GraphQL Client in java

GraphQLClient.java

package org.example;

//  <dependency>
//      <groupId>org.apache.httpcomponents</groupId>
//      <artifactId>httpclient</artifactId>
//      <version>4.5.14</version>
//  </dependency>
//  <dependency>
//      <groupId>org.json</groupId>
//      <artifactId>json</artifactId>
//      <version>20230618</version>
//  </dependency>

import org.apache.http.HttpEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;

public class GraphQLClient {

    private final String endpoint;
    private final String username;
    private final String password;

    public GraphQLClient(String endpoint, String username, String password) {
        this.endpoint = endpoint;
        this.username = username;
        this.password = password;
    }

    private CloseableHttpClient getHTTPClient() {
        return HttpClients.custom()
                .setDefaultCredentialsProvider(getBasicAuth(username, password))
                .build();
    }

    private HttpPost createHTTPRequest() {
        HttpPost request = new HttpPost(endpoint);
        request.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
        return request;
    }

    private String prepareQuery(String query) {
        return new JSONObject()
                .put("query", query)
                .toString();
    }

    private void validateHTTPResponse(HttpResponse response) {
        if (response.getStatusLine().getStatusCode() != 200) {
            throw new RuntimeException("Failed : HTTP error code : " +
                    response.getStatusLine().getStatusCode() +
                    " " + response.getStatusLine().getReasonPhrase());
        }
    }

    private void validateJSONResponse(JSONObject response) {
        if (response.has("errors")) {
            throw new RuntimeException("Failed : GraphQL error : " +
                    response.getJSONArray("errors").toString());
        }
    }

    private static CredentialsProvider getBasicAuth(String username, String password) {
        CredentialsProvider provider = new BasicCredentialsProvider();
        provider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));
        return provider;
    }

    public JSONObject query(String query) throws Exception {

        // prepare
        CloseableHttpClient client = getHTTPClient();
        HttpPost request = createHTTPRequest();
        request.setEntity(new StringEntity(prepareQuery(query), "UTF-8"));

        // execute
        HttpResponse response = client.execute(request);

        // validate
        validateHTTPResponse(response);

        // get response
        HttpEntity entity = response.getEntity();

        // prepare JSON response
        JSONObject jsonResponse = new JSONObject(EntityUtils.toString(entity));
        validateJSONResponse(jsonResponse);

        // close client
        client.close();

        return jsonResponse;
    }
}