初始提交，实现WebSocket聊天室基本功能

src/main/java/cn/airnan/dg/utils/CommonResponse.java

@@ -0,0 +1,24 @@
+package cn.airnan.dg.utils;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class CommonResponse<T> {
+    private int code;
+    private String msg;
+    private T data;
+
+    public static <T> CommonResponse<T> success(T data) {
+        return new CommonResponse<T>(0, "success", data);
+    }
+
+    public static <T> CommonResponse<T> success() {
+        return new CommonResponse<T>(0, "success", null);
+    }
+
+    public static <T> CommonResponse<T> error(String msg) {
+        return new CommonResponse<T>(1, msg, null);
+    }
+}