|
1
18 package org.apache.activemq.web;
19
20 import javax.jms.Destination  ;
21 import javax.jms.JMSException ;
22 import javax.jms.Message ;
23 import javax.jms.Session ;
24 import javax.servlet.ServletException ;
25 import javax.servlet.http.HttpServletRequest ;
26 import javax.servlet.http.HttpServletResponse ;
27 import java.io.IOException ;
28 import java.io.PrintWriter ;
29 import java.util.Hashtable ;
30 import java.util.Map ;
31
32
37 public class PortfolioPublishServlet extends MessageServletSupport {
38
39 private static final int maxDeltaPercent = 1;
40 private static final Map lastPrices = new Hashtable ();
41 private boolean ricoStyle = true;
42
43
44 public void init() throws ServletException {
45 super.init();
46
47 ricoStyle = asBoolean(getServletConfig().getInitParameter("rico"), true);
48 }
49
50 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException , IOException {
51 PrintWriter out = response.getWriter();
52 String [] stocks = request.getParameterValues("stocks");
53 if (stocks == null || stocks.length == 0) {
54 out.println("<html><body>No <b>stocks</b> query parameter specified. Cannot publish market data</body></html>");
55 }
56 else {
57 Integer total=(Integer )request.getSession(true).getAttribute("total");
58 if (total==null)
59 total=new Integer (0);
60
61
62 int count = getNumberOfMessages(request);
63 total=new Integer (total.intValue()+count);
64 request.getSession().setAttribute("total",total);
65
66 try {
67 WebClient client = WebClient.getWebClient(request);
68 for (int i = 0; i < count; i++) {
69 sendMessage(client, stocks);
70 }
71 out.print("<html><head><meta http-equiv='refresh' content='");
72 String refreshRate = request.getParameter("refresh");
73 if (refreshRate == null || refreshRate.length() == 0) {
74 refreshRate = "1";
75 }
76 out.print(refreshRate);
77 out.println("'/></head>");
78 out.println("<body>Published <b>" + count + "</b> of "+total+ " price messages. Refresh = "+refreshRate+"s");
79 out.println("</body></html>");
80
81 }
82 catch (JMSException e) {
83 out.println("<html><body>Failed sending price messages due to <b>" + e + "</b></body></html>");
84 log("Failed to send message: " + e, e);
85 }
86 }
87 }
88
89 protected void sendMessage(WebClient client, String [] stocks) throws JMSException {
90 Session session = client.getSession();
91
92 int idx = 0;
93 while (true) {
94 idx = (int) Math.round(stocks.length * Math.random());
95 if (idx < stocks.length) {
96 break;
97 }
98 }
99 String stock = stocks[idx];
100 Destination destination = session.createTopic("STOCKS." + stock);
101 String stockText = createStockText(stock);
102 log("Sending: " + stockText + " on destination: " + destination);
103 Message message = session.createTextMessage(stockText);
104 client.send(destination, message);
105 }
106
107 protected String createStockText(String stock) {
108 Double value = (Double ) lastPrices.get(stock);
109 if (value == null) {
110 value = new Double (Math.random() * 100);
111 }
112
113 double oldPrice = value.doubleValue();
115 value = new Double (mutatePrice(oldPrice));
116 lastPrices.put(stock, value);
117 double price = value.doubleValue();
118
119 double offer = price * 1.001;
120
121 String movement = (price > oldPrice) ? "up" : "down";
122 return "<price stock='" + stock + "' bid='" + price + "' offer='" + offer + "' movement='" + movement + "'/>";
123 }
124
125 protected double mutatePrice(double price) {
126 double percentChange = (2 * Math.random() * maxDeltaPercent) - maxDeltaPercent;
127
128 return price * (100 + percentChange) / 100;
129 }
130
131 protected int getNumberOfMessages(HttpServletRequest request) {
132 String name = request.getParameter("count");
133 if (name != null) {
134 return Integer.parseInt(name);
135 }
136 return 1;
137 }
138 }
139 |
Popular Tags |
Java API By Example, From Geeks To Geeks.