[dubbo] 02/03: add back instance metadata listener

[li...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

liujun pushed a commit to branch 3.0-k8s
in repository https://gitbox.apache.org/repos/asf/dubbo.git

commit 780fe21e6897c24b3003d66845c9c80feb9d4964
Author: ken.lj <ke...@gmail.com>
AuthorDate: Fri Jan 15 17:19:55 2021 +0800

    add back instance metadata listener
---
 .../metadata/InstanceMetadataChangedListener.java  | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/InstanceMetadataChangedListener.java b/dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/InstanceMetadataChangedListener.java
new file mode 100644
index 0000000..5536e53
--- /dev/null
+++ b/dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/InstanceMetadataChangedListener.java
@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.metadata;
+
+public interface InstanceMetadataChangedListener {
+    /**
+     * Call when metadata in provider side update <p/>
+     * Used to notify consumer to update metadata of ServiceInstance
+     *
+     * @param metadata latest metadata
+     */
+    void onEvent(String metadata);
+
+    /**
+     * Echo test
+     * Used to check consumer still online
+     */
+    default String echo(String msg) {
+        return msg;
+    }
+}