fix problems

src/main/java/com/orhon/smartcampus/material/cloud/Api.java

+package com.orhon.smartcampus.material.cloud;
+
+
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.serializer.SerializerFeature;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.*;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+@Component
+public class Api {
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+
+    public ResponseEntity<Map> buildGqlQuery(String query){
+        Map<String , Object> data = new HashMap<>();
+        data.put("query" , query);
+        data.put("operationName" , null);
+        data.put("variables" , null);
+        String payload = JSON.toJSONString(data , SerializerFeature.WriteMapNullValue);
+        HttpHeaders headers = new HttpHeaders();
+        String graphqlMapping = "http://smartcampus-base/graphql";
+        HttpEntity<Object> request = this.forJson(payload , headers);
+        return restTemplate.exchange(graphqlMapping, HttpMethod.POST, request, Map.class);
+    }
+
+
+    private HttpEntity<Object> forJson(String json, HttpHeaders headers) {
+        headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
+        return new HttpEntity<>(json, headers);
+    }
+
+}
+
+
+