Validator that validate that the type of the field/returned type of the method is instance of "PaginatedData"

Author: guy120494

src/main/java/graphql/annotations/connection/ConnectionTypeValidator.java

@@ -0,0 +1,35 @@
+/**
+ * Copyright 2016 Yurii Rashkovskii
+ *
+ * Licensed 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
+ */
+package graphql.annotations.connection;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+public class ConnectionTypeValidator {
+
+    public void validate(AccessibleObject field) {
+        if(field instanceof Field) {
+            if(!PaginatedData.class.isAssignableFrom(((Field)field).getType())) {
+                throw new GraphQLConnectionException(((Field) field).getName() + " type must be PaginatedData");
+            }
+        }
+        else {
+            if(!PaginatedData.class.isAssignableFrom(((Method)field).getReturnType())){
+                throw new GraphQLConnectionException(((Method) field).getName() + " return type must be PaginatedData");
+            }
+        }
+    }
+}