CoinTracking API - Java Example

CointrackingAPI.java

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SignatureException;
import java.util.Date;
import java.util.Formatter;

public class CointrackingAPI {

    private static final String endpoint = "https://cointracking.info/api/v1/";
    private static final String HMAC_SHA512 = "HmacSHA512";
    private String client;
    private String secret;


    public CointrackingAPI(String client, String secret)
    {
        this.client = client;
        this.secret = secret;
    }


    private static String calculateHMAC(String data, String key)
            throws SignatureException, NoSuchAlgorithmException, InvalidKeyException
    {
        SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), HMAC_SHA512);
        Mac mac = Mac.getInstance(HMAC_SHA512);
        mac.init(secretKeySpec);
        return toHexString(mac.doFinal(data.getBytes()));
    }

    private static String toHexString(byte[] bytes) {
        Formatter formatter = new Formatter();
        for (byte b : bytes) {
            formatter.format("%02x", b);
        }
        return formatter.toString();
    }




    public String executePost(String method, CointrackingAPIParams params) {
        HttpURLConnection connection = null;

        try {


            params.addParam("method", method);
            params.addParam("nonce", String.valueOf(new Date().getTime()));
            String postParameters = params.getQuery();

            String signature = calculateHMAC(postParameters, secret);


            //Create connection
            URL url = new URL(endpoint);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setRequestProperty("Content-Length", Integer.toString(postParameters.getBytes().length));
            connection.setRequestProperty("Key", client);
            connection.setRequestProperty("Sign", signature.replaceAll("\n", ""));

            connection.setUseCaches(false);
            connection.setDoOutput(true);

            //Send request
            DataOutputStream wr = new DataOutputStream (connection.getOutputStream());
            wr.writeBytes(postParameters);
            wr.close();

            //Get Response
            InputStream is = connection.getInputStream();
            BufferedReader rd = new BufferedReader(new InputStreamReader(is));
            StringBuilder response = new StringBuilder(); // or StringBuffer if Java version 5+
            String line;
            while ((line = rd.readLine()) != null) {
                response.append(line);
                response.append('\r');
            }
            rd.close();
            return response.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }

}

CointrackingAPIParams.java

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.List;

public class CointrackingAPIParams {
    private List<AbstractMap.SimpleEntry<String, String>> entries = new ArrayList<>();

    public CointrackingAPIParams withParam(String key, String value)
    {
        addParam(key, value);
        return this;
    }

    public void addParam(String key, String value)
    {
        entries.add(new AbstractMap.SimpleEntry<>(key, value));
    }

    public String getQuery() throws UnsupportedEncodingException
    {
        StringBuilder result = new StringBuilder();
        boolean first = true;

        for (AbstractMap.SimpleEntry<String, String> pair : entries)
        {
            if (first)
                first = false;
            else
                result.append("&");

            result.append(URLEncoder.encode(pair.getKey(), "UTF-8"));
            result.append("=");
            result.append(URLEncoder.encode(pair.getValue(), "UTF-8"));
        }

        return result.toString();
    }
}