1、DataSourceContextHolder

public class DataSourceContextHolder {
    private static final Logger log = LoggerFactory.getLogger(DataSourceContextHolder.class);

    /**
     * 默认数据源
     */
    static final String DEFAULT_DS = "db-read";

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();

    // 设置数据源名
    public static void setDB(String dbType) {
        log.info("切换到{}数据源", dbType);
        contextHolder.set(dbType);
    }

    // 获取数据源名
    static String getDB() {
        return contextHolder.get();
    }

    // 清除数据源名
    static void clearDB() {
        contextHolder.remove();
    }
}

2、DataSourceExampleConfig

@Configuration
@MapperScan(basePackages = {
    "com.example.common.dao.example" }, sqlSessionFactoryRef = "exampleSqlSessionFactory", sqlSessionTemplateRef = "exampleSqlSessionTemplate")
public class DataSourceExampleConfig {

    @Primary
    @Bean(name = "exampleDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.example")
    public DataSource exampleDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "exampleReadDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.example.read")
    public DataSource exampleReadDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "dynamicSource")
    public DynamicDataSource dynamicSource(@Qualifier("exampleDataSource") DataSource exampleDataSource,
            @Qualifier("exampleReadDataSource") DataSource exampleReadDataSource) {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        // 默认数据源
        dynamicDataSource.setDefaultTargetDataSource(exampleReadDataSource);
        // 配置多数据源
        Map<Object, Object> dsMap = new HashMap<>();
        dsMap.put("db-master", exampleDataSource);
        dsMap.put("db-read", exampleReadDataSource);
        dynamicDataSource.setTargetDataSources(dsMap);
        return dynamicDataSource;
    }

    @Bean(name = "exampleSqlSessionFactory")
    public SqlSessionFactory exampleSqlSessionFactory(@Qualifier("dynamicSource") DataSource dynamicSource)
            throws Exception { // NOSONAR
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dynamicSource);
        sqlSessionFactoryBean.setMapperLocations(
                new PathMatchingResourcePatternResolver().getResources("classpath:mappers/example/*.xml"));
        return sqlSessionFactoryBean.getObject();
    }

    @Bean
    public DataSourceTransactionManager exampleTransactionManager(
            @Qualifier("dynamicSource") DataSource dynamicSource) { // NOSONAR
        return new DataSourceTransactionManager(dynamicSource);
    }

    @Bean(name = "exampleSqlSessionTemplate")
    public SqlSessionTemplate exampleSqlSessionTemplate(
            @Qualifier("exampleSqlSessionFactory") SqlSessionFactory sqlSessionFactory) { // NOSONAR
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

3、DbKey

public class DbKey {

    /**
     * 读数据库
     */
    public static final String DBREAD = "db-read";

    /**
     * 写数据库
     */
    public static final String DBMASTER = "db-master";

    private DbKey() {

    }
}

4、DynamicDataSource

public class DynamicDataSource extends AbstractRoutingDataSource {
    private static final Logger log = LoggerFactory.getLogger(DynamicDataSource.class);

    @Override
    protected Object determineCurrentLookupKey() {
        log.debug("数据源为{}", DataSourceContextHolder.getDB());
        return DataSourceContextHolder.getDB();
    }

}

5、DynamicDataSourceAspect

@Aspect
@Component
public class DynamicDataSourceAspect {
    private static final Logger LOGGER = LoggerFactory.getLogger(DynamicDataSourceAspect.class);

    @SuppressWarnings("rawtypes")
    @Before("execution(* com.example.manage.controller..*.*(..))")
    public void beforeSwitchDS(JoinPoint point) {

        // 获得当前访问的class
        Class<?> clazz = point.getTarget().getClass();
        // 获得访问的方法名
        String methodName = point.getSignature().getName();
        // 得到方法的参数的类型
        Class[] argClass = ((MethodSignature) point.getSignature()).getParameterTypes();
        String dataSource = DataSourceContextHolder.DEFAULT_DS;
        try {
            // 得到访问的方法对象
            Method method = clazz.getMethod(methodName, argClass);
            // 判断是否存在@DS注解
            if (method.isAnnotationPresent(DBSource.class)) {
                DBSource annotation = method.getAnnotation(DBSource.class);
                // 取出注解中的数据源名
                dataSource = annotation.value();
            }
        } catch (Exception e) {
            LOGGER.error("beforeSwitchDS error", e);
        }
        // 切换数据源
        DataSourceContextHolder.setDB(dataSource);
    }

    @After("execution(* com.example.manage.controller..*.*(..))")
    public void afterSwitchDS(JoinPoint point) {
        DataSourceContextHolder.clearDB();
    }

}

6 切点 DBSource

@Target({ ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface DBSource {
    String value() default "db-master";
}

7、application.properties 配置（@@是配置文件里获取的）

#写配置
spring.datasource.example.url=@spring.datasource.example.url@
spring.datasource.example.username=@spring.datasource.example.username@
spring.datasource.example.password=@spring.datasource.example.password@
spring.datasource.example.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.example.remove-abandoned-timeout=180
spring.datasource.example.testOnReturn=false
spring.datasource.example.initial-size=2
spring.datasource.example.min-evictable-idle-time-millis=300000
spring.datasource.example.max-active=20
spring.datasource.example.testWhileIdle=true
spring.datasource.example.min-idle=1
spring.datasource.example.poolPreparedStatements=true
spring.datasource.example.testOnBorrow=false
spring.datasource.example.max-wait=60000
spring.datasource.example.time-between-eviction-runs-millis=3000
spring.datasource.example.max-idle=10
spring.datasource.example.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.example.remove-abandoned=true
spring.datasource.example.connection-properties=clientEncoding=UTF-8
spring.datasource.example.default-auto-commit=true
spring.datasource.example.validation-query=select 1

#读配置
spring.datasource.example.read.url=@spring.datasource.example.read.url@
spring.datasource.example.read.username=@spring.datasource.example.read.username@
spring.datasource.example.read.password=@spring.datasource.example.read.password@
spring.datasource.example.read.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.example.read.remove-abandoned-timeout=180
spring.datasource.example.read.testOnReturn=false
spring.datasource.example.read.initial-size=2
spring.datasource.example.read.min-evictable-idle-time-millis=300000
spring.datasource.example.read.max-active=20
spring.datasource.example.read.testWhileIdle=true
spring.datasource.example.read.min-idle=1
spring.datasource.example.read.poolPreparedStatements=true
spring.datasource.example.read.testOnBorrow=false
spring.datasource.example.read.max-wait=60000
spring.datasource.example.read.time-between-eviction-runs-millis=3000
spring.datasource.example.read.max-idle=10
spring.datasource.example.read.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.example.read.remove-abandoned=true
spring.datasource.example.read.connection-properties=clientEncoding=UTF-8
spring.datasource.example.read.default-auto-commit=true
spring.datasource.example.read.validation-query=select 1

切换举例子，PS 目前由于事务的原因，注解是放在了controller上，这就局限了此方法及调用的service用同一个数据源。如果有更好的解决方案，请赐教

    @PostMapping("***")
    @ApiOperation(value = "启用/禁用***的状态", response = Response.class, notes = "启用/禁用***的状态")
    @DBSource(DbKey.DBMASTER)
    public Response<Object> reviseListState(@RequestBody ReviseListStateParam reviseListStateParam) {
        listService.reviseListState(reviseListStateParam);
        return Response.R200;
    }