WIP: compatible with JDK1.6

broker/src/main/java/org/apache/rocketmq/broker/processor/AbstractSendMessageProcessor.java

@@ -49,11 +49,12 @@ import org.apache.rocketmq.logging.InternalLogger;
 import org.apache.rocketmq.logging.InternalLoggerFactory;
 import org.apache.rocketmq.remoting.common.RemotingHelper;
 import org.apache.rocketmq.remoting.exception.RemotingCommandException;
+import org.apache.rocketmq.remoting.netty.AsyncNettyRequestProcessor;
 import org.apache.rocketmq.remoting.netty.NettyRequestProcessor;
 import org.apache.rocketmq.remoting.protocol.RemotingCommand;
 import org.apache.rocketmq.store.MessageExtBrokerInner;
 
-public abstract class AbstractSendMessageProcessor implements NettyRequestProcessor {
+public abstract class AbstractSendMessageProcessor extends AsyncNettyRequestProcessor implements NettyRequestProcessor {
     protected static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME);
 
     protected final static int DLQ_NUMS_PER_GROUP = 1;

broker/src/main/java/org/apache/rocketmq/broker/processor/AdminBrokerProcessor.java

@@ -118,6 +118,7 @@ import org.apache.rocketmq.filter.util.BitsArray;
 import org.apache.rocketmq.remoting.common.RemotingHelper;
 import org.apache.rocketmq.remoting.exception.RemotingCommandException;
 import org.apache.rocketmq.remoting.exception.RemotingTimeoutException;
+import org.apache.rocketmq.remoting.netty.AsyncNettyRequestProcessor;
 import org.apache.rocketmq.remoting.netty.NettyRequestProcessor;
 import org.apache.rocketmq.remoting.protocol.LanguageCode;
 import org.apache.rocketmq.remoting.protocol.RemotingCommand;
@@ -132,7 +133,7 @@ import org.apache.rocketmq.store.PutMessageResult;
 import org.apache.rocketmq.store.PutMessageStatus;
 import org.apache.rocketmq.store.SelectMappedBufferResult;
 
-public class AdminBrokerProcessor implements NettyRequestProcessor {
+public class AdminBrokerProcessor extends AsyncNettyRequestProcessor implements NettyRequestProcessor {
     private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME);
     private final BrokerController brokerController;
 

broker/src/main/java/org/apache/rocketmq/broker/processor/SendMessageProcessor.java

@@ -50,6 +50,7 @@ import org.apache.rocketmq.common.sysflag.MessageSysFlag;
 import org.apache.rocketmq.common.sysflag.TopicSysFlag;
 import org.apache.rocketmq.remoting.exception.RemotingCommandException;
 import org.apache.rocketmq.remoting.netty.NettyRequestProcessor;
+import org.apache.rocketmq.remoting.netty.RemotingResponseCallback;
 import org.apache.rocketmq.remoting.protocol.RemotingCommand;
 import org.apache.rocketmq.store.MessageExtBrokerInner;
 import org.apache.rocketmq.store.PutMessageResult;
@@ -77,6 +78,10 @@ public class SendMessageProcessor extends AbstractSendMessageProcessor implement
     }
 
     @Override
+    public void asyncProcessRequest(ChannelHandlerContext ctx, RemotingCommand request, RemotingResponseCallback responseCallback) throws Exception {
+        asyncProcessRequest(ctx, request).thenAccept(responseCallback::callback);
+    }
+
     public CompletableFuture<RemotingCommand> asyncProcessRequest(ChannelHandlerContext ctx,
                                                                   RemotingCommand request) throws RemotingCommandException {
         final SendMessageContext mqtraceContext;

remoting/pom.xml

@@ -28,8 +28,8 @@
     <name>rocketmq-remoting ${project.version}</name>
 
     <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.6</maven.compiler.source>
+        <maven.compiler.target>1.6</maven.compiler.target>
     </properties>
 
     <dependencies>

remoting/src/main/java/org/apache/rocketmq/remoting/netty/AsyncNettyRequestProcessor.java

+package org.apache.rocketmq.remoting.netty;
+
+import io.netty.channel.ChannelHandlerContext;
+import org.apache.rocketmq.remoting.protocol.RemotingCommand;
+
+public abstract class AsyncNettyRequestProcessor implements NettyRequestProcessor {
+
+    public void asyncProcessRequest(ChannelHandlerContext ctx, RemotingCommand request, RemotingResponseCallback responseCallback) throws Exception {
+        RemotingCommand response = processRequest(ctx, request);
+        responseCallback.callback(response);
+    }
+}

remoting/src/main/java/org/apache/rocketmq/remoting/netty/NettyRemotingAbstract.java

@@ -29,7 +29,6 @@ import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map.Entry;
-import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutorService;
@@ -201,25 +200,28 @@ public abstract class NettyRemotingAbstract {
                 public void run() {
                     try {
                         doBeforeRpcHooks(RemotingHelper.parseChannelRemoteAddr(ctx.channel()), cmd);
-                        CompletableFuture<RemotingCommand> responseFuture = pair.getObject1().asyncProcessRequest(ctx, cmd);
-                        responseFuture.thenAccept((r) -> {
-                            doAfterRpcHooks(RemotingHelper.parseChannelRemoteAddr(ctx.channel()), cmd, r);
+                        AsyncNettyRequestProcessor processor = (AsyncNettyRequestProcessor)pair.getObject1();
+                        final RemotingResponseCallback callback = new RemotingResponseCallback() {
+                            @Override
+                            public void callback(RemotingCommand response) {
+                                doAfterRpcHooks(RemotingHelper.parseChannelRemoteAddr(ctx.channel()), cmd, response);
                                 if (!cmd.isOnewayRPC()) {
-                                if (r != null) {
-                                    r.setOpaque(opaque);
-                                    r.markResponseType();
+                                    if (response != null) {
+                                        response.setOpaque(opaque);
+                                        response.markResponseType();
                                         try {
-                                        ctx.writeAndFlush(r);
+                                            ctx.writeAndFlush(response);
                                         } catch (Throwable e) {
                                             log.error("process request over, but response failed", e);
                                             log.error(cmd.toString());
-                                        log.error(r.toString());
+                                            log.error(response.toString());
                                         }
                                     } else {
-
                                     }
                                 }
-                        });
+                            }
+                        };
+                        processor.asyncProcessRequest(ctx, cmd, callback);
                     } catch (Throwable e) {
                         log.error("process request exception", e);
                         log.error(cmd.toString());

remoting/src/main/java/org/apache/rocketmq/remoting/netty/NettyRequestProcessor.java

@@ -19,8 +19,6 @@ package org.apache.rocketmq.remoting.netty;
 import io.netty.channel.ChannelHandlerContext;
 import org.apache.rocketmq.remoting.protocol.RemotingCommand;
 
-import java.util.concurrent.CompletableFuture;
-
 /**
  * Common remoting command processor
  */
@@ -30,8 +28,4 @@ public interface NettyRequestProcessor {
 
     boolean rejectRequest();
 
-    default CompletableFuture<RemotingCommand> asyncProcessRequest(ChannelHandlerContext ctx, RemotingCommand request)
-        throws Exception {
-        return CompletableFuture.completedFuture(processRequest(ctx, request));
-    }
 }

remoting/src/main/java/org/apache/rocketmq/remoting/netty/RemotingResponseCallback.java

+package org.apache.rocketmq.remoting.netty;
+
+import org.apache.rocketmq.remoting.protocol.RemotingCommand;
+
+public interface RemotingResponseCallback {
+    void callback(RemotingCommand response);
+}