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,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
    <version>2.2.2.RELEASE</version>
</dependency>

spring:
  cloud:
    alibaba:
      seata:
        tx-service-group: my_test_tx_group
  main:
    allow-circular-references: true
seata:
  enable-auto-data-source-proxy: false
  application-id: dd

@Component
@EnableConfigurationProperties(DruidProperties.class)
public class LoadDataSource {
    @Autowired
    DruidProperties druidProperties;

    public Map<String, DataSourceProxy> loadAllDataSource() {
        Map<String, DataSourceProxy> map = new HashMap<>();
        Map<String, Map<String, String>> ds = druidProperties.getDs();
        try {
            Set<String> keySet = ds.keySet();
            for (String key : keySet) {
                DataSource dataSource = druidProperties.dataSource((DruidDataSource) DruidDataSourceFactory.createDataSource(ds.get(key)));
                DataSourceProxy proxyDs = new DataSourceProxy(dataSource);
                map.put(key, proxyDs);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return map;
    }
}

@Component
public class DynamicDataSource extends AbstractRoutingDataSource {

    public DynamicDataSource(LoadDataSource loadDataSource) {
        //1.設(shè)置所有的數(shù)據(jù)源
        Map<String, DataSourceProxy> allDs = loadDataSource.loadAllDataSource();
        super.setTargetDataSources(new HashMap<>(allDs));
        //2.設(shè)置默認(rèn)的數(shù)據(jù)源
        //將來，并不是所有的方法上都有 @DataSource 注解，對于那些沒有 @DataSource 注解的方法，該使用哪個(gè)數(shù)據(jù)源？
        super.setDefaultTargetDataSource(allDs.get(DataSourceType.DEFAULT_DS_NAME));
        //3
        super.afterPropertiesSet();
    }

    /**
     * 這個(gè)方法用來返回?cái)?shù)據(jù)源名稱，當(dāng)系統(tǒng)需要獲取數(shù)據(jù)源的時(shí)候，會(huì)自動(dòng)調(diào)用該方法獲取數(shù)據(jù)源的名稱
      * @return
     */
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}

@Around("pc()")
public Object around(ProceedingJoinPoint pjp) throws Throwable {
    //獲取方法上面的有效注解
    DataSource dataSource = getDataSource(pjp);
    if (dataSource != null) {
        //獲取注解中數(shù)據(jù)源的名稱
        String value = dataSource.value();
        DynamicDataSourceContextHolder.setDataSourceType(value);
    }
    try {
        return pjp.proceed();
    } finally {
        DynamicDataSourceContextHolder.clearDataSourceType();
    }
}

@Service
public class MasterService {
    @Autowired
    MasterMapper masterMapper;

    @DataSource("master")
    public void addUser(String username, Integer age) {
        masterMapper.addUser(username, age);
    }
}

@Service
public class SlaveService {
    @Autowired
    SlaveMapper slaveMapper;

    @DataSource("slave")
    public void addAccount(String name, Double balance) {
        int i = 1 / 0;
        slaveMapper.addAccount(name, balance);
    }
}

@Service
public class UserService {
    @Autowired
    MasterService masterService;
    @Autowired
    SlaveService slaveService;

    @GlobalTransactional(rollbackFor = Exception.class)
    public void test() {
        masterService.addUser("javaboy.org", 99);
        slaveService.addAccount("javaboy.org", 99.0);
    }
}