使用java格式的Graphql查询发送HTTP POST请求

我想在monday.com上创建一个票证。我编写了HTTP方法，该方法在特定的星期一服务器上进行POST调用，并作为参数传递graphql查询。但不幸的是，没有成功，我认为我以错误的方式传递了查询参数，但我无法准确地判断我到底做错了什么

import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;



public class Monday {

    static int id = 1249501957;
    static String token = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
    static String query = "mutation {\n"
            + "    create_item(item_name:\"heyyyyyyy\", board_id:" + id + "){\n"
            + "        id\n"
            + "    }\n"
            + "}";
    static String targetURL = "https://levank707.monday.com/projects";



    public static void main(String[] args) throws Exception {

        executePost(targetURL,query);
        
    }

        public static String executePost(String targetURL, String query) {
              HttpURLConnection connection = null;

              try {
                //Create connection
                URL url = new URL(targetURL);
                connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("POST");
                connection.setRequestProperty("Content-Type", 
                    "application/graphql");

                connection.setRequestProperty("Content-Length", 
                    Integer.toString(query.getBytes().length));
                connection.setRequestProperty("Authorization",token );  

                connection.setUseCaches(false);
                connection.setDoOutput(true);

                //Send request
                DataOutputStream wr = new DataOutputStream (
                    connection.getOutputStream());
                wr.writeBytes(query);
                wr.close();

                //Get Response  
                InputStream is = connection.getInputStream();
                BufferedReader rd = new BufferedReader(new InputStreamReader(is));
                StringBuilder response = new StringBuilder(); // or StringBuffer if Java version 5+
                String line;
                while ((line = rd.readLine()) != null) {
                  response.append(line);
                  response.append('\r');
                }
                rd.close();
                return response.toString();
              } catch (Exception e) {
                e.printStackTrace();
                return null;
              } finally {
                if (connection != null) {
                  connection.disconnect();
                }
              }

        }}

---

你说不成功是什么意思？任何错误消息或状态代码？。我得到了这样的结果：/通常正文的格式是“{”query:“mutation{…}\n}\n}”