springboot+mybatis多数据源的事务问题

1.springboot+mybatis实现多数据源后，针对单个数据源我们可以使用@Transactional(name="xxxTransactionManager")

来指定使用的事务管理器，但是如果被注解的方法需要同时支持两个事务管理器呢，这个时候如果用@Transactional注解就不

合适了，属性name只支持字符串类型，所以只能填一个，如果不传name属性，而且项目没有配置默认的事务管理器，在调用方

法时则会抛出未指定默认事务管理器的异常。这个时候，我们可以用编程式事务来解决这个问题。

2.多数据源配置已经完成，但是还没有事务管理器，所以先配置支持事务。

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;
/**
 * 数据源1
 */
@Configuration
@MapperScan(basePackages = "com.example.mybatis.mapper",sqlSessionFactoryRef = "sqlSessionFactoryOne")
public class DataSourceConfigOne {

    @Bean(name = "dataSourceOne")
    @Primary// 表示这个数据源是默认数据源
    // 读取application.properties中的配置参数映射成为一个对象,prefix表示参数的前缀
    @ConfigurationProperties(prefix = "spring.datasource.one")
    public DataSource dataSourceOne() {
        return  DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactoryOne")
    @Primary
    public SqlSessionFactory sqlSessionFactoryOne(@Qualifier("dataSourceOne") DataSource datasource)throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(datasource);
        bean.setMapperLocations(
                // 设置mybatis的xml所在位置
                new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*.xml"));
        bean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);
        return bean.getObject();
    }
    @Bean(name = "transactionManagerOne")
    public PlatformTransactionManager transactionManagerOne(@Qualifier("dataSourceOne") DataSource dataSourceOne) {
        return new DataSourceTransactionManager(dataSourceOne);
    }

    @Primary
    public SqlSessionTemplate sqlsessiontemplateOne(@Qualifier("sqlsessiontemplateOne") SqlSessionFactory sessionfactory) {
        return new SqlSessionTemplate(sessionfactory);
    }
}

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;
/**
 * 数据源2
 */
@Configuration
@MapperScan(basePackages = "com.example.mybatis.mapper2",sqlSessionFactoryRef = "sqlSessionFactoryTwo")
public class DataSourceConfigTwo {
    @Bean(name = "dataSourceTwo")
    // 读取application.properties中的配置参数映射成为一个对象,prefix表示参数的前缀
    @ConfigurationProperties(prefix = "spring.datasource.two")
    public DataSource dataSourceTwo() {
        return  DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactoryTwo")
    public SqlSessionFactory sqlSessionFactoryTwo(@Qualifier("dataSourceTwo") DataSource datasource)throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(datasource);
        bean.setMapperLocations(
                // 设置mybatis的xml所在位置
                new PathMatchingResourcePatternResolver().getResources("classpath:mapper2/*.xml"));
        bean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);//下划线-驼峰映射
        return bean.getObject();
    }
    @Bean(name = "transactionManagerTwo")
    public PlatformTransactionManager transactionManagerTwo(@Qualifier("dataSourceTwo") DataSource dataSourceTwo) {
        return new DataSourceTransactionManager(dataSourceTwo);
    }

    public SqlSessionTemplate sqlsessiontemplateTwo(@Qualifier("sqlsessiontemplateTwo") SqlSessionFactory sessionfactory) {
        return new SqlSessionTemplate(sessionfactory);
    }
}

3.使用自定义注解

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD,ElementType.PARAMETER})
public @interface MoreTransaction {
    String[] value() default {};
}

4.事务切面

@Aspect
@Component
public class TransactionAop {
    @Pointcut("@annotation(com.example.mybatis.config.aop.annotation.MoreTransaction)")
    public void MoreTransaction() {
    }

    @Pointcut("execution(* com.example.mybatis.controller.*.*(..))")
    public void excudeController() {
    }

    @Around(value = "MoreTransaction()&&excudeController()&&@annotation(annotation)")
    public Object twiceAsOld(ProceedingJoinPoint thisJoinPoint, MoreTransaction annotation) throws Throwable {
        Stack<DataSourceTransactionManager> dataSourceTransactionManagerStack = new Stack<>();
        Stack<TransactionStatus> transactionStatuStack = new Stack<>();

        try {
            if (!openTransaction(dataSourceTransactionManagerStack, transactionStatuStack, annotation)) {
                return null;
            }
            Object ret = thisJoinPoint.proceed();
            commit(dataSourceTransactionManagerStack, transactionStatuStack);
            return ret;
        } catch (Throwable e) {
            rollback(dataSourceTransactionManagerStack, transactionStatuStack);
            log.error(String.format("MultiTransactionalAspect, method:%s-%s occors error:",
                    thisJoinPoint.getTarget().getClass().getSimpleName(), thisJoinPoint.getSignature().getName()), e);
            throw e;
        }
    }

    /**
     * 开启事务处理方法
     *
     * @param dataSourceTransactionManagerStack
     * @param transactionStatuStack
     * @param multiTransactional
     * @return
     */
    private boolean openTransaction(Stack<DataSourceTransactionManager> dataSourceTransactionManagerStack,
                                    Stack<TransactionStatus> transactionStatuStack,MoreTransaction multiTransactional) {

        String[] transactionMangerNames = multiTransactional.value();
        if (ArrayUtils.isEmpty(multiTransactional.value())) {
            return false;
        }
        for (String beanName : transactionMangerNames) {
            DataSourceTransactionManager dataSourceTransactionManager =(DataSourceTransactionManager) SpringContextUtil.getBean(beanName);
            TransactionStatus transactionStatus = dataSourceTransactionManager
                    .getTransaction(new DefaultTransactionDefinition());
            transactionStatuStack.push(transactionStatus);
            dataSourceTransactionManagerStack.push(dataSourceTransactionManager);
        }
        return true;
    }

    /**
     * 提交处理方法
     *
     * @param dataSourceTransactionManagerStack
     * @param transactionStatuStack
     */
    private void commit(Stack<DataSourceTransactionManager> dataSourceTransactionManagerStack,
                        Stack<TransactionStatus> transactionStatuStack) {
        while (!dataSourceTransactionManagerStack.isEmpty()) {
            dataSourceTransactionManagerStack.pop().commit(transactionStatuStack.pop());
        }
    }

    /**
     * 回滚处理方法
     * @param dataSourceTransactionManagerStack
     * @param transactionStatuStack
     */
    private void rollback(Stack<DataSourceTransactionManager> dataSourceTransactionManagerStack,
                          Stack<TransactionStatus> transactionStatuStack) {
        while (!dataSourceTransactionManagerStack.isEmpty()) {
            dataSourceTransactionManagerStack.pop().rollback(transactionStatuStack.pop());
        }
    }
}

5.service层两个我要新增的方法，这两个方法是两个数据源（一个是我本地的，一个是阿里云的）

 @Override
    public int addUserInfo(UserInfo record) {
        return userInfoMapper.insert(new UserInfo().setId(UUID.randomUUID().toString()).setUserAccount("吾问无为谓"));
    }

  @Override
    public int addUser(User record) {
        return userMapper.insertSelective(record);
    }

6.controller层的调用方法上使用事务注解，将两个数据源的事务管理器名字作为参数传入。

 @GetMapping("/dataSourceList")
    @ResponseBody
    @MoreTransaction(value = {"transactionManagerOne","transactionManagerTwo"})
    public ResultData getDataSourceList(){
        int i=userService.addUser(new User().setPhone("11111111111").setUserName("哈哈哈"));
        int a=1/0;
        int k=userService.addUserInfo(new UserInfo().setId(UUID.randomUUID().toString()).setUserAccount("吾问无为谓"));
        Map map=new HashMap();
        map.put("k",k);
        return ResultData.success(map);
    }

7.提交请求后会发现控制台报错，但是数据库里面并没有插入数据。

参考链接：https://blog.csdn.net/qq_34322777/article/details/80833935