使用Spring Boot實現MySQL的讀寫分離可以通過配置多個數據源，并在不同的服務中處理讀寫操作。下面是一個簡單的示例：

1. 配置application.properties文件：

# 主數據源
spring.datasource.master.url=jdbc:mysql://localhost:3306/masterdb
spring.datasource.master.username=root
spring.datasource.master.password=root

# 從數據源
spring.datasource.slave.url=jdbc:mysql://localhost:3306/slavedb
spring.datasource.slave.username=root
spring.datasource.slave.password=root

2. 創建兩個數據源的配置類：

@Configuration
public class DataSourceConfig {
    
    @Primary
    @Bean(name = "masterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

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

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

        RoutingDataSource routingDataSource = new RoutingDataSource();
        routingDataSource.setTargetDataSources(targetDataSources);
        routingDataSource.setDefaultTargetDataSource(masterDataSource);

        return routingDataSource;
    }
}

3. 創建一個自定義的RoutingDataSource類：

public class RoutingDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceContextHolder.getDataSource();
    }
}

4. 創建一個DataSourceContextHolder類用于切換數據源：

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();
    }
}

5. 在需要切換數據源的地方調用DataSourceContextHolder.setDataSource(“master”)或DataSourceContextHolder.setDataSource(“slave”)來切換數據源。

通過以上步驟，可以實現Spring Boot中的MySQL讀寫分離配置。