Headless CMS for Java

import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

import java.io.IOException;

public class GraphQLMutationExample {

    public static void main(String[] args) throws IOException {
        OkHttpClient client = new OkHttpClient();

        String graphqlMutation = "{"
            + "\"query\":\"mutation CreateProduct($input: ProductInput!) {"
            + "  createProduct(input: $input) {"
            + "    id"
            + "    name"
            + "    description"
            + "  }"
            + "}\","
            + "\"variables\":{\"input\":{"
            + "  \"name\":\"New Product\","
            + "  \"description\":\"This is a new product.\","
            + "  \"slug\":\"new-product\","
            + "  \"availability\":\"IN_STOCK\","
            + "  \"imageUrl\":\"http://example.com/product.jpg\""
            + "}}"
            + "}";
        String url = "https://management.hygraph.com/graphql";

        RequestBody body = RequestBody.create(
                graphqlMutation,
                MediaType.get("application/json; charset=utf-8")
        );

        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();

        try (Response response = client.newCall(request).execute()) {
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

            System.out.println(response.body().string());
        }
    }
}