(Android™) Refresh eBay Application Access Token

This example shows how to get a new eBay REST API access token when the original is close to expiration.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // If a new access token must be fetched, this example will save the JSON
    // containing the token to a file.  The contents of the JSON will look
    // like this:

    // 	{ 
    // 	  "access_token": "v^1.1#i^1#p^1#I^3#r^0# ... Ajp1BQhJDgAA",
    // 	  "token_type": "Application Access Token",
    // 	  "expires_in": 7200,
    // 	  "refresh_token": "N/A",
    // 	  "expire_time": "2017-04-16T14:44:20Z"
    // 	}

    boolean success;
    CkJsonObject json = new CkJsonObject();
    json.put_EmitCompact(false);
    CkDateTime dtExpire = new CkDateTime();

    // First, we'll see if this file already exists from previously
    // running this code.
    String tokenFilePath = "qa_data/tokens/ebay.json";
    CkFileAccess fac = new CkFileAccess();
    if (fac.FileExists(tokenFilePath) == true) {
        json.LoadFile(tokenFilePath);

        // Get the current date/time, then get the expire date/time from the JSON.
        CkDateTime dtNow = new CkDateTime();
        dtNow.SetFromCurrentSystemTime();
        // Add 30 seconds to dtNow so that we refresh if within 30 seconds of the expiration.
        dtNow.AddSeconds(30);

        dtExpire.SetFromTimestamp(json.stringOf("expire_time"));

        if (dtNow.GetAsUnixTime(false) < dtExpire.GetAsUnixTime(false)) {
            // The token has not yet expired.  We can use the access token from this JSOn.
            Log.i(TAG, "Non-expired access token: " + json.stringOf("access_token"));
            return;
            }

        }

    // If we fall through to here, then either the existing access token expired,
    // or we haven't yet fetched an access token for the first time.
    // The remainder of this code snippet fetches the access token and saves
    // it to the file.

    CkHttp http = new CkHttp();

    // If using the sandbox, the target endpoint will be:
    // POST https://api.sandbox.ebay.com/identity/v1/oauth2/token

    // If using the production (live) system, the target endpoint will be:
    // POST https://api.ebay.com/identity/v1/oauth2/token

    // The eBay client_id and client_secret needs to be sent
    // in a Basic Authorization  request header, which has this format:
    // Authorization: Basic <B64_encoded_oauth_credentials>

    // Chilkat takes care of it.  You only need to set the Login = client_id,
    // and password = client_secret, and indicate you want "Basic" HTTP Authorization.
    http.put_Login("EBAY_CLIENT_ID");
    http.put_Password("EBAY_CLIENT_SECRET");
    http.put_BasicAuth(true);

    // Let's do the following POST:

    //   HTTP method:   POST
    //   URL (Sandbox): https://api.sandbox.ebay.com/identity/v1/oauth2/token
    // 
    //   HTTP headers:
    //     Content-Type = application/x-www-form-urlencoded
    //     Authorization = Basic <B64-encoded-oauth-credentials>
    // 
    //   Request body (wrapped for readability):
    //     grant_type=client_credentials&
    //     redirect_uri=<RuName-value>&
    //     scope=https://api.ebay.com/oauth/api_scope
    // 

    // Create an HttpRequest object to hold the request params.
    CkHttpRequest req = new CkHttpRequest();
    req.put_HttpVerb("POST");
    req.AddParam("grant_type","client_credentials");
    // (The RuName value that eBay assigns to your application.)
    req.AddParam("redirect_uri","EBAY_RUNAME_VALUE");
    req.AddParam("scope","https://api.ebay.com/oauth/api_scope");

    // (The PostUrlEncoded method automatically sets the Content-Type header equal to "application/x-www-form-urlencoded")
    String endPoint = "https://api.sandbox.ebay.com/identity/v1/oauth2/token";
    CkHttpResponse resp = http.PostUrlEncoded(endPoint,req);
    if (http.get_LastMethodSuccess() != true) {
        Log.i(TAG, http.lastErrorText());
        return;
        }

    // The response is JSON..
    json.Load(resp.bodyStr());

    // If the response status code is not 200, then it failed.
    Log.i(TAG, "Response status code = " + String.valueOf(resp.get_StatusCode()));
    if (resp.get_StatusCode() != 200) {
        Log.i(TAG, json.emit());
        Log.i(TAG, "Failed.");
        return;
        }

    // This application token is only valid for 7200 seconds (2 hours).  We'll want to refresh
    // it before it expires.  (There is an online example for that..)
    // For now, let's save the JSON to a file for our application to use.

    // But before doing that, let's add to the JSON an expiration timestamp
    // so we know when to refresh the token.
    dtExpire.SetFromCurrentSystemTime();
    dtExpire.AddSeconds(json.IntOf("expires_in"));
    json.AppendString("expire_time",dtExpire.getAsTimestamp(false));

    // Persist the JSON to a file.
    success = fac.WriteEntireTextFile(tokenFilePath,json.emit(),"utf-8",false);
    if (success != true) {
        Log.i(TAG, fac.lastErrorText());
        Log.i(TAG, "Failed to save eBay Application token to file.");
        return;
        }

    // We successfully retrieved a new eBay access token.
    String accessToken = json.stringOf("access_token");

    Log.i(TAG, "Use this new access token: " + accessToken);

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}