Urlbox.java

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Map;
import java.util.HashMap;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

public class Urlbox { 

  private String key;
  private String secret;

  Urlbox(String api_key, String api_secret) {
    this.key = api_key;
    this.secret = api_secret;
  }

  // main method demos Example Usage
  public static void main(String[] args) { 
    String urlboxKey = "your-urlbox-api-key";
    String urlboxSecret = "your-urlbox-secret";

    // Set request options
    Map<String, Object> options = new HashMap<String, Object>();
    options.put("width", 1280);
    options.put("height", 1024);
    options.put("thumb_width", 240);
    options.put("full_page", "false");
    options.put("force", "false");

    // Create urlbox object with api key and secret
    Urlbox urlbox = new Urlbox(urlboxKey, urlboxSecret);
    try {
      // Call generateUrl function of urlbox object
      String urlboxUrl = urlbox.generateUrl("bbc.co.uk", options);
      // Now do something with urlboxUrl.. put in img tag, etc..
    } catch (UnsupportedEncodingException ex) {
      throw new RuntimeException("Problem with url encoding", ex);
    }
  }

  public String generateUrl(String url, Map<String,Object> options) throws UnsupportedEncodingException {

    String encodedUrl = URLEncoder.encode(url, "UTF-8");
    String queryString = String.format("url=%s", encodedUrl);

    for (Map.Entry<String, Object> entry : options.entrySet()) {
      String queryParam = "&"+entry.getKey()+"="+entry.getValue(); 
      queryString += queryParam;
    }

    String token = generateToken(queryString, this.secret);
    String result = String.format("https://api.urlbox.io/v1/%s/%s/png?%s", this.key, token, queryString);
    System.out.println(result);
    return result;
  }
     
  private String generateToken(String input, String key) {
    String lSignature = "None";
    try {
      Mac lMac = Mac.getInstance("HmacSHA1");
      SecretKeySpec lSecret = new SecretKeySpec(key.getBytes(), "HmacSHA1");
      lMac.init(lSecret);

      byte[] lDigest = lMac.doFinal(input.getBytes());
      BigInteger lHash = new BigInteger(1, lDigest);
      lSignature = lHash.toString(16);
      if ((lSignature.length() % 2) != 0) {
        lSignature = "0" + lSignature;
      }
    } catch (NoSuchAlgorithmException lEx) {
      throw new RuntimeException("Problems calculating HMAC", lEx);
    } catch (InvalidKeyException lEx) {
      throw new RuntimeException("Problems calculating HMAC", lEx);
    }
    return lSignature;
  }
}