traininfoservice/banedk/DepartureServlet.java

package dk.thoerup.traininfoservice.banedk;

import java.io.IOException;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import dk.thoerup.circuitbreaker.CircuitBreakerException;
import dk.thoerup.traininfoservice.StationDAO;
import dk.thoerup.traininfoservice.Statistics;

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

        DepartureFetcher fetcher;
    TransformerFactory transformerFactory = TransformerFactory.newInstance();
        DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
        

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

                boolean useTempSite =  Boolean.parseBoolean( getServletContext().getInitParameter("usetempsite") );
                int cacheTimeout =  Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
                logger.info( "DepartureServlet, use temp site=" + useTempSite + ", cache=" + cacheTimeout);
                fetcher = new DepartureFetcher(useTempSite, cacheTimeout);
        }

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

                List<DepartureBean> beans;

                String stationName = StationDAO.getStationName(station);

                try {
                        beans = fetcher.cachedLookupDepartures(station);
                } 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");
                        Statistics.getInstance().incrementDepartureErrors();
                        resp.sendError(500);
                        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, stationName) );
                } else if (format.equalsIgnoreCase("html")) {
                        
                        String advStr = req.getParameter("advanced");
                        boolean advanced = advStr != null ? Boolean.parseBoolean(advStr) : false;
                        
                        req.setAttribute("advanced", advanced);
                        req.setAttribute("stationname", stationName );
                        req.setAttribute("departurebeans", beans);
                        req.setAttribute("stationID", station );
                        getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);
                } else {
                        throw new ServletException("Unknown format");
                }

        }

        protected String formatXml(List<DepartureBean> beans, String stationName) throws ServletException{
                String xml = "";
                try {
                        DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
                        DOMImplementation impl = builder.getDOMImplementation();

                        
                        Document doc = impl.createDocument(null,null,null);
                Element root = doc.createElement("departureinfo");
                root.setAttribute("station", stationName);
                for (DepartureBean departure : beans) {
                        Element train = doc.createElement("train");
                        
                        Element time = doc.createElement("time");
                        time.setTextContent( departure.getTime() );
                        train.appendChild(time);
                        
                        Element updated = doc.createElement("updated");
                        updated.setTextContent( String.valueOf(departure.getUpdated()) );
                        train.appendChild(updated);
                        
                        Element trainNumber = doc.createElement("trainnumber");
                        trainNumber.setTextContent( departure.getTrainNumber() );
                        train.appendChild(trainNumber);
                        
                        Element destination = doc.createElement("destination");
                        destination.setTextContent( departure.getDestination());
                        train.appendChild(destination);
                        
                        Element origin = doc.createElement("origin");
                        origin.setTextContent( departure.getOrigin() );
                        train.appendChild(origin);
                        
                        Element location= doc.createElement("location");
                        location.setTextContent( departure.getLocation() );
                        train.appendChild(location);
                        
                        Element status = doc.createElement("status");
                        status.setTextContent( departure.getStatus() );
                        train.appendChild(status);
                        
                        Element note = doc.createElement("note");
                        note.setTextContent( departure.getNote() );
                        train.appendChild(note);
                        
                        Element type = doc.createElement("type");
                        type.setTextContent( departure.getType() );
                        train.appendChild(type);
                        
                        root.appendChild(train);
                }
                
                doc.appendChild(root);
                
                
                DOMSource domSource = new DOMSource(doc);

                Transformer transformer = transformerFactory.newTransformer();
                //transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
                transformer.setOutputProperty(OutputKeys.METHOD, "xml");
                transformer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
                transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
                transformer.setOutputProperty(OutputKeys.INDENT, "yes");
                java.io.StringWriter sw = new java.io.StringWriter();
                StreamResult sr = new StreamResult(sw);
                transformer.transform(domSource, sr);
                xml = sw.toString();


                } catch (Exception e) {
                        throw new ServletException(e);
                }
                return xml;
        }

}
1	package dk.thoerup.traininfoservice.banedk;
2
3	import java.io.IOException;
4	import java.util.List;
5	import java.util.logging.Level;
6	import java.util.logging.Logger;
7
8	import javax.servlet.ServletException;
9	import javax.servlet.http.HttpServlet;
10	import javax.servlet.http.HttpServletRequest;
11	import javax.servlet.http.HttpServletResponse;
12	import javax.xml.parsers.DocumentBuilder;
13	import javax.xml.parsers.DocumentBuilderFactory;
14	import javax.xml.transform.OutputKeys;
15	import javax.xml.transform.Transformer;
16	import javax.xml.transform.TransformerFactory;
17	import javax.xml.transform.dom.DOMSource;
18	import javax.xml.transform.stream.StreamResult;
19
20	import org.w3c.dom.DOMImplementation;
21	import org.w3c.dom.Document;
22	import org.w3c.dom.Element;
23
24	import dk.thoerup.circuitbreaker.CircuitBreakerException;
25	import dk.thoerup.traininfoservice.StationDAO;
26	import dk.thoerup.traininfoservice.Statistics;
27
28	/**
29	* Servlet implementation class DepartureServlet
30	*/
31	public class DepartureServlet extends HttpServlet {
32	private static final long serialVersionUID = 1L;
33
34	Logger logger = Logger.getLogger( DepartureServlet.class.getName() );
35
36	DepartureFetcher fetcher;
37	TransformerFactory transformerFactory = TransformerFactory.newInstance();
38	DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
39
40
41	@Override
42	public void init() throws ServletException {
43	super.init();
44
45	boolean useTempSite = Boolean.parseBoolean( getServletContext().getInitParameter("usetempsite") );
46	int cacheTimeout = Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
47	logger.info( "DepartureServlet, use temp site=" + useTempSite + ", cache=" + cacheTimeout);
48	fetcher = new DepartureFetcher(useTempSite, cacheTimeout);
49	}
50
51	@Override
52	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
53	if (req.getParameter("station") == null) {
54	resp.sendError(400, "not enough parameters");
55	return;
56	}
57	Statistics.getInstance().incrementDepartureLookups();
58
59	int station = Integer.parseInt( req.getParameter("station") );
60	String format = req.getParameter("format");
61
62	List<DepartureBean> beans;
63
64	String stationName = StationDAO.getStationName(station);
65
66	try {
67	beans = fetcher.cachedLookupDepartures(station);
68	} catch (java.io.IOException ioe) {
69	logger.warning("Read failed, station="+station + ". " + ioe.getMessage() );
70	Statistics.getInstance().incrementDepartureErrors();
71	resp.sendError(500);
72	return;
73	} catch (CircuitBreakerException cbe) {
74	logger.warning("Circuitbreaker - failing fast");
75	Statistics.getInstance().incrementDepartureErrors();
76	resp.sendError(500);
77	return;
78	} catch (Exception e) {
79	logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
80	Statistics.getInstance().incrementDepartureErrors();
81	resp.sendError(500);
82	return;
83	}
84
85	resp.setDateHeader("Expires", 0);
86	resp.setHeader("Cache-Control", "no-cache, must-revalidate");
87
88	if (format.equalsIgnoreCase("xml")) {
89	resp.setContentType("text/xml");
90	resp.getWriter().print( formatXml(beans, stationName) );
91	} else if (format.equalsIgnoreCase("html")) {
92
93	String advStr = req.getParameter("advanced");
94	boolean advanced = advStr != null ? Boolean.parseBoolean(advStr) : false;
95
96	req.setAttribute("advanced", advanced);
97	req.setAttribute("stationname", stationName );
98	req.setAttribute("departurebeans", beans);
99	req.setAttribute("stationID", station );
100	getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);
101	} else {
102	throw new ServletException("Unknown format");
103	}
104
105	}
106
107	protected String formatXml(List<DepartureBean> beans, String stationName) throws ServletException{
108	String xml = "";
109	try {
110	DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
111	DOMImplementation impl = builder.getDOMImplementation();
112
113
114	Document doc = impl.createDocument(null,null,null);
115	Element root = doc.createElement("departureinfo");
116	root.setAttribute("station", stationName);
117	for (DepartureBean departure : beans) {
118	Element train = doc.createElement("train");
119
120	Element time = doc.createElement("time");
121	time.setTextContent( departure.getTime() );
122	train.appendChild(time);
123
124	Element updated = doc.createElement("updated");
125	updated.setTextContent( String.valueOf(departure.getUpdated()) );
126	train.appendChild(updated);
127
128	Element trainNumber = doc.createElement("trainnumber");
129	trainNumber.setTextContent( departure.getTrainNumber() );
130	train.appendChild(trainNumber);
131
132	Element destination = doc.createElement("destination");
133	destination.setTextContent( departure.getDestination());
134	train.appendChild(destination);
135
136	Element origin = doc.createElement("origin");
137	origin.setTextContent( departure.getOrigin() );
138	train.appendChild(origin);
139
140	Element location= doc.createElement("location");
141	location.setTextContent( departure.getLocation() );
142	train.appendChild(location);
143
144	Element status = doc.createElement("status");
145	status.setTextContent( departure.getStatus() );
146	train.appendChild(status);
147
148	Element note = doc.createElement("note");
149	note.setTextContent( departure.getNote() );
150	train.appendChild(note);
151
152	Element type = doc.createElement("type");
153	type.setTextContent( departure.getType() );
154	train.appendChild(type);
155
156	root.appendChild(train);
157	}
158
159	doc.appendChild(root);
160
161
162	DOMSource domSource = new DOMSource(doc);
163
164	Transformer transformer = transformerFactory.newTransformer();
165	//transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
166	transformer.setOutputProperty(OutputKeys.METHOD, "xml");
167	transformer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
168	transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
169	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
170	java.io.StringWriter sw = new java.io.StringWriter();
171	StreamResult sr = new StreamResult(sw);
172	transformer.transform(domSource, sr);
173	xml = sw.toString();
174
175
176	} catch (Exception e) {
177	throw new ServletException(e);
178	}
179	return xml;
180	}
181
182	}