diff --git a/dami/src/main/java/org/noear/dami/bus/impl/RoutingTag.java b/dami/src/main/java/org/noear/dami/bus/impl/RoutingTag.java
index 0b566ac7f5079abb32e973c519c6193007cadfe6..c4c2b44bd5e8a1404ac9900ec80e748541596818 100644
--- a/dami/src/main/java/org/noear/dami/bus/impl/RoutingTag.java
+++ b/dami/src/main/java/org/noear/dami/bus/impl/RoutingTag.java
@@ -4,6 +4,7 @@ import org.noear.dami.bus.Payload;
 import org.noear.dami.bus.TopicListener;
 
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * 监听路由记录（tag 模式）
@@ -48,36 +49,26 @@ public class RoutingTag<C, R> extends Routing<C, R> {
 
         boolean topicMatch = exprList.get(0).equals(this.topic);
 
-        boolean hasTags = tags.isEmpty() || sendTags.isEmpty();
-        //发送和监听一方有tags则需要匹配
-        boolean tagMatch = hasTags || sendTags.stream().anyMatch(this.tags::contains);
+        boolean notHasTags = tags.isEmpty() || sendTags.isEmpty();
+        //发送和监听双方都有tags则需要匹配
+        boolean tagMatch = notHasTags || sendTags.stream().anyMatch(this.tags::contains);
 
         return topicMatch && tagMatch;
     }
 
     static class TopicTags {
-        private static Map<String, List<String>> cached = new HashMap<>();
+        private static final Map<String, List<String>> cached = new ConcurrentHashMap<>();
 
         /**
          * 获取 TopicTags
          */
         public static List<String> get(String expr) {
-            List<String> tmp = cached.get(expr);
-            if (tmp == null) {
-                synchronized (TopicTags.class) {
-                    tmp = cached.get(expr);
-                    if (tmp == null) {
-                        tmp = parse(expr);
-                        cached.put(expr, tmp);
-                    }
-                }
-            }
-
-            return tmp;
+            return cached.computeIfAbsent(expr, TopicTags::parse);
         }
 
         /**
          * 解析表达式
+         * @return List<String> 第一个元素为topic，剩下的为tag
          */
         private static List<String> parse(String expr) {
             List<String> parseList = new ArrayList<>();
@@ -88,6 +79,7 @@ public class RoutingTag<C, R> extends Routing<C, R> {
                 return parseList;
             }
 
+            //topic:tag1,tag2,tag3 以 : 切割为两部分
             String[] topicSplit = expr.split(":", 2);
             parseList.add(topicSplit[0]);
 
@@ -95,7 +87,7 @@ public class RoutingTag<C, R> extends Routing<C, R> {
             if (topicSplit[1].isEmpty()) {
                 return parseList;
             }
-
+            //tag1,tag2,tag3 以 , 切割数组作为tags
             String[] tagSplit = topicSplit[1].split(",");
             parseList.addAll(Arrays.asList(tagSplit));
 
diff --git a/dami/src/test/java/features/demo15_patterned/Demo15_tag.java b/dami/src/test/java/features/demo15_patterned/Demo15_tag.java
index 83ecb7a32dc577d0bcd1b72d6cd08ff70f66ce8b..fc4c331e76930d25d1c0f30d6a22f607677dcb5c 100644
--- a/dami/src/test/java/features/demo15_patterned/Demo15_tag.java
+++ b/dami/src/test/java/features/demo15_patterned/Demo15_tag.java
@@ -17,6 +17,9 @@ public class Demo15_tag {
 
         AtomicInteger testObserver = new AtomicInteger();
 
+        //":"前为主题，后按 "," 号分割作为tag
+        //发送事件的tag只要有一个存在于监听的tag里面则会匹配 (多对多)
+
         //拦截1
         busStr.listen("demo:a,b", (payload) -> {
             System.err.println(payload);
@@ -29,7 +32,8 @@ public class Demo15_tag {
         });
 
         //发送事件
-        //发送的事件的tag只有有一个存在于监听的tag里面则会匹配
+
+        //发送和监听双方一方没有tags则无需匹配
         //2
         busStr.send("demo", "world");
         //1