style: 属性 dsCache 放在类的开始位置。

mybatis-flex-spring/src/main/java/com/mybatisflex/spring/datasource/DataSourceInterceptor.java

@@ -36,6 +36,11 @@ import java.util.concurrent.ConcurrentHashMap;
  */
 public class DataSourceInterceptor implements MethodInterceptor {
 
+    /**
+     * 缓存方法对应的数据源。
+     */
+    private final Map<Object, String> dsCache = new ConcurrentHashMap<>();
+
     @Override
     public Object invoke(MethodInvocation invocation) throws Throwable {
 
@@ -57,11 +62,6 @@ public class DataSourceInterceptor implements MethodInterceptor {
         }
     }
 
-    /**
-     * 缓存方法对应的数据源。
-     */
-    private final Map<Object, String> dsCache = new ConcurrentHashMap<>();
-
     private String findDataSourceKey(Method method, Class<?> targetClass) {
         Object cacheKey = new MethodClassKey(method, targetClass);
         String dsKey = this.dsCache.get(cacheKey);