在SpringBoot项目中动态切换数据源和数据库的详细步骤

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>com.zaxxer</groupId>
    <artifactId>HikariCP</artifactId> <!-- 使用 HikariCP 作为连接池 -->
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

# 主数据源配置
spring.datasource.primary.url=jdbc:mysql://localhost:3306/primary_db
spring.datasource.primary.username=root
spring.datasource.primary.password=root_password
spring.datasource.primary.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.primary.hikari.maximum-pool-size=10

# 从数据源配置
spring.datasource.secondary.url=jdbc:mysql://localhost:3306/secondary_db
spring.datasource.secondary.username=root
spring.datasource.secondary.password=root_password
spring.datasource.secondary.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.secondary.hikari.maximum-pool-size=10

public class DynamicDataSource extends AbstractRoutingDataSource {

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

public class DataSourceContextHolder {

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

    public static void setDataSourceType(String dataSourceType) {
        contextHolder.set(dataSourceType);
    }

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

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

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.example.repository")
public class DataSourceConfig {

    @Primary
    @Bean
    public DynamicDataSource dynamicDataSource(
        @Qualifier("primaryDataSource") DataSource primaryDataSource,
        @Qualifier("secondaryDataSource") DataSource secondaryDataSource) {
        
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put("primary", primaryDataSource);
        targetDataSources.put("secondary", secondaryDataSource);

        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        dynamicDataSource.setDefaultTargetDataSource(primaryDataSource);
        dynamicDataSource.setTargetDataSources(targetDataSources);
        return dynamicDataSource;
    }

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

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

@Service
public class DataService {

    // 使用主数据源
    public void usePrimaryDataSource() {
        DataSourceContextHolder.setDataSourceType("primary");
        // 执行主数据库相关操作
    }

    // 使用从数据源
    public void useSecondaryDataSource() {
        DataSourceContextHolder.setDataSourceType("secondary");
        // 执行从数据库相关操作
    }

    // 清除数据源设置
    public void clearDataSource() {
        DataSourceContextHolder.clearDataSourceType();
    }
}

@RestController
@RequestMapping("/data")
public class DataController {

    @Autowired
    private DataService dataService;

    @GetMapping("/usePrimary")
    public String usePrimaryDataSource() {
        dataService.usePrimaryDataSource();
        return "Using Primary DataSource";
    }

    @GetMapping("/useSecondary")
    public String useSecondaryDataSource() {
        dataService.useSecondaryDataSource();
        return "Using Secondary DataSource";
    }
}

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface DataSourceSwitch {
    String value() default "primary"; // 默认使用主数据源
}

@Aspect
@Component
public class DataSourceAspect {

    @Before("@annotation(dataSourceSwitch)")
    public void switchDataSource(DataSourceSwitch dataSourceSwitch) {
        String dataSourceType = dataSourceSwitch.value();
        DataSourceContextHolder.setDataSourceType(dataSourceType);
    }

    @After("@annotation(dataSourceSwitch)")
    public void clearDataSource(DataSourceSwitch dataSourceSwitch) {
        DataSourceContextHolder.clearDataSourceType();
    }
}

@Service
public class DataService {

    @DataSourceSwitch("primary")
    public void usePrimaryDataSource() {
        // 使用主数据源
    }

    @DataSourceSwitch("secondary")
    public void useSecondaryDataSource() {
        // 使用从数据源
    }
}