This code gets a Gfycat link from a .gif URL and authenticates if neccessary. This is currently failing with a 400 BadRequest before it even reaches the https://api.gfycat.com/v1/gfycats call Raw

HttpUtil.java

package me.ccrama.redditslide.util;

import android.content.Context;
import android.support.annotation.Nullable;
import android.text.TextUtils;

import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonSyntaxException;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import me.ccrama.redditslide.Constants;
import me.ccrama.redditslide.SecretConstants;
import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okhttp3.ResponseBody;
import okio.Buffer;

/**
 * A class that helps with HTTP requests and response parsing.
 *
 * Class created by Fernando Barillas on 7/13/16.
 * Class edited from Slide for Reddit https://github.com/ccrama/Slide/blob/98f5df0eb945fac7d5b8d2e7102cfacfaa754b4c/app/src/main/java/me/ccrama/redditslide/util/HttpUtil.java
 */
public class HttpUtil {

    private static String gfycatToken = "";
    private static long expires;

    public static JsonObject transcodeGfycatGetJsonObject(final Context context, final OkHttpClient client, final Gson gson,
            final String urlToConvert) {

        //Check for a valid Gfycat authentication, dirty implementation at the moment because it doesn't refresh, but this code is still not working
        if(System.currentTimeMillis() > expires || gfycatToken.isEmpty()){
            Map<String, String> headers = new HashMap<>();
            headers.put("grant_type", "client_credentials");
            headers.put("client_id", "2_fEI_VM");
            headers.put("content_type", "application/json");
            headers.put("client_secret", SecretConstants.getGfycatAPIKey(context)); //Gets private key from a local file on my computer, compiles with the key but it doesn't get pushed to GitHub
            JsonObject o = getPostJsonObject(client, gson, "https://api.gfycat.com/v1/oauth/token", headers);
          
            /* Logging shows these are the request params:
              Request{method=POST, url=https://api.gfycat.com/v1/oauth/token, tag=null}
              content_type: application/json
              grant_type: client_credentials
              client_secret: secret
              client_id: 2_fEI_VM*/

            if(o.has("expires_in")){ //Hopefully a valid token
                expires = System.currentTimeMillis()  + o.get("expires_in").getAsLong();
                gfycatToken = o.get("access_token").getAsString();
            }
        }
        
        //Get the converted gfycat
        Map<String, String> imgurHeadersMap = new HashMap<>();
        imgurHeadersMap.put("fetchUrl", urlToConvert);
        imgurHeadersMap.put("Authorization", gfycatToken);
        return getJsonObject(client, gson, "https://api.gfycat.com/v1/gfycats", imgurHeadersMap);
    }


    //Gets a JSON object with a POST request
    public static JsonObject getPostJsonObject(final OkHttpClient client, final Gson gson,
            final String apiUrl, @Nullable final Map<String, String> headersMap) {
        if (client == null || gson == null || TextUtils.isEmpty(apiUrl)) return null;
        MediaType MIMEType= MediaType.parse("application/json; charset=utf-8");
        RequestBody requestBody = RequestBody.create (MIMEType,"{}");
        Request.Builder requestB = new Request.Builder().url(apiUrl);
        if (headersMap != null && headersMap.size() > 0) {
            // Add headers to the request if headers are available
            for (Map.Entry<String, String> entry : headersMap.entrySet()) {
                requestB.addHeader(entry.getKey(), entry.getValue());
            }
        }


        Request request= requestB.post(requestBody).build();
        try {
            Response response = client.newCall(request).execute();
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response); //Crashes here with a 400 BadRequest
            ResponseBody responseBody = response.body();
            String json = responseBody.string();
            responseBody.close();
            return gson.fromJson(json, JsonObject.class);
        } catch (JsonSyntaxException | IOException e) {
            LogUtil.e(e, "Error " + apiUrl);
        }
        return null;
    }
    
    /**
     * Gets a JsonObject by calling apiUrl and parsing the JSON response String. This method accepts
     * a Map that can contain custom headers to include in the request.
     *
     * @param client     The OkHTTP client to use to make the request
     * @param gson       The GSON instance to use to parse the response String
     * @param apiUrl     The URL to call to get the response from
     * @param headersMap The headers to include in the request. Can be null to not add any headers
     * @return A JsonObject representation of the API response, null when there was an error or
     * Exception thrown by the HTTP call
     */
    public static JsonObject getJsonObject(final OkHttpClient client, final Gson gson,
            final String apiUrl, @Nullable final Map<String, String> headersMap) {
        if (client == null || gson == null || TextUtils.isEmpty(apiUrl)) return null;
        Request.Builder builder = new Request.Builder().url(apiUrl);

        if (headersMap != null && headersMap.size() > 0) {
            // Add headers to the request if headers are available
            for (Map.Entry<String, String> entry : headersMap.entrySet()) {
                builder.addHeader(entry.getKey(), entry.getValue());
            }
        }

        Request request = builder.build();
        try {
            Response response = client.newCall(request).execute();
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
            ResponseBody responseBody = response.body();
            String json = responseBody.string();
            responseBody.close();
            return gson.fromJson(json, JsonObject.class);
        } catch (JsonSyntaxException | IOException e) {
            LogUtil.e(e, "Error " + apiUrl);
        }
        return null;
    }

}