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")) {
                        
                        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);
                        
                        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
91	String advStr = req.getParameter("advanced");
92	boolean advanced = advStr != null ? Boolean.parseBoolean(advStr) : false;
93
94	req.setAttribute("advanced", advanced);
95	req.setAttribute("stationname", stationName );
96	req.setAttribute("departurebeans", beans);
97	req.setAttribute("stationID", station );
98	getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);
99	} else {
100	throw new ServletException("Unknown format");
101	}
102
103	}
104
105	protected String formatXml(List<DepartureBean> beans, String stationName) throws ServletException{
106	String xml = "";
107	try {
108	DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
109	DOMImplementation impl = builder.getDOMImplementation();
110
111
112	Document doc = impl.createDocument(null,null,null);
113	Element root = doc.createElement("departureinfo");
114	root.setAttribute("station", stationName);
115	for (DepartureBean departure : beans) {
116	Element train = doc.createElement("train");
117
118	Element time = doc.createElement("time");
119	time.setTextContent( departure.getTime() );
120	train.appendChild(time);
121
122	Element updated = doc.createElement("updated");
123	updated.setTextContent( String.valueOf(departure.getUpdated()) );
124	train.appendChild(updated);
125
126	Element trainNumber = doc.createElement("trainnumber");
127	trainNumber.setTextContent( departure.getTrainNumber() );
128	train.appendChild(trainNumber);
129
130	Element destination = doc.createElement("destination");
131	destination.setTextContent( departure.getDestination());
132	train.appendChild(destination);
133
134	Element origin = doc.createElement("origin");
135	origin.setTextContent( departure.getOrigin() );
136	train.appendChild(origin);
137
138	Element location= doc.createElement("location");
139	location.setTextContent( departure.getLocation() );
140	train.appendChild(location);
141
142	Element status = doc.createElement("status");
143	status.setTextContent( departure.getStatus() );
144	train.appendChild(status);
145
146	Element note = doc.createElement("note");
147	note.setTextContent( departure.getNote() );
148	train.appendChild(note);
149
150	root.appendChild(train);
151	}
152
153	doc.appendChild(root);
154
155
156	DOMSource domSource = new DOMSource(doc);
157
158	Transformer transformer = transformerFactory.newTransformer();
159	//transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
160	transformer.setOutputProperty(OutputKeys.METHOD, "xml");
161	transformer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
162	transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
163	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
164	java.io.StringWriter sw = new java.io.StringWriter();
165	StreamResult sr = new StreamResult(sw);
166	transformer.transform(domSource, sr);
167	xml = sw.toString();
168
169
170	} catch (Exception e) {
171	throw new ServletException(e);
172	}
173	return xml;
174	}
175
176	protected String getStationName(int stationID) {
177	String station = "";
178
179	Connection conn = null;
180	try {
181	conn = DBConnection.getConnection();
182	Statement stmt = conn.createStatement();
183	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
184	if (rs.next()) {
185	station = rs.getString(1);
186	}
187
188	} catch (Exception e) {
189	} finally {
190	try {
191	if (conn != null && !conn.isClosed())
192	conn.close();
193	} catch (Exception e) {}
194	}
195
196	return station;
197	}
198
199	}