SpringBoot中配置多数据源的方法详解

@SpringBootApplication(scanBasePackages = "com", exclude = {DataSourceAutoConfiguration.class})

@Configuration
@Slf4j
public class DataSourceConfigurer {

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

    @Value("${spring.datasource.druid.master.username}")
    private String username;

    @Value("${spring.datasource.druid.master.password}")
    private String password;

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

    /**
     * 获取数据源配置信息
     *
     * @return 数据源配置信息
     */
    private Map<String, Object> getProperties() {
        Map<String, Object> map = new HashMap<>();
        map.put("driverClassName", driverClassName);
        map.put("url", url);
        map.put("username", username);
        map.put("password", password);
        return map;
    }

    /**
     * 配置动态数据源
     *
     * @return 动态数据源
     */
    @Bean("dynamicDataSource")
    public DynamicRoutingDataSource dynamicDataSource() {
        DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
        
        // 创建数据源
        DataSource dataSource = dynamicRoutingDataSource.dataSource(getProperties());
        
        // 设置数据源映射
        Map<Object, Object> dataSourceMap = new HashMap<>(1);
        dataSourceMap.put("default_db", dataSource);
        dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);
        
        // 设置默认数据源
        dynamicRoutingDataSource.setDefaultTargetDataSource(dataSource);
        
        return dynamicRoutingDataSource;
    }
}

/**
 * 动态数据源
 */
@Slf4j
public class DynamicRoutingDataSource extends AbstractRoutingDataSource {

    private static Map<Object, Object> targetTargetDataSources = new ConcurrentHashMap<>();

    @Override
    protected Object determineCurrentLookupKey() {
        // 每次连接数据库，都会去设置数据源
        return DynamicDataSourceContextHolder.getDataSourceKey();
    }

    // 设置targetDataSources并记录数据源（这里可以记录每个数据源的最近使用时间，可以做删除不经常使用的数据源）
    @Override
    public void setTargetDataSources(Map<Object, Object> targetDataSources) {
        super.setTargetDataSources(targetDataSources);
        super.afterPropertiesSet();
        targetTargetDataSources = targetDataSources;
    }

    // 添加数据源
    public void addDataSource(String tenant, Map<String, Object> dataSourceProperties) {
        targetTargetDataSources.put(tenant, dataSource(dataSourceProperties));
        super.setTargetDataSources(targetTargetDataSources);
        afterPropertiesSet();
    }

    // 判断是否存在数据源，存在直接取
    public boolean existDataSource(String tenant) {
        return targetTargetDataSources.containsKey(tenant);
    }

    // 组装数据源
    public DataSource dataSource(Map<String, Object> dataSourceProperties) {
        DataSource dataSource;
        try {
            dataSource = DruidDataSourceFactory.createDataSource(dataSourceProperties);
        } catch (Exception e) {
            log.error("dataSource: {}", e.getMessage());
            throw new RuntimeException();
        }
        return dataSource;
    }
}