How to catch an http GET replay using Httpurlconnection java.net?

Question

I have the following class:

package com.akamai.edgegrid.auth;

import java.io.*;
import java.net.*;

public class C {

   public static String getHTML(String urlToRead) throws Exception {
      StringBuilder result = new StringBuilder();
      URL url = new URL(urlToRead);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setRequestMethod("GET");
      conn.setRequestProperty("Accept-Charset", "UTF-8");
      conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
      conn.setRequestProperty("Host", "akab-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.luna.akamaiapis.net");
      conn.addRequestProperty("Authorization", "EG1-HMAC-SHA256 client_token=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;access_token=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;timestamp=20160714T19:25:00+0000;nonce=8b97e62f-e5d6-4a57-8f64-db423f24b7ee;signature=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
      BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));     
      String line;
      while ((line = rd.readLine()) != null) {
       result.append(line);
      }
      rd.close();
      return result.toString();
   }

   public static void main(String[] args) throws Exception
   {
     System.out.println(getHTML("https://akab-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.luna.akamaiapis.net/alerts/v1/portal-user?status=active"));
   }
}

I take back one:

Exception in thread "main" java.io.IOException: Server returned HTTP response code: 401 for URL: https://xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.luna.akamaiapis.net/papi/v0/contracts
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at com.akamai.edgegrid.auth.C.getHTML(C.java:17)
at com.akamai.edgegrid.auth.C.main(C.java:28)

But I wanted to see the header back ex:

{
  "type": "https://problems./-/pep-authn/request-error",
  "title": "Bad request",
  "status": 401,
  "detail": "Error message is here",
  "instance": "https://xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.luna.akamaiapis.net/papi/v0/contracts",
  "method": "GET",
  "serverIp": "23.45.226.189",
  "clientIp": "200.220.180.109",
  "requestId": "34799682",
  "requestTime": "2016-07-14T19:32:10Z"
}

I just got the http fault code... I haven’t touched java in years....

Answer 1

If I understand correctly you’re wanting to see the headers of your request response.

For this use methods HttpURLConnection.getHeader...(), as an example getHeaderFields(), which returns the key map and header values, or getHeaderFieldKey(String name), that returns the key value name.

To iterate through the map:

Map<String, List<String>> responseMap = connection.getHeaderFields();
for (String chave : responseMap.keySet()) {
    System.out.println(chave + " = ");

    List<String> valores = responseMap.get(chave);
    for (int i = 0; i < valores.size(); i++) {
        String valor = valores.get(i);
        System.out.println(valor + ", ");
    }
}