我可以在commit（）之后重用UserTransaction实例吗？

UserTransaction ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");  
ut.begin();  
doSomeWork();  
ut.commit();//Or rollback (I think it doesn't matter)  
ut.begin();   //Or rollback (I think it doesn't matter)  
doOtherWork();  
ut.commit();  

Reference atomikosUserTransactionFactoryDS = new Reference("com.atomikos.icatch.jta.UserTransactionImp", 
                "com.atomikos.icatch.jta.UserTransactionFactory", null);
atomikosUserTransactionFactoryDS.add(new RefAddr("name") {  
public Object getContent() {  
        return "UserTransaction";  
}});  
atomikosUserTransactionFactoryDS.add(new RefAddr("type") {  
    public Object getContent() {  
    return "com.atomikos.icatch.jta.UserTransactionImp";  
}});  
initContext.rebind("java:comp/UserTransaction", atomikosUserTransactionFactoryDS);