update docs

docs/zh/core/multi-datasource.md

@@ -198,5 +198,21 @@ HikariDataSource newDataSource = new HikariDataSource();
 flexDataSource.addDataSource("newKey", newDataSource);
 ```
 
-> 需要注意的是：通过 FlexGlobalConfig 去获取 FlexDataSource 时，需等待应用完全启动成功后，才能正常获取 FlexDataSource，
-> 否则将会得到 null 值。
+**需要注意的是：** 通过 FlexGlobalConfig 去获取 FlexDataSource 时，需等待应用完全启动成功后，才能正常获取 FlexDataSource，
+否则将会得到 null 值。
+
+Spring 用户可以通过 `ApplicationListener` 去监听 `ContextRefreshedEvent` 事件，然后再去添加新的数据源，如下代码所示：
+
+```java
+public class DataSourceInitListener implements ApplicationListener<ContextRefreshedEvent> {
+
+    @Override
+    public void onApplicationEvent(ContextRefreshedEvent event) {
+        FlexDataSource dataSource = (FlexDataSource) FlexGlobalConfig.getDefaultConfig()
+                .getConfiguration().getEnvironment().getDataSource();
+
+        dataSource.addDataSource("....", new DruidDataSource("..."));
+    }
+
+}
+```

mybatis-flex-test/mybatis-flex-spring-boot-test/src/main/java/com/mybatisflex/test/DataSourceInitListener.java

@@ -0,0 +1,20 @@
+package com.mybatisflex.test;
+
+import com.mybatisflex.core.FlexGlobalConfig;
+import com.mybatisflex.core.datasource.FlexDataSource;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.stereotype.Component;
+
+@Component
+public class DataSourceInitListener implements ApplicationListener<ContextRefreshedEvent> {
+
+    @Override
+    public void onApplicationEvent(ContextRefreshedEvent event) {
+        FlexDataSource dataSource = (FlexDataSource) FlexGlobalConfig.getDefaultConfig()
+                .getConfiguration().getEnvironment().getDataSource();
+
+        System.out.println("onApplicationEvent>>>> datasource:" + dataSource);
+    }
+
+}