Java tutorial
/* * Copyright (C) 2014 desrever <desrever at nubits.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ package com.nubits.nubot.pricefeeds; /** * * @author desrever <desrever at nubits.com> */ import com.nubits.nubot.global.Passwords; import com.nubits.nubot.models.Amount; import com.nubits.nubot.models.CurrencyPair; import com.nubits.nubot.models.LastPrice; import com.nubits.nubot.utils.Utils; import java.io.IOException; import java.util.logging.Logger; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.json.simple.parser.JSONParser; public class ExchangeratelabPriceFeed extends AbstractPriceFeed { private static final Logger LOG = Logger.getLogger(ExchangeratelabPriceFeed.class.getName()); public ExchangeratelabPriceFeed() { name = "exchangeratelab"; refreshMinTime = 8 * 60 * 60 * 1000; //8 hours } @Override public LastPrice getLastPrice(CurrencyPair pair) { long now = System.currentTimeMillis(); long diff = now - lastRequest; if (diff >= refreshMinTime) { String url = getUrl(pair); String htmlString; try { htmlString = Utils.getHTML(url, true); } catch (IOException ex) { LOG.severe(ex.toString()); return new LastPrice(true, name, pair.getOrderCurrency(), null); } JSONParser parser = new JSONParser(); try { JSONObject httpAnswerJson = (JSONObject) (parser.parse(htmlString)); JSONArray array = (JSONArray) httpAnswerJson.get("rates"); String lookingfor = pair.getOrderCurrency().getCode().toUpperCase(); boolean found = false; double rate = -1; for (int i = 0; i < array.size(); i++) { JSONObject temp = (JSONObject) array.get(i); String tempCurrency = (String) temp.get("to"); if (tempCurrency.equalsIgnoreCase(lookingfor)) { found = true; rate = Utils.getDouble((Double) temp.get("rate")); rate = Utils.round(1 / rate, 8); } } lastRequest = System.currentTimeMillis(); if (found) { lastPrice = new LastPrice(false, name, pair.getOrderCurrency(), new Amount(rate, pair.getPaymentCurrency())); return lastPrice; } else { LOG.warning("Cannot find currency " + lookingfor + " on feed " + name); return new LastPrice(true, name, pair.getOrderCurrency(), null); } } catch (Exception ex) { LOG.severe(ex.toString()); lastRequest = System.currentTimeMillis(); return new LastPrice(true, name, pair.getOrderCurrency(), null); } } else { LOG.fine("Wait " + (refreshMinTime - (System.currentTimeMillis() - lastRequest)) + " ms " + "before making a new request. Now returning the last saved price\n\n"); return lastPrice; } } private String getUrl(CurrencyPair pair) { return "http://api.exchangeratelab.com/api/current?apikey=" + Passwords.EXCHANGE_RATE_LAB; } }