SpringBoot动态切换多数据源

@Bean(name = "dataSource")
public DataSource dataSource() {
    DruidDataSource druidDataSource = new DruidDataSource();
    druidDataSource.setUrl(url);
    druidDataSource.setUsername(username);
    druidDataSource.setDriverClassName(driverClassName);
    druidDataSource.setPassword(password);
    return druidDataSource;
}

@Bean(initMethod = "init")
  @ConditionalOnMissingBean
  public DataSource dataSource() {
      LOGGER.info("Init DruidDataSource");
      return new DruidDataSourceWrapper();
  }

/**
     * @Bean：向IOC容器中注入一个Bean
     * @ConfigurationProperties：使得配置文件中以spring.datasource为前缀的属性映射到Bean的属性中
     * @return
     */
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource dataSource(){
        //做一些其他的自定义配置，比如密码加密等......
        return new DruidDataSource();
    }

@EnableConfigurationProperties(MybatisProperties.class)

@Bean
@ConditionalOnMissingBean
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {}

/**
    * 注入SqlSessionFactory
    */
   @Bean("sqlSessionFactory1")
   public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
       SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
       sqlSessionFactoryBean.setDataSource(dataSource);
       sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/**/*.xml"));
       org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
       // 自动将数据库中的下划线转换为驼峰格式
       configuration.setMapUnderscoreToCamelCase(true);
       configuration.setDefaultFetchSize(100);
       configuration.setDefaultStatementTimeout(30);
       sqlSessionFactoryBean.setConfiguration(configuration);
       return sqlSessionFactoryBean.getObject();
   }

@ConditionalOnSingleCandidate(DataSource.class)

private Map<Object, Object> targetDataSources;

protected abstract Object determineCurrentLookupKey();

/**
 * 使用ThreadLocal存储切换数据源后的KEY
 */
public class DataSourceHolder {

    //线程  本地环境
    private static final ThreadLocal<String> dataSources = new InheritableThreadLocal();

    //设置数据源
    public static void setDataSource(String datasource) {
        dataSources.set(datasource);
    }

    //获取数据源
    public static String getDataSource() {
        return dataSources.get();
    }

    //清除数据源
    public static void clearDataSource() {
        dataSources.remove();
    }
}

/**
 * 动态数据源，继承AbstractRoutingDataSource
 */
public class DynamicDataSource extends AbstractRoutingDataSource {

    /**
     * 返回需要使用的数据源的key，将会按照这个KEY从Map获取对应的数据源（切换）
     * @return
     */
    @Override
    protected Object determineCurrentLookupKey() {
        //从ThreadLocal中取出KEY
        return DataSourceHolder.getDataSource();
    }

    /**
     * 构造方法填充Map，构建多数据源
     */
    public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
        //默认的数据源，可以作为主数据源
        super.setDefaultTargetDataSource(defaultTargetDataSource);
        //目标数据源
        super.setTargetDataSources(targetDataSources);
        //执行afterPropertiesSet方法，完成属性的设置
        super.afterPropertiesSet();
    }
}

/**
 * 切换数据源的注解
 */
@Target(value = ElementType.METHOD)
@Retention(value = RetentionPolicy.RUNTIME)
@Documented
public @interface SwitchSource {

    /**
     * 默认切换的数据源KEY
     */
    String DEFAULT_NAME = "hisDataSource";

    /**
     * 需要切换到数据的KEY
     */
    String value() default DEFAULT_NAME;
}

@Aspect
//优先级要设置在事务切面执行之前
@Order(1)
@Component
@Slf4j
public class DataSourceAspect {


    @Pointcut("@annotation(SwitchSource)")
    public void pointcut() {
    }

    /**
     * 在方法执行之前切换到指定的数据源
     * @param joinPoint
     */
    @Before(value = "pointcut()")
    public void beforeOpt(JoinPoint joinPoint) {
        /*因为是对注解进行切面，所以这边无需做过多判定，直接获取注解的值，进行环绕，将数据源设置成远方，然后结束后，清楚当前线程数据源*/
        Method method = ((MethodSignature) joinPoint.getSignature()).getMethod();
        SwitchSource switchSource = method.getAnnotation(SwitchSource.class);
        log.info("[Switch DataSource]:" + switchSource.value());
        DataSourceHolder.setDataSource(switchSource.value());
    }

    /**
     * 方法执行之后清除掉ThreadLocal中存储的KEY，这样动态数据源会使用默认的数据源
     */
    @After(value = "pointcut()")
    public void afterOpt() {
        DataSourceHolder.clearDataSource();
        log.info("[Switch Default DataSource]");
    }
}

/**
     * 创建动态数据源的SqlSessionFactory，传入的是动态数据源
     * @Primary这个注解很重要，如果项目中存在多个SqlSessionFactory，这个注解一定要加上
     */
    @Primary
    @Bean("sqlSessionFactory2")
    public SqlSessionFactory sqlSessionFactoryBean(DynamicDataSource dynamicDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dynamicDataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/**/*.xml"));
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setDefaultFetchSize(100);
        configuration.setDefaultStatementTimeout(30);
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }

/**
    * @Bean：向IOC容器中注入一个Bean
    * @ConfigurationProperties：使得配置文件中以spring.datasource为前缀的属性映射到Bean的属性中
    */
   @ConfigurationProperties(prefix = "spring.datasource")
   @Bean("dataSource")
   public DataSource dataSource(){
       return new DruidDataSource();
   }

   /**
    * 向IOC容器中注入另外一个数据源
    * 全局配置文件中前缀是spring.datasource.his
    */
   @Bean(name = SwitchSource.DEFAULT_NAME)
   @ConfigurationProperties(prefix = "spring.datasource.his")
   public DataSource hisDataSource() {
       return DataSourceBuilder.create().build();
   }

/**
     * 创建动态数据源的SqlSessionFactory，传入的是动态数据源
     * @Primary这个注解很重要，如果项目中存在多个SqlSessionFactory，这个注解一定要加上
     */
    @Primary
    @Bean("sqlSessionFactory2")
    public SqlSessionFactory sqlSessionFactoryBean(DynamicDataSource dynamicDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dynamicDataSource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setDefaultFetchSize(100);
        configuration.setDefaultStatementTimeout(30);
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }

/**
  * 重写事务管理器，管理动态数据源
  */
 @Primary
 @Bean(value = "transactionManager2")
 public PlatformTransactionManager annotationDrivenTransactionManager(DynamicDataSource dataSource) {
     return new DataSourceTransactionManager(dataSource);
 }

//不开启事务
@Transactional(propagation = Propagation.NOT_SUPPORTED)
//切换到HIS的数据源
@SwitchSource
@Override
public List<DeptInfo> list() {
    return hisDeptInfoMapper.listDept();
}