Spring 事务

 

Spring 事务不回滚的问题关键是：不能对该异常用try...catch处理，否则不会回滚事务！

 

@Service("systemConfigService")
public class SystemConfigServiceImpl extends AbstractGenericService<SystemConfig> implements SystemConfigService {
	
	@Resource(name="systemConfigDAO")
	private SystemConfigDAO systemConfigDAO;	
	
	@Override
	public void deleteByIds(String id) {
		if(id != null){
			String[] ids = id.split(",");
			try {
				SystemConfig systemConfig = systemConfigDAO.get(2);
				systemConfig.setValue("测试值");
				systemConfigDAO.update(systemConfig);
				
				// 执行如下操作，数据库将报唯一索引重复问题
				// Caused by: java.sql.BatchUpdateException: Duplicate entry 'PORTAL.CITYCODE' for key 'name'
				SystemConfig systemConfig2 = systemConfigDAO.get(2);
				systemConfig2.setName("PORTAL.CITYCODE");
				systemConfigDAO.update(systemConfig2);
			} 
			catch (Exception e) {
				log.error(e);
				// 如果注释掉throw new RuntimeException，那么事务将不能回滚，因为spring捕捉不到Exception
				// 解决办法，去掉try catch，或者在cache中抛出异常以便spring捕获
				throw new RuntimeException("运行时出错！"); 
			}
		}
	}
}

<aop:config proxy-target-class="true" /> <!--cglib事物-->

<tx:annotation-driven proxy-target-class="true" 
transaction-manager="transactionManager" /> 
@Transactional 必须使用tx:annotation-driven 开启注解事务支持

Connection conn ;  
try{  
     conn ＝ DriverManager.getConnection();//①获取数据连接  
     conn.setAutoCommit(false); //②关闭自动提交的机制  
     conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE); //③设置事务隔离级别  
  
     Statement stmt = conn.createStatement();   
      
     int rows = stmt.executeUpdate( "INSERT INTO t_topic VALUES(1,’tom’) " );  
     rows = stmt.executeUpdate( "UPDATE t_user set topic_nums = topic_nums +1 "+  
"WHERE user_id = 1");   
       
     conn.commit();//④提交事务  
}catch(Exception e){  
     …  
     conn.rollback();//⑤回滚事务  
}finally{  
   …  
}  

Statement stmt = conn.createStatement();   
int rows = stmt.executeUpdate( "INSERT INTO t_topic VALUES(1,’tom’)");  
  
Savepoint svpt = conn.setSavepoint("savePoint1");//①设置一个保存点  
rows = stmt.executeUpdate( "UPDATE t_user set topic_nums = topic_nums +1 "+  
          "WHERE user_id = 1");   
…  
//②回滚到①处的savePoint1，①之前的SQL操作，在整个事务提交后依然提交，  
//但①到②之间的SQL操作被撤销了  
conn.rollback(svpt);   
…  
conn.commit();//③提交事务