traininfoservice/banedk/DepartureServlet.java

package dk.thoerup.traininfoservice.banedk;

import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
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.DBConnection;

/**
 * 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;
                }
                
                int station = Integer.parseInt( req.getParameter("station") );
                String format = req.getParameter("format");

                List<DepartureBean> beans;

                String stationName = getStationName(station);

                try {
                        beans = fetcher.cachedLookupDepartures(station);
                } catch (java.io.IOException ioe) {
                        logger.warning("Read failed, station="+station + ". " + ioe.getMessage() );
                        resp.sendError(500);
                        return;
                } catch (CircuitBreakerException cbe) {
                        logger.warning("Circuitbreaker - failing fast");
                        resp.sendError(500);
                        return;
                } catch (Exception e) {                 
                        logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
                        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")) {
                        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);
                        
                        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;
        }

        protected String getStationName(int stationID) {
                String station = "";

                Connection conn = null;
                try {
                        conn = DBConnection.getConnection();
                        Statement stmt = conn.createStatement();
                        ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
                        if (rs.next()) {
                                station = rs.getString(1);
                        }

                } catch (Exception e) { 
                } finally {
                        try {
                                if (conn != null && !conn.isClosed())
                                        conn.close();
                        } catch (Exception e) {}
                }

                return station;
        }

}
1	package dk.thoerup.traininfoservice.banedk;
2
3	import java.io.IOException;
4	import java.sql.Connection;
5	import java.sql.ResultSet;
6	import java.sql.Statement;
7	import java.util.List;
8	import java.util.logging.Level;
9	import java.util.logging.Logger;
10
11	import javax.servlet.ServletException;
12	import javax.servlet.http.HttpServlet;
13	import javax.servlet.http.HttpServletRequest;
14	import javax.servlet.http.HttpServletResponse;
15	import javax.xml.parsers.DocumentBuilder;
16	import javax.xml.parsers.DocumentBuilderFactory;
17	import javax.xml.transform.OutputKeys;
18	import javax.xml.transform.Transformer;
19	import javax.xml.transform.TransformerFactory;
20	import javax.xml.transform.dom.DOMSource;
21	import javax.xml.transform.stream.StreamResult;
22
23	import org.w3c.dom.DOMImplementation;
24	import org.w3c.dom.Document;
25	import org.w3c.dom.Element;
26
27	import dk.thoerup.circuitbreaker.CircuitBreakerException;
28	import dk.thoerup.traininfoservice.DBConnection;
29
30	/**
31	* Servlet implementation class DepartureServlet
32	*/
33	public class DepartureServlet extends HttpServlet {
34	private static final long serialVersionUID = 1L;
35
36	Logger logger = Logger.getLogger( DepartureServlet.class.getName() );
37
38	DepartureFetcher fetcher;
39	TransformerFactory transformerFactory = TransformerFactory.newInstance();
40	DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
41
42
43	@Override
44	public void init() throws ServletException {
45	super.init();
46
47	boolean useTempSite = Boolean.parseBoolean( getServletContext().getInitParameter("usetempsite") );
48	int cacheTimeout = Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
49	logger.info( "DepartureServlet, use temp site=" + useTempSite + ", cache=" + cacheTimeout);
50	fetcher = new DepartureFetcher(useTempSite, cacheTimeout);
51	}
52
53	@Override
54	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
55	if (req.getParameter("station") == null) {
56	resp.sendError(400, "not enough parameters");
57	return;
58	}
59
60	int station = Integer.parseInt( req.getParameter("station") );
61	String format = req.getParameter("format");
62
63	List<DepartureBean> beans;
64
65	String stationName = getStationName(station);
66
67	try {
68	beans = fetcher.cachedLookupDepartures(station);
69	} catch (java.io.IOException ioe) {
70	logger.warning("Read failed, station="+station + ". " + ioe.getMessage() );
71	resp.sendError(500);
72	return;
73	} catch (CircuitBreakerException cbe) {
74	logger.warning("Circuitbreaker - failing fast");
75	resp.sendError(500);
76	return;
77	} catch (Exception e) {
78	logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
79	resp.sendError(500);
80	return;
81	}
82
83	resp.setDateHeader("Expires", 0);
84	resp.setHeader("Cache-Control", "no-cache, must-revalidate");
85
86	if (format.equalsIgnoreCase("xml")) {
87	resp.setContentType("text/xml");
88	resp.getWriter().print( formatXml(beans, stationName) );
89	} else if (format.equalsIgnoreCase("html")) {
90	req.setAttribute("stationname", stationName );
91	req.setAttribute("departurebeans", beans);
92	req.setAttribute("stationID", station );
93	getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);
94	} else {
95	throw new ServletException("Unknown format");
96	}
97
98	}
99
100	protected String formatXml(List<DepartureBean> beans, String stationName) throws ServletException{
101	String xml = "";
102	try {
103	DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
104	DOMImplementation impl = builder.getDOMImplementation();
105
106
107	Document doc = impl.createDocument(null,null,null);
108	Element root = doc.createElement("departureinfo");
109	root.setAttribute("station", stationName);
110	for (DepartureBean departure : beans) {
111	Element train = doc.createElement("train");
112
113	Element time = doc.createElement("time");
114	time.setTextContent( departure.getTime() );
115	train.appendChild(time);
116
117	Element updated = doc.createElement("updated");
118	updated.setTextContent( String.valueOf(departure.getUpdated()) );
119	train.appendChild(updated);
120
121	Element trainNumber = doc.createElement("trainnumber");
122	trainNumber.setTextContent( departure.getTrainNumber() );
123	train.appendChild(trainNumber);
124
125	Element destination = doc.createElement("destination");
126	destination.setTextContent( departure.getDestination());
127	train.appendChild(destination);
128
129	Element origin = doc.createElement("origin");
130	origin.setTextContent( departure.getOrigin() );
131	train.appendChild(origin);
132
133	Element location= doc.createElement("location");
134	location.setTextContent( departure.getLocation() );
135	train.appendChild(location);
136
137	Element status = doc.createElement("status");
138	status.setTextContent( departure.getStatus() );
139	train.appendChild(status);
140
141	Element note = doc.createElement("note");
142	note.setTextContent( departure.getNote() );
143	train.appendChild(note);
144
145	root.appendChild(train);
146	}
147
148	doc.appendChild(root);
149
150
151	DOMSource domSource = new DOMSource(doc);
152
153	Transformer transformer = transformerFactory.newTransformer();
154	//transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
155	transformer.setOutputProperty(OutputKeys.METHOD, "xml");
156	transformer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
157	transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
158	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
159	java.io.StringWriter sw = new java.io.StringWriter();
160	StreamResult sr = new StreamResult(sw);
161	transformer.transform(domSource, sr);
162	xml = sw.toString();
163
164
165	} catch (Exception e) {
166	throw new ServletException(e);
167	}
168	return xml;
169	}
170
171	protected String getStationName(int stationID) {
172	String station = "";
173
174	Connection conn = null;
175	try {
176	conn = DBConnection.getConnection();
177	Statement stmt = conn.createStatement();
178	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
179	if (rs.next()) {
180	station = rs.getString(1);
181	}
182
183	} catch (Exception e) {
184	} finally {
185	try {
186	if (conn != null && !conn.isClosed())
187	conn.close();
188	} catch (Exception e) {}
189	}
190
191	return station;
192	}
193
194	}