JTA使用的问题

代码如下

UserTransaction tx=null;
		try {
			tx =(UserTransaction);new InitialContext();.lookup("java:comp/UserTransaction");;
			dao.addUser(user);;
			tx.commit();;

		} catch (Exception e); {
			if(tx!=null); 
				tx.rollback();;
			throw new Exception(e);;
			
		}

错误如下：

13:19:02,687 INFO  [STDOUT] session closed
13:19:05,859 INFO  [STDOUT] filter starts
13:19:06,125 INFO  [Environment] Hibernate 2.1 beta 5
13:19:06,156 INFO  [Environment] hibernate.properties not found
13:19:06,156 INFO  [Environment] using CGLIB reflection optimizer
13:19:06,171 INFO  [Configuration] Configuration resource: /hibernate.cfg.xml
13:19:06,421 INFO  [Configuration] Mapping resource: User.hbm.xml
13:19:06,703 INFO  [Binder] Mapping class: com.up.cip.po.User -> user
13:19:06,984 INFO  [Configuration] Configured SessionFactory: null
13:19:06,984 INFO  [Configuration] processing one-to-many association mappings
13:19:06,984 INFO  [Configuration] processing one-to-one association property re
ferences
13:19:06,984 INFO  [Configuration] processing foreign key constraints
13:19:07,046 INFO  [Dialect] Using dialect: net.sf.hibernate.dialect.MySQLDialec
t
13:19:07,046 INFO  [SettingsFactory] Use outer join fetching: true
13:19:07,093 INFO  [NamingHelper] JNDI InitialContext properties:{}
13:19:07,093 INFO  [DatasourceConnectionProvider] Using datasource: java:/mysqld
atasource
13:19:07,109 INFO  [TransactionFactoryFactory] Transaction strategy: net.sf.hibe
rnate.transaction.JTATransactionFactory
13:19:07,109 INFO  [NamingHelper] JNDI InitialContext properties:{}
13:19:07,125 INFO  [TransactionManagerLookupFactory] No TransactionManagerLookup
 configured (in JTA environment, use of process level read-write cache is not re
commended);
13:19:07,125 INFO  [TransactionManagerLookupFactory] No TransactionManagerLookup
 configured (in JTA environment, use of process level read-write cache is not re
commended);
13:19:07,390 INFO  [SettingsFactory] Use scrollable result sets: true
13:19:07,390 INFO  [SettingsFactory] JDBC 2 max batch size: 20
13:19:07,390 INFO  [SettingsFactory] echoing all SQL to stdout
13:19:07,390 INFO  [SettingsFactory] Query language substitutions: {}
13:19:07,390 INFO  [SettingsFactory] cache provider: net.sf.hibernate.cache.JCSC
acheProvider
13:19:07,406 INFO  [Configuration] instantiating and configuring caches
13:19:07,812 INFO  [SessionFactoryImpl] building session factory
13:19:08,421 INFO  [SessionFactoryObjectFactory] no JNDI name configured
13:19:08,609 ERROR [STDERR] java.lang.IllegalStateException: No transaction.
13:19:08,609 ERROR [STDERR]     at org.jboss.tm.TxManager.rollback(TxManager.jav
a:272);
13:19:08,609 ERROR [STDERR]     at org.jboss.tm.usertx.client.ServerVMClientUser
Transaction.rollback(ServerVMClientUserTransaction.java:134);

hibernate.cfg.xml如下：

<!DOCTYPE hibernate-configuration
    PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd">

<hibernate-configuration>
    <session-factory>
        <property name="connection.datasource">java:/mysqldatasource</property>
        <property name="show_sql">true</property>
        <property name="dialect">net.sf.hibernate.dialect.MySQLDialect</property>
        <property name="transaction.factory_class">net.sf.hibernate.transaction.JTATransactionFactory</property>
        <property name="jta.UserTransaction">java:comp/UserTransaction</property>
        <property name="hibernate.jdbc.batch_size">20</property>
			
        <!-- Mapping files -->
        <mapping resource="User.hbm.xml"/>
       
    </session-factory>

</hibernate-configuration>

如果把代码换成使用hibernate的session.beginTransaction()执行没有异常，但似乎是jdbc的事务控制。不知道是什么原因，我使用的是jboss。

tx.begin();  哪去了?

不好意思，低级错误，改了后就没有上述问题了。

我现在把代码改为如下：

 try { 
		 tx =(UserTransaction);new InitialContext();.lookup("java:comp/UserTransaction");; 
		 tx.begin();;
		 dao.addUser(user);; 
		 throw new Exception("haha");;	 

	  } catch (Exception e); { 
		 if(tx!=null); 
			tx.rollback();; 
		 throw new Exception(e);; 
          
	  }

照理应该会rollback的，但数据库表中却增加了一条记录，并没有rollback不知道是为什么？

为什么会这样啊？真奇怪啊！

dao中有session.flush()。我又试了一下，还是一样，调试日志中确定已经执行了rollback但没有将前面的数据库操作取消，为什么呢？

看到你用的是MySQLDialect，Mysql默认d的Table Type是不支持Transaction的，会不会是这个原因？

有可能，谢了，去试试看！！

没问题了，改成innodb的表就行了。