一、事务隔离的级别（isolation = Isolation.READ_COMMITTED）

最常用的值isolation = Isolation.READ_COMMITTED，读已提交

二、事务异常回滚

三、数据库只读属性，readOnly = false;(true)，此方法只会读取数据库数据而不能更改数据

四、timeout=10,单位是秒，只连接等待时间

package top.biglin.spring.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

/**
 * @author Chiawei
 * @date 2019/1/15 11:28
 */
@Service("bookShopService")
public class BookShopServiceImpl implements BookShopService {

    @Autowired
    private BookShopDao bookShopDao;

    /**
     *添加事务,Propagation.REQUIRED,使用调用原来的事务
     * Propagation.REQUIRES_NEW 新开一个事务
     */
    @Transactional(propagation = Propagation.REQUIRES_NEW,
                    isolation = Isolation.READ_COMMITTED,
                    noRollbackFor = {UserAccountException.class},//对哪些异常不回滚
                    rollbackFor = {top.biglin.spring.tx.UserAccountException.class},
                    timeout = 5,
                    readOnly = false)//对哪些异常进行回滚
    @Override
    public void purchase(String username, String isbn) {

        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
        }
        //获取书的单价
        int price = bookShopDao.findBookPriceByIsbn(isbn);

        //更新书的库存
        bookShopDao.updateBookStock(isbn);

        //更新余额
        bookShopDao.updateUserAccount(username, price);
    }
}