如果用AbstractRoutingDataSource实现Hikari呢

使用AbstractRoutingDataSource实现Hikari数据源切换，可以按照以下步骤进行：

1.在pom.xml文件中添加HikariCP和Spring JDBC依赖：

<dependency>
    <groupId>com.zaxxer</groupId>
    <artifactId>HikariCP</artifactId>
    <version>3.4.5</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.3.9</version>
</dependency>

2.创建HikariDataSource实例，并将其添加到AbstractRoutingDataSource中：

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return new HikariDataSource();
    }

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource() {
        return new HikariDataSource();
    }

    @Bean
    public AbstractRoutingDataSource routingDataSource() {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put("master", masterDataSource());
        targetDataSources.put("slave", slaveDataSource());

        AbstractRoutingDataSource routingDataSource = new AbstractRoutingDataSource() {
            @Override
            protected Object determineCurrentLookupKey() {
                return DataSourceContextHolder.getDataSource();
            }
        };
        routingDataSource.setDefaultTargetDataSource(masterDataSource());
        routingDataSource.setTargetDataSources(targetDataSources);
        return routingDataSource;
    }
}

3.创建一个DataSourceContextHolder类，用于存储当前线程使用的数据源：

public class DataSourceContextHolder {

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

    public static void setDataSource(String dataSource) {
        contextHolder.set(dataSource);
    }

    public static String getDataSource() {
        return contextHolder.get();
    }

    public static void clearDataSource() {
        contextHolder.remove();
    }
}

4.创建一个AOP切面，用于在方法调用前设置当前线程使用的数据源：

@Aspect
@Component
public class DataSourceAspect {

    @Pointcut("@annotation(com.example.demo.annotation.DataSource)")
    public void dataSourcePointCut() {
    }

    @Before("dataSourcePointCut()")
    public void before(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        DataSource dataSource = signature.getMethod().getAnnotation(DataSource.class);
        if (dataSource == null) {
            DataSourceContextHolder.setDataSource("master");
        } else {
            DataSourceContextHolder.setDataSource(dataSource.value());
        }
    }

    @After("dataSourcePointCut()")
    public void after(JoinPoint joinPoint) {
        DataSourceContextHolder.clearDataSource();
    }
}

5.在需要使用不同数据源的方法上添加@DataSource注解：

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;

    @Override
    @DataSource("master")
    public User getUserById(int id) {
        return userDao.getUserById(id);
    }

    @Override
    @DataSource("slave")
    public List<User> getAllUsers() {
        return userDao.getAllUsers();
    }
}