traininfoservice/banedk/DepartureServlet.java

package dk.thoerup.traininfoservice.banedk;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import javax.xml.transform.Source;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;

import dk.thoerup.android.traininfo.common.DepartureBean;
import dk.thoerup.circuitbreaker.CircuitBreakerException;
import dk.thoerup.traininfoservice.StationDAO;
import dk.thoerup.traininfoservice.Statistics;

/**
 * Servlet implementation class DepartureServlet
 */
@WebServlet(urlPatterns={"/DepartureServlet"})
public class DepartureServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;
        
        Logger logger = Logger.getLogger( DepartureServlet.class.getName() );

        DepartureFetcher fetcher;


        TransformerFactory xslTransFact;
        Templates xslTemplate;
        

        @Override
        public void init() throws ServletException {
                super.init();

                boolean useAzureSite =  Boolean.parseBoolean( getServletContext().getInitParameter("useazuresite") );
                int cacheTimeout =  Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
                int replyTimeout =  Integer.parseInt( getServletContext().getInitParameter("reply_timeout") ); 
                logger.info( "DepartureServlet, use azure site=" + useAzureSite + ", cache=" + cacheTimeout);
                fetcher = new DepartureFetcher(useAzureSite, cacheTimeout, replyTimeout);
                
                xslTransFact = TransformerFactory.newInstance();
                
                String xslPath = getServletContext().getRealPath("/departures.xsl");
                Source stylesheet = new StreamSource( new File(xslPath) );
                
                try {
                        xslTemplate = xslTransFact.newTemplates(stylesheet);
                } catch (Exception e) {
                        throw new ServletException(e);
                }
        }

        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {           
                if (req.getParameter("station") == null) {
                        resp.sendError(400, "not enough parameters (station)");
                        return;
                }
                if (req.getParameter("format") == null) {
                        resp.sendError(400, "not enough parameters (format)");
                        return;                 
                }
                
                boolean arrival = false;
                try {
                        arrival = Integer.parseInt( req.getParameter("arrival")) != 0;
                } catch (Exception e) {}
                
                Statistics.getInstance().incrementDepartureLookups();
                
                int station = Integer.parseInt( req.getParameter("station") );
                String format = req.getParameter("format");

                DepartureBean beans;            

                try {
                        beans = fetcher.cachedLookupDepartures(station, arrival);
                        beans.arrival = arrival;
                } catch (java.io.IOException ioe) {
                        logger.warning("Read failed, station="+station + ". " + ioe.getMessage() );
                        Statistics.getInstance().incrementDepartureErrors();
                        resp.sendError(500);
                        return;
                } catch (CircuitBreakerException cbe) {
                        logger.warning("Circuitbreaker - failing fast, station=" +station);
                        Statistics.getInstance().incrementDepartureErrors();
                        resp.sendError(500);
                        return;
                } catch (StationDAO.NostationException nse) {
                        logger.log(Level.WARNING, "Station not in Database, station=" +station);
                        Statistics.getInstance().incrementDepartureErrors();
                        resp.sendError(400, "invalid station ID");
                        return;                 
                } catch (Exception e) {                 
                        logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
                        Statistics.getInstance().incrementDepartureErrors();
                        resp.sendError(500);
                        return;
                }
                
                resp.setDateHeader("Expires", 0);
                resp.setHeader("Cache-Control", "no-cache, must-revalidate");
                
                if (format.equalsIgnoreCase("xml")) {
                        resp.setContentType("text/xml");
                        resp.getWriter().print( formatXml(beans) );
                } else if (format.equalsIgnoreCase("html")) {
                        /*
                        String advStr = req.getParameter("advanced");
                        boolean advanced = advStr != null ? Boolean.parseBoolean(advStr) : false;
                        
                        req.setAttribute("advanced", advanced);
                        req.setAttribute("departurebeans", beans);
                        req.setAttribute("stationID", station );
                        getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);*/
                        resp.setContentType("text/html");
                        resp.getWriter().print(  xmlToHtml(formatXml(beans))  );
                } else {
                        resp.sendError(400, "Unknown format");                  
                }

        }

        protected String formatXml(DepartureBean beans) throws ServletException{
                
                Serializer serializer = new Persister();

                StringWriter out = new StringWriter();

                try {
                        serializer.write(beans, out);
                } catch (Exception e) {
                        throw new ServletException(e);
                }
                
                return out.toString();
        }
        
        protected String xmlToHtml(String input) throws ServletException {

                try {                                   
                        Transformer trans = xslTemplate.newTransformer();                       
                
                        Source xml = new StreamSource( new ByteArrayInputStream(input.getBytes() ));
                        StringWriter out = new StringWriter();
                        trans.transform(xml, new StreamResult(out));            
                
                        return out.toString();
                } catch (Exception e) {
                        throw new ServletException(e);
                }
        }

}
1	torben	307	package dk.thoerup.traininfoservice.banedk;
2
3	torben	1075	import java.io.ByteArrayInputStream;
4			import java.io.File;
5	torben	307	import java.io.IOException;
6	torben	1190	import java.io.StringWriter;
7	torben	348	import java.util.logging.Level;
8			import java.util.logging.Logger;
9	torben	307
10			import javax.servlet.ServletException;
11	torben	958	import javax.servlet.annotation.WebServlet;
12	torben	307	import javax.servlet.http.HttpServlet;
13			import javax.servlet.http.HttpServletRequest;
14			import javax.servlet.http.HttpServletResponse;
15	torben	1075
16			import javax.xml.transform.Source;
17	torben	1091	import javax.xml.transform.Templates;
18	torben	1075	import javax.xml.transform.Transformer;
19	torben	307	import javax.xml.transform.TransformerFactory;
20	torben	1075	import javax.xml.transform.stream.StreamResult;
21			import javax.xml.transform.stream.StreamSource;
22	torben	307
23	torben	1060	import org.simpleframework.xml.Serializer;
24			import org.simpleframework.xml.core.Persister;
25	torben	307
26	torben	1061	import dk.thoerup.android.traininfo.common.DepartureBean;
27	torben	468	import dk.thoerup.circuitbreaker.CircuitBreakerException;
28	torben	1145	import dk.thoerup.traininfoservice.StationDAO;
29	torben	711	import dk.thoerup.traininfoservice.Statistics;
30	torben	307
31			/**
32			* Servlet implementation class DepartureServlet
33			*/
34	torben	958	@WebServlet(urlPatterns={"/DepartureServlet"})
35	torben	307	public class DepartureServlet extends HttpServlet {
36			private static final long serialVersionUID = 1L;
37	torben	348
38			Logger logger = Logger.getLogger( DepartureServlet.class.getName() );
39	torben	307
40	torben	580	DepartureFetcher fetcher;
41	torben	1075
42
43	torben	307
44	torben	1091	TransformerFactory xslTransFact;
45			Templates xslTemplate;
46	torben	1075
47	torben	307
48	torben	425	@Override
49	torben	580	public void init() throws ServletException {
50			super.init();
51	torben	584
52	torben	1034	boolean useAzureSite = Boolean.parseBoolean( getServletContext().getInitParameter("useazuresite") );
53	torben	584	int cacheTimeout = Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
54	torben	1026	int replyTimeout = Integer.parseInt( getServletContext().getInitParameter("reply_timeout") );
55	torben	1036	logger.info( "DepartureServlet, use azure site=" + useAzureSite + ", cache=" + cacheTimeout);
56	torben	1034	fetcher = new DepartureFetcher(useAzureSite, cacheTimeout, replyTimeout);
57	torben	1075
58	torben	1091	xslTransFact = TransformerFactory.newInstance();
59
60			String xslPath = getServletContext().getRealPath("/departures.xsl");
61			Source stylesheet = new StreamSource( new File(xslPath) );
62
63			try {
64			xslTemplate = xslTransFact.newTemplates(stylesheet);
65			} catch (Exception e) {
66			throw new ServletException(e);
67			}
68	torben	580	}
69
70			@Override
71	torben	711	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
72	torben	458	if (req.getParameter("station") == null) {
73	torben	1168	resp.sendError(400, "not enough parameters (station)");
74	torben	458	return;
75			}
76	torben	1168	if (req.getParameter("format") == null) {
77			resp.sendError(400, "not enough parameters (format)");
78			return;
79			}
80	torben	829
81			boolean arrival = false;
82			try {
83			arrival = Integer.parseInt( req.getParameter("arrival")) != 0;
84			} catch (Exception e) {}
85
86	torben	711	Statistics.getInstance().incrementDepartureLookups();
87	torben	458
88	torben	307	int station = Integer.parseInt( req.getParameter("station") );
89			String format = req.getParameter("format");
90
91	torben	1021	DepartureBean beans;
92	torben	307
93			try {
94	torben	829	beans = fetcher.cachedLookupDepartures(station, arrival);
95	torben	1074	beans.arrival = arrival;
96	torben	462	} catch (java.io.IOException ioe) {
97			logger.warning("Read failed, station="+station + ". " + ioe.getMessage() );
98	torben	716	Statistics.getInstance().incrementDepartureErrors();
99	torben	348	resp.sendError(500);
100			return;
101	torben	421	} catch (CircuitBreakerException cbe) {
102	torben	1158	logger.warning("Circuitbreaker - failing fast, station=" +station);
103	torben	716	Statistics.getInstance().incrementDepartureErrors();
104	torben	421	resp.sendError(500);
105			return;
106	torben	1145	} catch (StationDAO.NostationException nse) {
107			logger.log(Level.WARNING, "Station not in Database, station=" +station);
108			Statistics.getInstance().incrementDepartureErrors();
109			resp.sendError(400, "invalid station ID");
110			return;
111	torben	451	} catch (Exception e) {
112	torben	348	logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
113	torben	716	Statistics.getInstance().incrementDepartureErrors();
114	torben	348	resp.sendError(500);
115			return;
116	torben	307	}
117
118			resp.setDateHeader("Expires", 0);
119			resp.setHeader("Cache-Control", "no-cache, must-revalidate");
120
121			if (format.equalsIgnoreCase("xml")) {
122			resp.setContentType("text/xml");
123	torben	1074	resp.getWriter().print( formatXml(beans) );
124	torben	307	} else if (format.equalsIgnoreCase("html")) {
125	torben	1075	/*
126	torben	585	String advStr = req.getParameter("advanced");
127			boolean advanced = advStr != null ? Boolean.parseBoolean(advStr) : false;
128
129			req.setAttribute("advanced", advanced);
130	torben	307	req.setAttribute("departurebeans", beans);
131			req.setAttribute("stationID", station );
132	torben	1075	getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);*/
133			resp.setContentType("text/html");
134			resp.getWriter().print( xmlToHtml(formatXml(beans)) );
135	torben	307	} else {
136	torben	862	resp.sendError(400, "Unknown format");
137	torben	307	}
138
139			}
140
141	torben	1074	protected String formatXml(DepartureBean beans) throws ServletException{
142	torben	1060
143			Serializer serializer = new Persister();
144	torben	307
145	torben	1190	StringWriter out = new StringWriter();
146	torben	307
147	torben	1060	try {
148			serializer.write(beans, out);
149	torben	307	} catch (Exception e) {
150			throw new ServletException(e);
151			}
152	torben	1060
153			return out.toString();
154	torben	307	}
155	torben	1075
156	torben	1091	protected String xmlToHtml(String input) throws ServletException {
157	torben	307
158	torben	1091	try {
159			Transformer trans = xslTemplate.newTransformer();
160	torben	1075
161			Source xml = new StreamSource( new ByteArrayInputStream(input.getBytes() ));
162	torben	1190	StringWriter out = new StringWriter();
163	torben	1075	trans.transform(xml, new StreamResult(out));
164
165			return out.toString();
166			} catch (Exception e) {
167	torben	1091	throw new ServletException(e);
168	torben	1075	}
169			}
170
171	torben	307	}