我有一个简单的类,它开始3个线程,并在每个线程中保存一个新对象。但是我遇到了我无法理解的例外。谁能帮我理解为什么会例外?
package test; import java.util.Date; import org.hibernate.Session; import domain.Event; import util.HibernateUtil; public class EventBeanTest { public static void main(String [] args) { Event e1 = new Event(); e1.setTitle("111"); e1.setDate(new Date()); Event e2 = new Event(); e2.setTitle("222"); e2.setDate(new Date()); Event e3 = new Event(); e3.setTitle("333"); e3.setDate(new Date()); Thread t1 = new Thread(new EventRunnable(e1)); Thread t2 = new Thread(new EventRunnable(e2)); Thread t3 = new Thread(new EventRunnable(e3)); t1.setName("event - 111"); t2.setName("event - 222"); t3.setName("event - 333"); t1.start(); t2.start(); t3.start(); } } class EventRunnable implements Runnable { private Event event; public EventRunnable(Event event) { this.event = event; } public void run() { System.out.println("Starting thread : " + Thread.currentThread().getName()); Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); session.saveOrUpdate(event); session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); System.out.println("Finishing thread : " + Thread.currentThread().getName()); } }
这是显示异常的日志文件的相关部分:
Hibernate: select max(EVENT_ID) from test.EVENTS Hibernate: insert into test.EVENTS (EVENT_DATE, TITLE, EVENT_ID) values (?, ?, ?) Hibernate: insert into test.EVENTS (EVENT_DATE, TITLE, EVENT_ID) values (?, ?, ?) Hibernate: insert into test.EVENTS (EVENT_DATE, TITLE, EVENT_ID) values (?, ?, ?) Apr 22, 2012 2:46:55 PM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop INFO: HHH000030: Cleaning up connection pool [jdbc:mysql://localhost:3306/test] Finishing thread : event - 333 Apr 22, 2012 2:46:55 PM org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction afterAfterCompletion INFO: HHH000425: Could not close session; swallowing exception[org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.stat.spi.StatisticsImplementor]] as transaction completed Exception in thread "event - 222" org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.stat.spi.StatisticsImplementor] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:126) at org.hibernate.internal.SessionFactoryImpl.getStatisticsImplementor(SessionFactoryImpl.java:1708) at org.hibernate.internal.SessionFactoryImpl.getStatistics(SessionFactoryImpl.java:1704) at org.hibernate.engine.transaction.internal.TransactionCoordinatorImpl.afterTransaction(TransactionCoordinatorImpl.java:140) at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.afterTransactionCompletion(JdbcTransaction.java:138) at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:184) at test.EventRunnable.run(EventBeanTest.java:60) at java.lang.Thread.run(Thread.java:722) Apr 22, 2012 2:46:55 PM org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction afterAfterCompletion INFO: HHH000425: Could not close session; swallowing exception[org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.stat.spi.StatisticsImplementor]] as transaction completed Exception in thread "event - 111" org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.stat.spi.StatisticsImplementor] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:126) at org.hibernate.internal.SessionFactoryImpl.getStatisticsImplementor(SessionFactoryImpl.java:1708) at org.hibernate.internal.SessionFactoryImpl.getStatistics(SessionFactoryImpl.java:1704) at org.hibernate.engine.transaction.internal.TransactionCoordinatorImpl.afterTransaction(TransactionCoordinatorImpl.java:140) at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.afterTransactionCompletion(JdbcTransaction.java:138) at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:184) at test.EventRunnable.run(EventBeanTest.java:60) at java.lang.Thread.run(Thread.java:722)
编辑1
<?xml version='1.0' encoding='utf-8'?> <session-factory> <!-- Database connection settings --> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/test</property> <property name="connection.username">vishnu</property> <property name="connection.password">con02305</property> <!-- JDBC connection pool (use the built-in) --> <property name="connection.pool_size">1</property> <!-- SQL dialect --> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property> <!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">true</property> <!-- Drop and re-create the database schema on startup <property name="hbm2ddl.auto">update</property> --> <property name="default_schema">test</property> <property name="show_sql">true</property> <mapping resource="domain/Event.hbm.xml"/> </session-factory>
Hibernate中的会话对象不是线程安全的,除非您同步访问会话对象,否则不应在不同线程中使用同一会话。