完善返回值

src/main/java/cn/lihongjie/coal/config/RResponseBodyAdvice.java

@@ -29,6 +29,11 @@ public class RResponseBodyAdvice implements ResponseBodyAdvice<Object> {
         if (!selectedContentType.includes(MediaType.APPLICATION_JSON)) {
             return body;
         }
+
+        if (body == null) {
+            return R.success();
+        }
+
         if (body instanceof byte[]) {
             return body;
         }

src/main/java/cn/lihongjie/coal/dto/R.java

@@ -33,6 +33,10 @@ public class R<T> {
     }
 
 
+    public static <T> R<T> success() {
+        return success(null);
+    }
+
     public static <T> R<T> success(T data) {
         return create(data, "ok", "");
     }