(代码例子)spring基于注解AOP实现事务控制

pom.xml:

    
        org.springframework
        spring-context
        5.0.2.RELEASE
    
    
        org.springframework
        spring-test
        5.0.2.RELEASE
    
    
        commons-dbutils
        commons-dbutils
        1.4
    

    
        mysql
        mysql-connector-java
        5.1.6
    

    
        c3p0
        c3p0
        0.9.1.2
    

    
        junit
        junit
        4.12
    
    
        org.aspectj
        aspectjweaver
        1.8.7
    

 

 

bean.xml:

 

ConnectionUtils:

/**
 * 连接的工具类，它用于从数据源中获取一个连接，并且实现和线程的绑定
 */
@Component("connectionUtils")
public class ConnectionUtils {

    private ThreadLocal tl = new ThreadLocal();

    @Autowired
    private DataSource dataSource;


    /**
     * 获取当前线程上的连接
     * @return
     */
    public Connection getThreadConnection() {
        try{
            //1.先从ThreadLocal上获取
            Connection conn = tl.get();
            //2.判断当前线程上是否有连接
            if (conn == null) {
                //3.从数据源中获取一个连接，并且存入ThreadLocal中
                conn = dataSource.getConnection();
                tl.set(conn);
            }
            //4.返回当前线程上的连接
            return conn;
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    /**
     * 把连接和线程解绑
     */
    public void removeConnection(){
        tl.remove();
    }
}

AccountDaoImpl:

/**
 * 账户的持久层实现类
 */
@Repository("accountDao")
public class AccountDaoImpl implements IAccountDao {

    @Autowired
    private QueryRunner runner;

    @Autowired
    private ConnectionUtils connectionUtils;


    @Override
    public List findAllAccount() {
        try{                    
            return runner.query(connectionUtils.getThreadConnection(),"select * from account",new BeanListHandler(Account.class));
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

....

 

AccountServiceImpl:

@Service("accountService")
public class AccountServiceImpl implements IAccountService{

    @Autowired
    private IAccountDao accountDao;


    @Override
    public List findAllAccount() {
       return accountDao.findAllAccount();
    }

        ...

        

@Override
public void transfer(String sourceName, String targetName, Float money) {
    System.out.println("transfer....");
        //2.1根据名称查询转出账户
        Account source = accountDao.findAccountByName(sourceName);
        //2.2根据名称查询转入账户
        Account target = accountDao.findAccountByName(targetName);
        //2.3转出账户减钱
        source.setMoney(source.getMoney()-money);
        //2.4转入账户加钱
        target.setMoney(target.getMoney()+money);
        //2.5更新转出账户
        accountDao.updateAccount(source);

        int i=1/0;

        //2.6更新转入账户
        accountDao.updateAccount(target);
}

...

 

TransactionManager:

注意：因为分别配置前置通知后置通知会存在顺序问题

1.前置通知2.最终通知释放资源导致连接被回收3.执行方法4.后置通知/异常通知

所以一般会配置环绕通知来解决。

/**
 * 和事务管理相关的工具类，它包含了，开启事务，提交事务，回滚事务和释放连接
 */
@Component("txManager")
@Aspect
public class TransactionManager {

    @Autowired
    private ConnectionUtils connectionUtils;

    @Pointcut("execution(* com.itheima.service.impl.*.*(..))")
    private void pt1(){}


    /**
     * 开启事务
     */
    public  void beginTransaction(){
        try {
            connectionUtils.getThreadConnection().setAutoCommit(false);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 提交事务
     */
    public  void commit(){
        try {
            connectionUtils.getThreadConnection().commit();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 回滚事务
     */
    public  void rollback(){
        try {
            connectionUtils.getThreadConnection().rollback();
        }catch (Exception e){
            e.printStackTrace();
        }
    }


    /**
     * 释放连接
     */
    public  void release(){
        try {
            connectionUtils.getThreadConnection().close();//还回连接池中
            connectionUtils.removeConnection();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    @Around("pt1()")
    public Object aroundAdvice(ProceedingJoinPoint pjp){
        Object rtValue = null;
        try {
            //1.获取参数
            Object[] args = pjp.getArgs();
            //2.开启事务
            this.beginTransaction();
            //3.执行方法
            rtValue = pjp.proceed(args);
            //4.提交事务
            this.commit();

            //返回结果
            return  rtValue;

        }catch (Throwable e){
            //5.回滚事务
            this.rollback();
            throw new RuntimeException(e);
        }finally {
            //6.释放资源
            this.release();
        }
    }
}

测试类：

/**
 * 使用Junit单元测试：测试我们的配置
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:bean.xml")
public class AccountServiceTest {

    @Autowired
    private  IAccountService as;

    @Test
    public  void testTransfer(){
        as.transfer("aaa","bbb",100f);
    }

}