001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.web;
018
019import java.io.IOException;
020import java.io.PrintWriter;
021import java.util.Hashtable;
022import java.util.Map;
023
024import javax.jms.Destination;
025import javax.jms.JMSException;
026import javax.jms.Message;
027import javax.jms.Session;
028import javax.servlet.ServletException;
029import javax.servlet.http.HttpServletRequest;
030import javax.servlet.http.HttpServletResponse;
031
032/**
033 * A servlet which will publish dummy market data prices
034 * 
035 * 
036 */
037public class PortfolioPublishServlet extends MessageServletSupport {
038
039    private static final int MAX_DELTA_PERCENT = 1;
040    private static final Map<String, Double> LAST_PRICES = new Hashtable<String, Double>();
041
042    public void init() throws ServletException {
043        super.init();
044    }
045
046    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
047        PrintWriter out = response.getWriter();
048        String[] stocks = request.getParameterValues("stocks");
049        if (stocks == null || stocks.length == 0) {
050            out.println("<html><body>No <b>stocks</b> query parameter specified. Cannot publish market data</body></html>");
051        } else {
052            Integer total = (Integer)request.getSession(true).getAttribute("total");
053            if (total == null) {
054                total = Integer.valueOf(0);
055            }
056
057            int count = getNumberOfMessages(request);
058            total = Integer.valueOf(total.intValue() + count);
059            request.getSession().setAttribute("total", total);
060
061            try {
062                WebClient client = WebClient.getWebClient(request);
063                for (int i = 0; i < count; i++) {
064                    sendMessage(client, stocks);
065                }
066                out.print("<html><head><meta http-equiv='refresh' content='");
067                String refreshRate = request.getParameter("refresh");
068                if (refreshRate == null || refreshRate.length() == 0) {
069                    refreshRate = "1";
070                }
071                out.print(escape(refreshRate));
072                out.println("'/></head>");
073                out.println("<body>Published <b>" + escape(Integer.toString(count)) + "</b> of " + escape(Integer.toString(total))
074                        + " price messages.  Refresh = " + escape(refreshRate) + "s");
075                out.println("</body></html>");
076
077            } catch (JMSException e) {
078                out.println("<html><body>Failed sending price messages due to <b>" + e + "</b></body></html>");
079                log("Failed to send message: " + e, e);
080            }
081        }
082    }
083
084    protected void sendMessage(WebClient client, String[] stocks) throws JMSException {
085        Session session = client.getSession();
086
087        int idx = 0;
088        while (true) {
089            idx = (int)Math.round(stocks.length * Math.random());
090            if (idx < stocks.length) {
091                break;
092            }
093        }
094        String stock = stocks[idx];
095        Destination destination = session.createTopic("STOCKS." + stock);
096        String stockText = createStockText(stock);
097        log("Sending: " + stockText + " on destination: " + destination);
098        Message message = session.createTextMessage(stockText);
099        client.send(destination, message);
100    }
101
102    protected String createStockText(String stock) {
103        Double value = LAST_PRICES.get(stock);
104        if (value == null) {
105            value = new Double(Math.random() * 100);
106        }
107
108        // lets mutate the value by some percentage
109        double oldPrice = value.doubleValue();
110        value = new Double(mutatePrice(oldPrice));
111        LAST_PRICES.put(stock, value);
112        double price = value.doubleValue();
113
114        double offer = price * 1.001;
115
116        String movement = (price > oldPrice) ? "up" : "down";
117        return "<price stock='" + stock + "' bid='" + price + "' offer='" + offer + "' movement='" + movement + "'/>";
118    }
119
120    protected double mutatePrice(double price) {
121        double percentChange = (2 * Math.random() * MAX_DELTA_PERCENT) - MAX_DELTA_PERCENT;
122
123        return price * (100 + percentChange) / 100;
124    }
125
126    protected int getNumberOfMessages(HttpServletRequest request) {
127        String name = request.getParameter("count");
128        if (name != null) {
129            return Integer.parseInt(name);
130        }
131        return 1;
132    }
133
134    protected String escape(String text) throws IOException {
135        return java.net.URLEncoder.encode(text, "UTF-8");
136    }
137}