Add NamespaceRpcHook

client/src/main/java/org/apache/rocketmq/client/impl/MQClientAPIImpl.java

@@ -53,6 +53,7 @@
 import org.apache.rocketmq.client.producer.SendCallback;
 import org.apache.rocketmq.client.producer.SendResult;
 import org.apache.rocketmq.client.producer.SendStatus;
+import org.apache.rocketmq.client.rpchook.NamespaceRpcHook;
 import org.apache.rocketmq.common.BoundaryType;
 import org.apache.rocketmq.common.MQVersion;
 import org.apache.rocketmq.common.MixAll;
@@ -257,6 +258,7 @@ public MQClientAPIImpl(final NettyClientConfig nettyClientConfig,
         this.remotingClient = new NettyRemotingClient(nettyClientConfig, channelEventListener);
         this.clientRemotingProcessor = clientRemotingProcessor;
 
+        this.remotingClient.registerRPCHook(new NamespaceRpcHook(clientConfig));
         // Inject stream rpc hook first to make reserve field signature
         if (clientConfig.isEnableStreamRequestType()) {
             this.remotingClient.registerRPCHook(new StreamTypeRPCHook());

client/src/main/java/org/apache/rocketmq/client/rpchook/NamespaceRpcHook.java

@@ -0,0 +1,51 @@
+/*
+ * 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.rocketmq.client.rpchook;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.rocketmq.client.ClientConfig;
+import org.apache.rocketmq.remoting.CommandCustomHeader;
+import org.apache.rocketmq.remoting.RPCHook;
+import org.apache.rocketmq.remoting.protocol.RemotingCommand;
+import org.apache.rocketmq.remoting.rpc.RpcRequestHeader;
+
+public class NamespaceRpcHook implements RPCHook {
+    private final ClientConfig clientConfig;
+
+    public NamespaceRpcHook(ClientConfig clientConfig) {
+        this.clientConfig = clientConfig;
+    }
+
+    @Override
+    public void doBeforeRequest(String remoteAddr, RemotingCommand request) {
+        CommandCustomHeader customHeader = request.readCustomHeader();
+        if (customHeader instanceof RpcRequestHeader) {
+            RpcRequestHeader requestHeader = (RpcRequestHeader) customHeader;
+            if (StringUtils.isNotEmpty(clientConfig.getNamespaceV2())) {
+                requestHeader.setNamespaced(true);
+                requestHeader.setNamespace(clientConfig.getNamespaceV2());
+            }
+        }
+    }
+
+    @Override
+    public void doAfterResponse(String remoteAddr, RemotingCommand request,
+        RemotingCommand response) {
+
+    }
+}