feat: add JSONFetcher to fetch a JSON with URL

src/main/java/eirb/pg203/utils/JSONFetcher.java

@@ -0,0 +1,25 @@
+package eirb.pg203.utils;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import org.json.JSONObject;
+
+public class JSONFetcher {
+  public static JSONObject fetch(URL url) throws IOException {
+    StringBuilder result = new StringBuilder();
+    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+    conn.setRequestMethod("GET");
+    try (BufferedReader reader = new BufferedReader(
+        new InputStreamReader(conn.getInputStream()))) {
+      for (String line; (line = reader.readLine()) != null; ) {
+        result.append(line);
+      }
+    }
+
+    return new JSONObject(result.toString());
+  }
+}