Quote from: flash10101 on August 23, 2016, 01:46:00 PM

I also tried to connect to the Poloniex API with Java. I followed some advice from this thread and came up with the following code, but for some reason, I always get the error: Invalid command

Any idea what I am doing wrong? Huh

Code:

public static String POLONIEX_SECRET_KEY = "my secret"; //KEY
public static String POLONIEX_API_KEY = "my key"; // TODO API KEY

public static void main(String[] args) {

try {
accessPoloniex();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
public static final long generateNonce(){

Date d = new Date();
return d.getTime();
}

public static final void accessPoloniex() throws IOException{

String nonce = new BigDecimal(Polo2.generateNonce()).toString();

String connectionString = "https://poloniex.com/tradingApi";

String queryArgs = "command=returnBalances";

String hmac512 = hmac512Digest(queryArgs, POLONIEX_SECRET_KEY);

// Produce the output
ByteArrayOutputStream out = new ByteArrayOutputStream();
Writer writer = new OutputStreamWriter(out, "UTF-8");
writer.append(queryArgs);

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost post = new HttpPost(connectionString);

post.setHeader("Key", POLONIEX_API_KEY);
post.setHeader("Sign", hmac512);

post.setEntity(new ByteArrayEntity(out.toByteArray()));
List params = new ArrayList<>();
params.add(new BasicNameValuePair("nonce", nonce));

CloseableHttpResponse response = null;
Scanner in = null;
try
{
post.setEntity(new UrlEncodedFormEntity(params));
response = httpClient.execute(post);
// System.out.println(response.getStatusLine());
HttpEntity entity = response.getEntity();
in = new Scanner(entity.getContent());
while (in.hasNext())
{
System.out.println(in.next());

}
EntityUtils.consume(entity);
} finally
{
in.close();
response.close();
}

}

public static String hmac512Digest(String msg, String keyString) {

Mac shaMac;
try {
shaMac = Mac.getInstance("HmacSHA512");
SecretKeySpec keySpec = new SecretKeySpec(keyString.getBytes(), "HmacSHA512");

shaMac.init(keySpec);
final byte[] macData = shaMac.doFinal(msg.getBytes());
return Hex.encodeHexString(macData); //again with try/catch for InvalidKeyException

} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return null;
}

I haven't tried your code but two things that work in my code:

- nonce is part of the query string
- I use System.currentTimeMillis() to create the nonce. Not sure if your way will work or not but I know mine does and its much simpler.