Add netty websocket game server with web client

src/main/java/com/gameserver/GameMessage.java

@@ -0,0 +1,33 @@
+package com.gameserver;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class GameMessage {
+    private final String type;
+    private final String payload;
+
+    @JsonCreator
+    public GameMessage(
+            @JsonProperty("type") String type,
+            @JsonProperty("payload") String payload) {
+        this.type = type;
+        this.payload = payload;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public String getPayload() {
+        return payload;
+    }
+
+    @Override
+    public String toString() {
+        return "GameMessage{" +
+                "type='" + type + '\'' +
+                ", payload='" + payload + '\'' +
+                '}';
+    }
+}