TenantConfigEntity（租戶信息）@EqualsAndHashCode(callSuper = false)@Data@FieldDefaults(level = AccessLevel.PRIVATE)public class TenantConfigEntity { /**  * 租戶id  **/ Integer tenantId; /**  * 租戶名稱  **/ String tenantName; /**  * 租戶名稱key  **/ String tenantKey; /**  * 數據庫url  **/ String dbUrl; /**  * 數據庫用戶名  **/ String dbUser; /**  * 數據庫密碼  **/ String dbPassword; /**  * 數據庫public_key  **/ String dbPublicKey;}DataSourceUtil（輔助工具類，非必要）public class DataSourceUtil { private static final String DATA_SOURCE_BEAN_KEY_SUFFIX = "_data_source"; private static final String JDBC_URL_ARGS = "?useUnicode=true&characterEncoding=UTF-8&useOldAliasMetadataBehavior=true&zeroDateTimeBehavior=convertToNull"; private static final String CONNECTION_PROPERTIES = "config.decrypt=true;config.decrypt.key="; /**  * 拼接數據源的spring bean key  */ public static String getDataSourceBeanKey(String tenantKey) {  if (!StringUtils.hasText(tenantKey)) {   return null;  }  return tenantKey + DATA_SOURCE_BEAN_KEY_SUFFIX; } /**  * 拼接完整的JDBC URL  */ public static String getJDBCUrl(String baseUrl) {  if (!StringUtils.hasText(baseUrl)) {   return null;  }  return baseUrl + JDBC_URL_ARGS; } /**  * 拼接完整的Druid連接屬性  */ public static String getConnectionProperties(String publicKey) {  if (!StringUtils.hasText(publicKey)) {   return null;  }  return CONNECTION_PROPERTIES + publicKey; }}

public class DataSourceContextHolder { private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<>(); public static void setDataSourceKey(String tenantKey) {  dataSourceKey.set(tenantKey); } public static String getDataSourceKey() {  return dataSourceKey.get(); } public static void clearDataSourceKey() {  dataSourceKey.remove(); }}

public class DynamicDataSource extends AbstractRoutingDataSource { @Autowired private ApplicationContext applicationContext; @Lazy @Autowired private DynamicDataSourceSummoner summoner; @Lazy @Autowired private TenantConfigDAO tenantConfigDAO; @Override protected String determineCurrentLookupKey() {  String tenantKey = DataSourceContextHolder.getDataSourceKey();  return DataSourceUtil.getDataSourceBeanKey(tenantKey); } @Override protected DataSource determineTargetDataSource() {  String tenantKey = DataSourceContextHolder.getDataSourceKey();  String beanKey = DataSourceUtil.getDataSourceBeanKey(tenantKey);  if (!StringUtils.hasText(tenantKey) || applicationContext.containsBean(beanKey)) {   return super.determineTargetDataSource();  }  if (tenantConfigDAO.exist(tenantKey)) {   summoner.registerDynamicDataSources();  }  return super.determineTargetDataSource(); }}

@Slf4j@Componentpublic class DynamicDataSourceSummoner implements ApplicationListener<ContextRefreshedEvent> { // 跟spring-data-source.xml的默認數據源id保持一致 private static final String DEFAULT_DATA_SOURCE_BEAN_KEY = "defaultDataSource"; @Autowired private ConfigurableApplicationContext applicationContext; @Autowired private DynamicDataSource dynamicDataSource; @Autowired private TenantConfigDAO tenantConfigDAO; private static boolean loaded = false; /**  * Spring加載完成后執行  */ @Override public void onApplicationEvent(ContextRefreshedEvent event) {  // 防止重復執行  if (!loaded) {   loaded = true;   try {    registerDynamicDataSources();   } catch (Exception e) {    log.error("數據源初始化失敗, Exception:", e);   }  } } /**  * 從數據庫讀取租戶的DB配置,并動態注入Spring容器  */ public void registerDynamicDataSources() {  // 獲取所有租戶的DB配置  List<TenantConfigEntity> tenantConfigEntities = tenantConfigDAO.listAll();  if (CollectionUtils.isEmpty(tenantConfigEntities)) {   throw new IllegalStateException("應用程序初始化失敗,請先配置數據源");  }  // 把數據源bean注冊到容器中  addDataSourceBeans(tenantConfigEntities); } /**  * 根據DataSource創建bean并注冊到容器中  */ private void addDataSourceBeans(List<TenantConfigEntity> tenantConfigEntities) {  Map<Object, Object> targetDataSources = Maps.newLinkedHashMap();  DefaultListableBeanFactory beanFactory = (DefaultListableBeanFactory) applicationContext.getAutowireCapableBeanFactory();  for (TenantConfigEntity entity : tenantConfigEntities) {   String beanKey = DataSourceUtil.getDataSourceBeanKey(entity.getTenantKey());   // 如果該數據源已經在spring里面注冊過,則不重新注冊   if (applicationContext.containsBean(beanKey)) {    DruidDataSource existsDataSource = applicationContext.getBean(beanKey, DruidDataSource.class);    if (isSameDataSource(existsDataSource, entity)) {     continue;    }   }   // 組裝bean   AbstractBeanDefinition beanDefinition = getBeanDefinition(entity, beanKey);   // 注冊bean   beanFactory.registerBeanDefinition(beanKey, beanDefinition);   // 放入map中，注意一定是剛才創建bean對象   targetDataSources.put(beanKey, applicationContext.getBean(beanKey));  }  // 將創建的map對象set到 targetDataSources；  dynamicDataSource.setTargetDataSources(targetDataSources);  // 必須執行此操作，才會重新初始化AbstractRoutingDataSource 中的 resolvedDataSources，也只有這樣，動態切換才會起效  dynamicDataSource.afterPropertiesSet(); } /**  * 組裝數據源spring bean  */ private AbstractBeanDefinition getBeanDefinition(TenantConfigEntity entity, String beanKey) {  BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(DruidDataSource.class);  builder.getBeanDefinition().setAttribute("id", beanKey);  // 其他配置繼承defaultDataSource  builder.setParentName(DEFAULT_DATA_SOURCE_BEAN_KEY);  builder.setInitMethodName("init");  builder.setDestroyMethodName("close");  builder.addPropertyValue("name", beanKey);  builder.addPropertyValue("url", DataSourceUtil.getJDBCUrl(entity.getDbUrl()));  builder.addPropertyValue("username", entity.getDbUser());  builder.addPropertyValue("password", entity.getDbPassword());  builder.addPropertyValue("connectionProperties", DataSourceUtil.getConnectionProperties(entity.getDbPublicKey()));  return builder.getBeanDefinition(); } /**  * 判斷Spring容器里面的DataSource與數據庫的DataSource信息是否一致  * 備注:這里沒有判斷public_key,因為另外三個信息基本可以確定唯一了  */ private boolean isSameDataSource(DruidDataSource existsDataSource, TenantConfigEntity entity) {  boolean sameUrl = Objects.equals(existsDataSource.getUrl(), DataSourceUtil.getJDBCUrl(entity.getDbUrl()));  if (!sameUrl) {   return false;  }  boolean sameUser = Objects.equals(existsDataSource.getUsername(), entity.getDbUser());  if (!sameUser) {   return false;  }  try {   String decryptPassword = ConfigTools.decrypt(entity.getDbPublicKey(), entity.getDbPassword());   return Objects.equals(existsDataSource.getPassword(), decryptPassword);  } catch (Exception e) {   log.error("數據源密碼校驗失敗,Exception:{}", e);   return false;  } }}

<!-- 引入jdbc配置文件 --> <context:property-placeholder location="classpath:data.properties" ignore-unresolvable="true"/> <!-- 公共(默認)數據源 --> <bean id="defaultDataSource" class="com.alibaba.druid.pool.DruidDataSource"   init-method="init" destroy-method="close">  <!-- 基本屬性 url、user、password -->  <property name="url" value="${ds.jdbcUrl}" />  <property name="username" value="${ds.user}" />  <property name="password" value="${ds.password}" />  <!-- 配置初始化大小、最小、最大 -->  <property name="initialSize" value="5" />  <property name="minIdle" value="2" />  <property name="maxActive" value="10" />  <!-- 配置獲取連接等待超時的時間，單位是毫秒 -->  <property name="maxWait" value="1000" />  <!-- 配置間隔多久才進行一次檢測，檢測需要關閉的空閑連接，單位是毫秒 -->  <property name="timeBetweenEvictionRunsMillis" value="5000" />  <!-- 配置一個連接在池中最小生存的時間，單位是毫秒 -->  <property name="minEvictableIdleTimeMillis" value="240000" />  <property name="validationQuery" value="SELECT 1" />  <!--單位：秒，檢測連接是否有效的超時時間-->  <property name="validationQueryTimeout" value="60" />  <!--建議配置為true，不影響性能，并且保證安全性。申請連接的時候檢測，如果空閑時間大于timeBetweenEvictionRunsMillis，執行validationQuery檢測連接是否有效-->  <property name="testWhileIdle" value="true" />  <!--申請連接時執行validationQuery檢測連接是否有效，做了這個配置會降低性能。-->  <property name="testOnBorrow" value="true" />  <!--歸還連接時執行validationQuery檢測連接是否有效，做了這個配置會降低性能。-->  <property name="testOnReturn" value="false" />  <!--Config Filter-->  <property name="filters" value="config" />  <property name="connectionProperties" value="config.decrypt=true;config.decrypt.key=${ds.publickey}" /> </bean> <!-- 事務管理器 --> <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  <property name="dataSource" ref="multipleDataSource"/> </bean> <!--多數據源--> <bean id="multipleDataSource" class="a.b.c.DynamicDataSource">  <property name="defaultTargetDataSource" ref="defaultDataSource"/>  <property name="targetDataSources">   <map>    <entry key="defaultDataSource" value-ref="defaultDataSource"/>   </map>  </property> </bean> <!-- 注解事務管理器 --> <!--這里的order值必須大于DynamicDataSourceAspectAdvice的order值--> <tx:annotation-driven transaction-manager="txManager" order="2"/> <!-- 創建SqlSessionFactory，同時指定數據源 --> <bean id="mainSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  <property name="dataSource" ref="multipleDataSource"/> </bean> <!-- DAO接口所在包名，Spring會自動查找其下的DAO --> <bean id="mainSqlMapper" class="org.mybatis.spring.mapper.MapperScannerConfigurer">  <property name="sqlSessionFactoryBeanName" value="mainSqlSessionFactory"/>  <property name="basePackage" value="a.b.c.*.dao"/> </bean> <bean id="defaultSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  <property name="dataSource" ref="defaultDataSource"/> </bean> <bean id="defaultSqlMapper" class="org.mybatis.spring.mapper.MapperScannerConfigurer">  <property name="sqlSessionFactoryBeanName" value="defaultSqlSessionFactory"/>  <property name="basePackage" value="a.b.c.base.dal.dao"/> </bean> <!-- 其他配置省略 -->

@Slf4j@Aspect@Component@Order(1) // 請注意：這里order一定要小于tx:annotation-driven的order，即先執行DynamicDataSourceAspectAdvice切面，再執行事務切面，才能獲取到最終的數據源@EnableAspectJAutoProxy(proxyTargetClass = true)public class DynamicDataSourceAspectAdvice { @Around("execution(* a.b.c.*.controller.*.*(..))") public Object doAround(ProceedingJoinPoint jp) throws Throwable {  ServletRequestAttributes sra = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();  HttpServletRequest request = sra.getRequest();  HttpServletResponse response = sra.getResponse();  String tenantKey = request.getHeader("tenant");  // 前端必須傳入tenant header, 否則返回400  if (!StringUtils.hasText(tenantKey)) {   WebUtils.toHttp(response).sendError(HttpServletResponse.SC_BAD_REQUEST);   return null;  }  log.info("當前租戶key:{}", tenantKey);  DataSourceContextHolder.setDataSourceKey(tenantKey);  Object result = jp.proceed();  DataSourceContextHolder.clearDataSourceKey();  return result; }}