org.hibernate.TransactionException: Transaction not

严重: Servlet.service() for servlet action threw exceptionorg.hibernate.TransactionException: Transaction not successfully started    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:100)    at com.jadecenter.filter.HibernateFilter.doFilter(HibernateFilter.java:34)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)    at com.jadecenter.filter.ChangeCharsetFilter.doFilter(ChangeCharsetFilter.java:28)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)    at java.lang.Thread.run(Unknown Source)

public void save(Project transientInstance) {        log.debug("saving Project instance");        [color=#FF0000]Transaction tran = getSession().beginTransaction();        try {            getSession().save(transientInstance);            getSession().flush();            tran.commit();            getSession().close();[/color]            log.debug("save successful");        } catch (RuntimeException re) {            log.error("save failed", re);            throw re;        }    }