变态需求之【角色不同访问数据库的用户不同】

需求说明

不同的用户角色在访问系统的时候，后台要根据角色切换不同的数据库用户名和密码。

你就说变不变态吧。。。。

环境说明

复制代码

数据库：mysql8.0
jdk17
SpringBoot 2.7.6
mybatis plus 3.5.5

以下为代码讲解，可跳过自行拉取代码测试

代码

1、数据源上下文 Holder，存储当前线程的数据源标识

java 复制代码

public class DataSourceContextHolder {

    private static final ThreadLocal<UserType> CONTEXT_HOLDER = new ThreadLocal<>();

    // 设置数据源标识
    public static void setDataSourceType(UserType type) {
        CONTEXT_HOLDER.set(type);
    }

    // 获取数据源标识
    public static UserType getDataSourceType() {
        return CONTEXT_HOLDER.get() == null ? UserType.USER : CONTEXT_HOLDER.get();
    }

    // 清除数据源标识（避免内存泄漏）
    public static void clearDataSourceType() {
        CONTEXT_HOLDER.remove();
    }
}

2、动态数据源，根据ThreadLocal中的标识切换数据源

java 复制代码

/**
 * 动态数据源，根据ThreadLocal中的标识切换数据源
 *
 * @author smallNorth_Lee
 * @since 2026/1/22
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        UserType dataSourceType = DataSourceContextHolder.getDataSourceType();
        return dataSourceType == null ? UserType.ADMIN : dataSourceType;
    }
}

3、数据源拦截器

这里说明一下，模拟的是从请求头获取用户的角色，实际场景中会出现，"用户没有登录我怎么知道他的角色？？"，这里登录的接口肯定要为公共接口，不然没得聊。

java 复制代码

/**
 * 数据源拦截器
 *
 * @author smallNorth_Lee
 * @since 2026/1/22
 */
@Component
public class DataSourceInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
       // TODO 这里模拟用户角色，实际项目中可自行调整，登录的接口肯定为公共的数据源，其它查询的时候需要判断用户角色
        String role = request.getHeader("role");
        if (role == null){
            role = "ADMIN";
        }
        String resLogger = "\n\n==============  request Start  ==============";
        resLogger += "\n当前用户角色为 : " + role;
        if (UserType.ADMIN.name().equals(role.toUpperCase())) {
            resLogger += "\n使用的数据源为 : {ADMIN}";
            DataSourceContextHolder.setDataSourceType(UserType.ADMIN);
        } else if (UserType.USER.name().equals(role.toUpperCase())) {
            resLogger += "\n使用的数据源为 : {USER}";
            DataSourceContextHolder.setDataSourceType(UserType.USER);
        }
        resLogger += "\n==============  request End  ==============\n";
        System.out.println(resLogger);
        return true;
    }

    // 清理数据源
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        DataSourceContextHolder.clearDataSourceType();
    }
}

4、数据源配置

yaml 复制代码

server:
  port: 2026
spring:
  application:
    name: dynamic-datasource
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/auth-center?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true
    user:
      username: root
      password: 123456
    admin:
      username: root
      password: 123456

java 复制代码

/**
 * 数据源配置
 *
 * @author smallNorth_Lee
 * @since 2026/1/22
 */
@Configuration
public class DataSourceConfig {

    @Value("${spring.datasource.url}")
    private String url;

    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;

    @Value("${spring.datasource.admin.username}")
    private String adminUsername;
    @Value("${spring.datasource.admin.password}")
    private String adminPassword;

    @Bean("adminDataSource")
    public DataSource adminDataSource() {
        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl(url);
        dataSource.setUsername(adminUsername);
        dataSource.setPassword(adminPassword);
        dataSource.setDriverClassName(driverClassName);
        dataSource.setMaximumPoolSize(10);
        dataSource.setMinimumIdle(2);
        return dataSource;
    }

    @Value("${spring.datasource.user.username}")
    private String userUsername;
    @Value("${spring.datasource.user.password}")
    private String userPassword;

    @Bean("userDataSource")
    public DataSource userDataSource() {
        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl(url);
        dataSource.setUsername(userUsername);
        dataSource.setPassword(userPassword);
        dataSource.setDriverClassName(driverClassName);
        dataSource.setMaximumPoolSize(10);
        dataSource.setMinimumIdle(2);
        return dataSource;
    }

    @Bean("dynamicDataSource")
    @Primary // 设置为默认数据源
    public DataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        // 初始化数据源映射
        Map<Object, Object> dataSourceMap = new HashMap<>();
        dataSourceMap.put(UserType.ADMIN, adminDataSource());
        dataSourceMap.put(UserType.USER, userDataSource());
        // 设置数据源映射
        dynamicDataSource.setTargetDataSources(dataSourceMap);
        // 设置默认数据源
        dynamicDataSource.setDefaultTargetDataSource(adminDataSource());
        return dynamicDataSource;
    }

    // 事务管理
    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(dynamicDataSource());
    }
}

5、MyBatisPlus 配置类

java 复制代码

/**
 * MyBatisPlus 配置类
 *
 * @author smallNorth_Lee
 * @since 2026/1/22
 */
@Configuration
public class MyBatisPlusConfig {

    @Resource
    private DataSource dynamicDataSource;

    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }

    @Bean
    public MybatisSqlSessionFactoryBean sqlSessionFactory() {
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dynamicDataSource);
        return sqlSessionFactory;
    }
}

6、web配置，注册拦截器

java 复制代码

/**
 * web配置，注册拦截器
 *
 * @author smallNorth_Lee
 * @since 2026/1/22
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new DataSourceInterceptor()).addPathPatterns("/**");
    }
}

其它都是CRUD基础操作，可拉取代码测试哦，代码地址：一给我里giaogiao