@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;

    /**
     * 獲取數(shù)據(jù)源配置信息
     *
     * @return 數(shù)據(jù)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;
    }

    /**
     * 配置動態(tài)數(shù)據(jù)源
     *
     * @return 動態(tài)數(shù)據(jù)源
     */
    @Bean("dynamicDataSource")
    public DynamicRoutingDataSource dynamicDataSource() {
        DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
        
        // 創(chuàng)建數(shù)據(jù)源
        DataSource dataSource = dynamicRoutingDataSource.dataSource(getProperties());
        
        // 設(shè)置數(shù)據(jù)源映射
        Map<Object, Object> dataSourceMap = new HashMap<>(1);
        dataSourceMap.put("default_db", dataSource);
        dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);
        
        // 設(shè)置默認(rèn)數(shù)據(jù)源
        dynamicRoutingDataSource.setDefaultTargetDataSource(dataSource);
        
        return dynamicRoutingDataSource;
    }
}

/**
 * 動態(tài)數(shù)據(jù)源
 */
@Slf4j
public class DynamicRoutingDataSource extends AbstractRoutingDataSource {

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

    @Override
    protected Object determineCurrentLookupKey() {
        // 每次連接數(shù)據(jù)庫，都會去設(shè)置數(shù)據(jù)源
        return DynamicDataSourceContextHolder.getDataSourceKey();
    }

    // 設(shè)置targetDataSources并記錄數(shù)據(jù)源（這里可以記錄每個數(shù)據(jù)源的最近使用時間，可以做刪除不經(jīng)常使用的數(shù)據(jù)源）
    @Override
    public void setTargetDataSources(Map<Object, Object> targetDataSources) {
        super.setTargetDataSources(targetDataSources);
        super.afterPropertiesSet();
        targetTargetDataSources = targetDataSources;
    }

    // 添加數(shù)據(jù)源
    public void addDataSource(String tenant, Map<String, Object> dataSourceProperties) {
        targetTargetDataSources.put(tenant, dataSource(dataSourceProperties));
        super.setTargetDataSources(targetTargetDataSources);
        afterPropertiesSet();
    }

    // 判斷是否存在數(shù)據(jù)源，存在直接取
    public boolean existDataSource(String tenant) {
        return targetTargetDataSources.containsKey(tenant);
    }

    // 組裝數(shù)據(jù)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;
    }
}