求救？？？org.hibernate.TransactionException: Transaction not successfully started
在学习Hibernate
有个car的数据库，只有一个表basiccar
四个字段：
id，name，factory，date
我编写了POJO文件，也映射了，也写了Hibernate配置文件
POJO：

Java code

package basicCar.bean;import java.util.Date;public class BasicCar implements java.io.Serializable{    private long id;    private String name;    private String factory;    private Date date;    public BasicCar(){            }    public BasicCar(String name,String factory,Date date){        this.name = name;        this.factory = factory;        this.date = date;    }    public long getId() {        return id;    }    public void setId(long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getFactory() {        return factory;    }    public void setFactory(String factory) {        this.factory = factory;    }    public Date getDate() {        return date;    }    public void setDate(Date date) {        this.date = date;    }    }

映射文件：

XML code

<hibernate-mapping><class name="basicCar.bean.BasicCar" table="basiccar">    <id        name="id"        type="long"        column="id"    >        <generator class="increment" />    </id>    <property name="name" type="java.lang.String" column="name" />    <property name="factory" type="java.lang.String" column="factory" />    <property name="date" type="date" column="date" />    </class></hibernate-mapping>

Hibernate；

XML code

<hibernate-configuration>    <session-factory>        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>        <property name="connection.username">root</property>        <property name="connection.password">1119</property>         <property name="connection.url">jdbc:mysql://localhost:3306/car</property>        <property name="show_sql">true</property>                <mapping resource="basicCar/bean/BasicCar.hbm.xml" />    </session-factory></hibernate-configuration>

util：

Java code

package com.chuanjie56.util;import org.hibernate.HibernateException;import org.hibernate.Session;import org.hibernate.cfg.Configuration;public class HibernateSessionFactory {    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";    @SuppressWarnings("unchecked")    private static final ThreadLocal threadLocal = new ThreadLocal();    private static final Configuration cfg = new Configuration();    private static org.hibernate.SessionFactory sessionFactory;    @SuppressWarnings("unchecked")    public static Session currentSession() throws HibernateException {        Session session = (Session) threadLocal.get();        if (session == null) {            if (sessionFactory == null) {                try {                    cfg.configure(CONFIG_FILE_LOCATION);                    sessionFactory = cfg.buildSessionFactory();                }                catch (Exception e) {                    System.err.println("%%%% Error Creating SessionFactory %%%%");                    e.printStackTrace();                }            }            session = sessionFactory.openSession();            threadLocal.set(session);        }        return session;    }    @SuppressWarnings("unchecked")    public static void closeSession() throws HibernateException {        Session session = (Session) threadLocal.get();        threadLocal.set(null);        if (table>    
 

测试文件；

Java code

 
 public class Test { 
  
 /** 
  * @param args 
  */ 
 public static void main(String[] args) { 
 // TODO Auto-generated method stub 
 Test test = new Test(); 
 //test.saveEntity(); 
 test.updateEntiry(); 
 //test.deleteEntity(); 
 } 
  
 void saveEntity(){ 
 Session session=null; 
 Transaction tx = null; 
 session = HibernateSessionFactory.currentSession(); 
 tx = session.beginTransaction(); 
 BasicCar bc = new BasicCar(); 
 bc.setFactory("Beijing123"); 
 bc.setName("BJcar123"); 
 bc.setDate(Date.valueOf("1966-02-03")); 
 session.save(bc); 
 tx.commit(); 
 } 
 void deleteEntity(){ 
 Session session=null; 
 Transaction tx = null; 
 try{ 
 session = HibernateSessionFactory.currentSession(); 
 tx = session.beginTransaction(); 
 BasicCar bc = (BasicCar)session.load(BasicCar.class, new Long(1)); 
 session.delete(bc); 
 tx.commit(); 
 }catch(HibernateException e){ 
 throw e; 
 }finally{ 
 if(tx!=null) 
 tx.rollback(); 
 HibernateSessionFactory.closeSession(); 
 } 
 } 
 void updateEntiry(){ 
 Session session=null; 
 Transaction tx = null; 
 try{ 
 session = HibernateSessionFactory.currentSession(); 
 tx = session.beginTransaction(); 
 BasicCar bc = (BasicCar)session.load(BasicCar.class, new Long(2)); 
 bc.setName("shCar"); 
 bc.setFactory("SH00"); 
 session.update(bc); 
 tx.commit(); 
 }catch(HibernateException e){ 
 throw e; 
 }finally{ 
 if(tx!=null) 
 tx.rollback(); 
 HibernateSessionFactory.closeSession(); 
 } 
 } 
 void queryEntity(){ 
 Session session=null; 
 try{ 
 session = HibernateSessionFactory.currentSession(); 
 Query query = session.createQuery("from BasicCar"); 
 BasicCar bc = (BasicCar)query.list().get(0); 
 System.out.println("query:"+bc.getName()); 
 }catch(Exception e){ 
  
 } 
 } 
 } 
 

增加，查询操作没问题，
但是删除和更新操作报异常：
Exception in thread "main" org.hibernate.TransactionException: Transaction not successfully started
at org.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:183)
at basicCar.Test.updateEntiry(Test.java:76)
at basicCar.Test.main(Test.java:27)


不知道为什么




[解决办法]
if(tx!=null)
tx.rollback();
放在catch块里,别放在finlly块里,这样每次必然执行,不出错才怪了
[解决办法]
tx.commit(); 后在执行tx.rollback()是没有效果的。
[解决办法]
结帖散分啊
[解决办法]
恭喜问题已经解决了，注意程序逻辑。
[解决办法]
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