Seata使用

Seata使用

使用seata进行分布式事务非常的简单，只是依赖于一个seata server服务，首先将服务启动，然后对微服务进行配置

依赖

<!-- seata 依赖-->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
    <exclusions>
        <exclusion>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<!-- 排除掉原本的依赖，选择和使用的seata server版本相同的 -->
<dependency>
    <groupId>io.seata</groupId>
    <artifactId>seata-all</artifactId>
    <version>1.1.0</version>
</dependency>

配置

mybatis:
  config-location: classpath:mybatis/mybatis.cfg.xml  # mybatis配置文件
  type-aliases-package: com.zhanghe.study.springcloudalibaba.model  #Entity所在包
  mapper-locations:
    - classpath:mybatis/mapper/**/*.xml   #mapper文件

spring:
  application:
    name: springcloudalibaba-seata-order
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080 #sentinel dashboard 地址
        port: 8719 #默认是8719，如果被占用，则会自动从8719开始依次+1扫描，直至找到未被占用的端口
    alibaba:
      seata:
        tx-service-group: my_test_tx_group # 事务组名称，要与seata server中file.conf中配置的service中vgroupMapping一致
    nacos:
      discovery:
        server-addr: localhost:8848
  datasource:
    druid:
      username: root
      password: 123456
      url: jdbc:mysql://localhost:3306/seata_order
      driver-class-name: com.mysql.jdbc.Driver
feign:
  sentinel:
    enabled: true

将seata server中配置好的file.conf和registry.conf也要拷贝到项目的资源路径下

启动类

启动类要排除掉DataSourceAutoConfiguration，因为需要修改数据源，不使用默认的配置

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class) 
@EnableDiscoveryClient
@EnableFeignClients
public class OrderApp {
    public static void main(String[] args) {
        SpringApplication.run(OrderApp.class,args);
    }
}

数据源配置

这里要使用Seata的数据源进行代理

// 使用seata数据源进行代理
@Configuration
@EnableConfigurationProperties({MybatisProperties.class})
public class DataSourceConfiguration {


    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.druid")
    public DataSource dataSource() {
        return new DruidDataSource();
    }

    @Bean
    public DataSourceProxy dataSourceProxy(DataSource dataSource) {
        return new DataSourceProxy(dataSource);
    }

    @Bean
    public SqlSessionFactoryBean sqlSessionFactoryBean(DataSourceProxy dataSourceProxy,
                                                       MybatisProperties mybatisProperties) {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSourceProxy);

        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        try {
            Resource[] mapperLocaltions = resolver.getResources(mybatisProperties.getMapperLocations()[0]);
            bean.setMapperLocations(mapperLocaltions);

            if (StringUtils.isNotBlank(mybatisProperties.getConfigLocation())) {
                Resource[] resources = resolver.getResources(mybatisProperties.getConfigLocation());
                bean.setConfigLocation(resources[0]);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return bean;
    }
}

在业务方法上使用@GlobalTransactional注解进行标注全局事务

@GlobalTransactional(name = "create-order",rollbackFor = Exception.class)
public void create(Order order){
    System.out.println("创建订单");
    orderDao.addOrder(order);

    System.out.println("扣减库存");
    storageClient.decrease(order.getProductId(),order.getCount());

    System.out.println("账户余额扣减");
    accountClient.decrease(order.getUserId(),order.getMoney());

    System.out.println("订单状态修改");
    orderDao.updateStatus(order.getId(),order.getStatus());
}