（二十）、SpringCloud Alibaba Seata处理分布式事务

service {
    ##fsp_tx_group是自定义的
    vgroup_mapping.my.test.tx_group="fsp_tx_group" 
    default.grouplist = "127.0.0.1:8091"
    enableDegrade = false
    disable = false
    max.commitretry.timeout= "-1"
    max.ollbackretry.timeout= "-1"
}

## transaction log store
store {
  ## store mode: file, db
  ## 改成db
  mode = "db"
  ## file store
  file {
    dir = "sessionStore"
    # branch session size, if exceeded first try compress lockkey, still exceeded throws exceptions
    max-branch-session-size = 16384
    # globe session size, if exceeded throws exceptions
    max-global-session-size = 512
    # file buffer size, if exceeded allocate new buffer
    file-write-buffer-cache-size = 16384
    # when recover batch read size
    session.reload.read_size= 100
    # async, sync
    flush-disk-mode = async
  }
  # database store
  db {
    ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc.
    datasource = "dbcp"
    ## mysql/oracle/h2/oceanbase etc.
    ## 配置数据源
    db-type = "mysql"
    driver-class-name = "com.mysql.jdbc.Driver"
    url = "jdbc:mysql://127.0.0.1:3306/seata"
    user = "root"
    password = "你自己密码"
    min-conn= 1
    max-conn = 3
    global.table = "global_table"
    branch.table = "branch_table"
    lock-table = "lock_table"
    query-limit = 100
  }
}

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  # 改用为nacos
  type = "nacos"
  nacos {
    ## 加端口号
    serverAddr = "localhost:8848"
    namespace = ""
    cluster = "default"
  }
  ...
}

CREATE TABLE t_order (
    `id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY key,
    `user_id` BIGINT(11) DEFAULT NULL COMMENT '用户id',
    `product_id` BIGINT(11) DEFAULT NULL COMMENT '产品id',
    `count` INT(11) DEFAULT NULL COMMENT '数量',
    `money` DECIMAL(11,0) DEFAULT NULL COMMENT'金额',
    `status` INT(1) DEFAULT NULL COMMENT '订单状态'
) ENGINE=INNODB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;
SELECT * FROM t_order;
CREATE TABLE t_storage (
`id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
`product_id` BIGINT(11) DEFAULT NULL COMMENT '产品id',
`total` INT(11) DEFAULT NULL COMMENT '总库存',
`used` INT(11) DEFAULT NULL COMMENT '已用库存',
`residue` INT(11) DEFAULT NULL COMMENT '剩余库存'
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO t_storage(`id`, `product_id`, `total`, `used`, `residue`)
VALUES ('1', '1', '100', '0','100');
SELECT * FROM t_storage;
create  TABLE t_account(
  `id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'id',
  `user_id` BIGINT(11) DEFAULT NULL COMMENT '用户id',
  `total` DECIMAL(10,0) DEFAULT NULL COMMENT '总额度',
  `used` DECIMAL(10,0) DEFAULT NULL COMMENT '已用余额',
  `residue` DECIMAL(10,0) DEFAULT '0' COMMENT '剩余可用额度'
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO t_account(`id`, `user_id`, `total`, `used`, `residue`)
VALUES ('1', '1', '1000', '0', '1000');

drop table `undo_log`;
CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `branch_id` bigint(20) NOT NULL,
  `xid` varchar(100) NOT NULL,
  `context` varchar(128) NOT NULL,
  `rollback_info` longblob NOT NULL,
  `log_status` int(11) NOT NULL,
  `log_created` datetime NOT NULL,
  `log_modified` datetime NOT NULL,
  `ext` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1

@Service
public class AccountServiceImpl implements AccountService {
    private static final Logger LOGGER = LoggerFactory.getLogger(AccountServiceImpl.class);
    @Resource
    AccountDao accountDao;
    /**
     * 扣减账户余额
     */
    @Override
    public void decrease(Long userId, BigDecimal money) {
        LOGGER.info("------->account-service中扣减账户余额开始");
        //模拟超时异常，全局事务回滚
        //暂停几秒钟线程
        try { TimeUnit.SECONDS.sleep(20); } catch (InterruptedException e) { e.printStackTrace(); }
        accountDao.decrease(userId,money);
        LOGGER.info("------->account-service中扣减账户余额结束");
    }
}

@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
    ...
    /**
     * 创建订单->调用库存服务扣减库存->调用账户服务扣减账户余额->修改订单状态
     * 简单说：下订单->扣库存->减余额->改状态
     */
    @Override
    //rollbackFor = Exception.class表示对任意异常都进行回滚
    @GlobalTransactional(name = "fsp-create-order",rollbackFor = Exception.class)
    public void create(Order order)
    {
    ...
    }
}