Refactor: Change bidirectional association to unidirectional association

CounterServer: class participates in a cyclic dependency. The participating classes in the cycle are: CounterServiceImpl; CounterServer

Author: JAYDIPSINH27

jraft-example/src/main/java/com/alipay/sofa/jraft/example/counter/CounterServer.java

@@ -46,7 +46,8 @@ public class CounterServer {
     private CounterStateMachine fsm;
 
     public CounterServer(final String dataPath, final String groupId, final PeerId serverId,
-                         final NodeOptions nodeOptions) throws IOException {
+                         final NodeOptions nodeOptions, final CounterServiceProvider counterServiceProvider)
+                                                                                                            throws IOException {
         // init raft data path, it contains log,meta,snapshot
         FileUtils.forceMkdir(new File(dataPath));
 
@@ -57,7 +58,7 @@ public CounterServer(final String dataPath, final String groupId, final PeerId s
         CounterGrpcHelper.setRpcServer(rpcServer);
 
         // register business processor
-        CounterService counterService = new CounterServiceImpl(this);
+        CounterService counterService = counterServiceProvider.getCounterService();
         rpcServer.registerProcessor(new GetValueRequestProcessor(counterService));
         rpcServer.registerProcessor(new IncrementAndGetRequestProcessor(counterService));
         // init state machine
@@ -116,6 +117,8 @@ public static void main(final String[] args) throws IOException {
         final String serverIdStr = args[2];
         final String initConfStr = args[3];
 
+        CounterServiceProvider counterServiceProvider = new CounterServiceImpl(null);
+
         final NodeOptions nodeOptions = new NodeOptions();
         // for test, modify some params
         // set election timeout to 1s
@@ -137,7 +140,9 @@ public static void main(final String[] args) throws IOException {
         nodeOptions.setInitialConf(initConf);
 
         // start raft server
-        final CounterServer counterServer = new CounterServer(dataPath, groupId, serverId, nodeOptions);
+        final CounterServer counterServer = new CounterServer(dataPath, groupId, serverId, nodeOptions,
+            counterServiceProvider);
+        //        ((CounterServiceImpl) counterServiceProvider).counterServer = counterServer;
         System.out.println("Started counter server at port:"
                            + counterServer.getNode().getNodeId().getPeerId().getPort());
         // GrpcServer need block to prevent process exit

jraft-example/src/main/java/com/alipay/sofa/jraft/example/counter/CounterServiceImpl.java

@@ -36,7 +36,7 @@
 /**
  * @author likun (saimu.msm@antfin.com)
  */
-public class CounterServiceImpl implements CounterService {
+public class CounterServiceImpl implements CounterService, CounterServiceProvider {
     private static final Logger LOG = LoggerFactory.getLogger(CounterServiceImpl.class);
 
     private final CounterServer counterServer;
@@ -47,6 +47,11 @@ public CounterServiceImpl(CounterServer counterServer) {
         this.readIndexExecutor = createReadIndexExecutor();
     }
 
+    @Override
+    public CounterService getCounterService() {
+        return this;
+    }
+
     private Executor createReadIndexExecutor() {
         final StoreEngineOptions opts = new StoreEngineOptions();
         return StoreEngineHelper.createReadIndexExecutor(opts.getReadIndexCoreThreads());

jraft-example/src/main/java/com/alipay/sofa/jraft/example/counter/CounterServiceProvider.java

@@ -0,0 +1,21 @@
+/*
+ * 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 com.alipay.sofa.jraft.example.counter;
+
+public interface CounterServiceProvider {
+    CounterService getCounterService();
+}