3p0 if I can find a solution to the exception that we get when redeploying our code in an eclipse enviroment. We get the following error using c3p0:

Exception in thread "Timer-5" java.lang.OutOfMemoryError: PermGen space.

Basically, we would make a code change in Eclipse and have it set up to "hot" redeploy our app automatically. After a few minutes of a few messages of Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread - #0" the #1, etc. our Tomcat server would just die and i would see on our console screen the fore-mentioned java.lang.OutOfMemoryError PermGen exception.

I must have searched the web for hours looking for a solution and the best I can find is to comment out the line in the c3p0 code: ThreadPoolAsynchronousRunner which was triggering the TimerTask. However, like someone mentioned, "Sometimes the cure is worst than the disease". I, also, tried to increase the JVM memory (i.e. -Xms512m -Xmx1024m), using the following options to launch apached: -XX:+CMSClassUnloadingEnabled -XX:CMSPerGenSweepingEnabled and it STILL did not solve the PermGen exception. It is so frustrating...hence I am looking into other open source connection pooling options.

If you know of a solution to my java.lang.OutOfMemoryError: PermGen space, that would be AWESOME! :)

Thanks.