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README.md

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+RPC-Netty project
+
+使用netty作为主要的IO框架，实现基于zookeeper、netty、jackson、序列化框架实现的RPC demo.
+架构设计:
+
+## 1、服务注册和服务信息获取
+
+```mermaid
+graph TB
+id1(service provider)--注册服务-->id2(registry)
+id3(remote caller)--请求调用-->id2
+```
+
+### 1.服务数据结构
+
+通过zookeeper存放服务信息和多个server信息（二进制或者json串），服务提供格式如下：
+
+```java
+@Data
+public class RpcProtocol implements Serializable {
+    public static final long serialVersionUID = -1102180003395190700L;
+    private String host;			//server host
+    private int port;				//server host
+    private List<RpcServiceInfo> serviceInfos;	//service infos
+}
+```
+
+而`RpcServiceInfo`实现主要的`service class`信息和`method`信息：
+
+```java
+@Data
+public class RpcServiceInfo implements Serializable {
+    private String serviceName;
+    private String version;
+}
+```
+
+### 2.服务信息json和反json
+
+并且使用json串实现注册中心的注册行为和获取服务信息的方法：
+
+```java
+	/**
+     *
+     * @return: json String for serialize
+     */
+    public String toJson(){
+        String json = JsonUtil.objectToJson(this);
+        RpcProtocol obj = JsonUtil.jsonToObject (json, RpcProtocol.class);
+        return json;
+    }
+    /**
+     * json string to RpcProtocol
+     * @param json
+     * @return RpcProtocol instance
+     */
+    public static RpcProtocol fromJson(String json){
+        return JsonUtil.jsonToObject(json, RpcProtocol.class);
+    }
+```
+
+同时jsonUtil实现如下：
+
+```java
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.*;
+public class JsonUtil {
+    public static ObjectMapper  objectMapper= new ObjectMapper();
+    static {
+        //configure ObjectMapper
+        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+        objectMapper.setDateFormat(dateFormat);
+        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+        objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
+        objectMapper.configure(JsonGenerator.Feature.AUTO_CLOSE_TARGET, false);
+        objectMapper.configure(JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT, false);
+        //objectMapper.configure(JsonGenerator.Feature.AUTO_CLOSE_TARGET, false);
+        objectMapper.disable(SerializationFeature.FLUSH_AFTER_WRITE_VALUE);
+        objectMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
+        objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
+        objectMapper.configure(JsonParser.Feature.IGNORE_UNDEFINED,true);
+        objectMapper.disable(SerializationFeature.CLOSE_CLOSEABLE);
+    }
+    public static <T> byte[] serialize(T obj){
+        byte[] bytes = new byte[0];
+        try {
+            bytes = objectMapper.writeValueAsBytes(obj);
+        }catch (JsonProcessingException e){
+            throw new IllegalStateException(e.getMessage(),e);
+        }
+        return bytes;
+    }
+    public static <T> T deserialize(byte[] bytes, Class<T> clazz){
+        T obj = null;
+        try {
+            obj = objectMapper.readValue(bytes, clazz);
+        }catch (IOException e){
+            throw new IllegalStateException(e.getMessage(),e);
+        }
+        return obj;
+    }
+    public static <T> T jsonToObject(String json, Class<T> clazz){
+        T obj = null;
+        JavaType javaType = objectMapper.getTypeFactory().constructType(clazz);
+        try {
+            obj = objectMapper.readValue(json, javaType);
+        } catch (IOException e) {
+           throw new IllegalStateException(e.getMessage(), e);
+        }
+        return obj;
+    }
+
+    public static <T> T jsonToObjectList(String json,
+                                               Class<?> collectionClass, Class<?>... elementClass) {
+        T obj = null;
+        JavaType javaType = objectMapper.getTypeFactory().constructParametricType(
+                collectionClass, elementClass);
+        try {
+            obj = objectMapper.readValue(json, javaType);
+        } catch (IOException e) {
+            throw new IllegalStateException(e.getMessage(), e);
+        }
+        return obj;
+    }
+    public static <T> T jsonToObjectHashMap(String json,
+                                                  Class<?> keyClass, Class<?> valueClass) {
+        T obj = null;
+        JavaType javaType = objectMapper.getTypeFactory().constructParametricType(HashMap.class, keyClass, valueClass);
+        try {
+            obj = objectMapper.readValue(json, javaType);
+        } catch (IOException e) {
+            throw new IllegalStateException(e.getMessage(), e);
+        }
+        return obj;
+    }
+    public static String objectToJson(Object o) {
+        String json = "";
+        try {
+            json = objectMapper.writeValueAsString(o);
+        } catch (IOException e) {
+            throw new IllegalStateException(e.getMessage(), e);
+        }
+        return json;
+    }
+}
+```
+
+### 3.服务注册发现
+
+使用jackson实现数据绑定，序列化和反序列化`RpcProtocol`,同样的使用该数据的有服务发现`ServiceDiscorvery`模块，反序列化对象依旧是`RpcProtocol`.
+
+```java
+public class ServiceDiscovery {
+    public static final Logger logger = LoggerFactory.getLogger(ServiceDiscovery.class);
+    //service registry client
+    //in this demo i use zookeeper cutatorclient
+    //private CuratorClient client;
+    private void discoveryService();    //发现服务
+    private void getServiceAndUpdateServer();     //实现服务的更新
+    private void updateConnectedServer(List<RpcProtocol> protocols);
+}
+```
+
+同样的服务注册也是基于`RpcProtocol`的序列化和反序列化实现：
+
+```java
+public class ServiceRegistry {
+    private static final Logger logger = LoggerFactory.getLogger(ServiceRegistry.class);
+    // zookeeper client
+    //private CuratorClient client;
+    // zookeeper path
+    private List<String> pathList = new ArrayList<String>();
+    public ServiceRegistry(CuratorClient client) {
+        this.client = client;
+    }
+    public void registryService(final String host, final int port, final Map<String, Object> serviceMap);
+    public void unregisterService();
+}
+```
+
+## 2、远程调用实现
+
+//TODO: 完成远程的实现编写

src/main/java/com/lixiande/common/protocol/RpcProtocol.java

@@ -20,9 +20,9 @@
 **/
 public class RpcProtocol implements Serializable {
     public static final long serialVersionUID = -1102180003395190700L;
-    private String host;
-    private int port;
-    private List<RpcServiceInfo> serviceInfos;
+    private String host;            //server host
+    private int port;               //server port
+    private List<RpcServiceInfo> serviceInfos;  //service infos
 
     /**
      *