traininfo/provider/XmlMetroProvider.java

package dk.thoerup.traininfo.provider;

import java.io.StringReader;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

import android.util.Log;

import dk.thoerup.traininfo.util.AndroidTimeoutCache;
import dk.thoerup.traininfo.util.DownloadUtil;
import dk.thoerup.traininfo.util.XmlUtil;

public class XmlMetroProvider implements MetroProvider {
        
        final int CACHE_TIMEOUT = 60000;

        AndroidTimeoutCache<Integer,MetroBean> metroCache = new AndroidTimeoutCache<Integer,MetroBean>(CACHE_TIMEOUT);
        

        @Override
        public MetroBean lookupMetroInfo(int stationID) {
                
                MetroBean metro = metroCache.get(stationID);
        
                if (metro == null) {                    
                        metro = lookupMetroWorker(stationID);
                        
                        if (metro != null) {                    
                                metroCache.put(stationID, metro);
                        }
                        
                } else {
                        Log.i("XmlDepartureProvider", "cache hit !!!");
                }               
                
                return metro;
        }
        
        
        private MetroBean lookupMetroWorker(int stationID) {

                try
                {       
                        String url = XmlUtil.SERVICE_BASE + "/MetroServlet?station=" + stationID;
                        Log.i("xmlurl",url);
                        String doc =  DownloadUtil.getContentString(url, 15000, "ISO-8859-1");
                        
                        InputSource source = new InputSource( new StringReader(doc));
                        
                        SAXParserFactory spf = SAXParserFactory.newInstance();
            SAXParser sp = spf.newSAXParser();
            XMLReader xr = sp.getXMLReader();

            MetroParser metroParser = new MetroParser();
                        xr.setContentHandler(metroParser);
                        xr.setErrorHandler(metroParser);
                        xr.parse(source);
                        
                        return metroParser.getMetroDepartures();
                        
                } catch (Exception e) {
                        Log.e("XmlMetroProvider", "lookupFunction", e);
                        return null;
                }               
        }
        
        
        class MetroParser extends DefaultHandler { 
                
                StringBuilder builder = new StringBuilder(256);
                private MetroBean metro = new MetroBean();
                
                MetroEntry tempEntry = new MetroEntry();

                public MetroBean getMetroDepartures() {
                        return metro;
                }
                                
        
                // this can be called several times fore the same text-node if there are many chardata / lines
                @Override
                public void characters (char ch[], int start, int length) 
                {               
                        builder.append(ch, start, length);
                }
                
                @Override
                public void startElement (String uri, String name, String qName, Attributes atts)throws SAXException
                {
                        if (name.equalsIgnoreCase("entry"))
                                tempEntry = new MetroEntry();
                        
                        builder.setLength(0); //reset StringBuilder
                }
                
                @Override
                public void endElement (String uri, String name, String qName) throws SAXException
                {
                        String str = builder.toString().trim();
                        
                        if (name.equals("entry")) {                     
                                metro.entries.add( tempEntry );                         
                        } else if (name.equals("head")) {
                                metro.head = str;                               
                        } else if (name.equals("operations")) {
                                metro.operationInfo = str;                              
                        } else if (name.equals("metro")) {
                                tempEntry.metro = str;
                        } else if (name.equals("destination")) {
                                tempEntry.destination = str;
                        } else if (name.equals("minutes")) {
                                tempEntry.minutes = str;
                        } else if (name.equals("plan")) {
                                metro.plan = str;
                        } 
                }
        }
        
}
1	package dk.thoerup.traininfo.provider;
2
3	import java.io.StringReader;
4
5	import javax.xml.parsers.SAXParser;
6	import javax.xml.parsers.SAXParserFactory;
7
8	import org.xml.sax.Attributes;
9	import org.xml.sax.InputSource;
10	import org.xml.sax.SAXException;
11	import org.xml.sax.XMLReader;
12	import org.xml.sax.helpers.DefaultHandler;
13
14	import android.util.Log;
15
16	import dk.thoerup.traininfo.util.AndroidTimeoutCache;
17	import dk.thoerup.traininfo.util.DownloadUtil;
18	import dk.thoerup.traininfo.util.XmlUtil;
19
20	public class XmlMetroProvider implements MetroProvider {
21
22	final int CACHE_TIMEOUT = 60000;
23
24	AndroidTimeoutCache<Integer,MetroBean> metroCache = new AndroidTimeoutCache<Integer,MetroBean>(CACHE_TIMEOUT);
25
26
27	@Override
28	public MetroBean lookupMetroInfo(int stationID) {
29
30	MetroBean metro = metroCache.get(stationID);
31
32	if (metro == null) {
33	metro = lookupMetroWorker(stationID);
34
35	if (metro != null) {
36	metroCache.put(stationID, metro);
37	}
38
39	} else {
40	Log.i("XmlDepartureProvider", "cache hit !!!");
41	}
42
43	return metro;
44	}
45
46
47	private MetroBean lookupMetroWorker(int stationID) {
48
49	try
50	{
51	String url = XmlUtil.SERVICE_BASE + "/MetroServlet?station=" + stationID;
52	Log.i("xmlurl",url);
53	String doc = DownloadUtil.getContentString(url, 15000, "ISO-8859-1");
54
55	InputSource source = new InputSource( new StringReader(doc));
56
57	SAXParserFactory spf = SAXParserFactory.newInstance();
58	SAXParser sp = spf.newSAXParser();
59	XMLReader xr = sp.getXMLReader();
60
61	MetroParser metroParser = new MetroParser();
62	xr.setContentHandler(metroParser);
63	xr.setErrorHandler(metroParser);
64	xr.parse(source);
65
66	return metroParser.getMetroDepartures();
67
68	} catch (Exception e) {
69	Log.e("XmlMetroProvider", "lookupFunction", e);
70	return null;
71	}
72	}
73
74
75	class MetroParser extends DefaultHandler {
76
77	StringBuilder builder = new StringBuilder(256);
78	private MetroBean metro = new MetroBean();
79
80	MetroEntry tempEntry = new MetroEntry();
81
82	public MetroBean getMetroDepartures() {
83	return metro;
84	}
85
86
87	// this can be called several times fore the same text-node if there are many chardata / lines
88	@Override
89	public void characters (char ch[], int start, int length)
90	{
91	builder.append(ch, start, length);
92	}
93
94	@Override
95	public void startElement (String uri, String name, String qName, Attributes atts)throws SAXException
96	{
97	if (name.equalsIgnoreCase("entry"))
98	tempEntry = new MetroEntry();
99
100	builder.setLength(0); //reset StringBuilder
101	}
102
103	@Override
104	public void endElement (String uri, String name, String qName) throws SAXException
105	{
106	String str = builder.toString().trim();
107
108	if (name.equals("entry")) {
109	metro.entries.add( tempEntry );
110	} else if (name.equals("head")) {
111	metro.head = str;
112	} else if (name.equals("operations")) {
113	metro.operationInfo = str;
114	} else if (name.equals("metro")) {
115	tempEntry.metro = str;
116	} else if (name.equals("destination")) {
117	tempEntry.destination = str;
118	} else if (name.equals("minutes")) {
119	tempEntry.minutes = str;
120	} else if (name.equals("plan")) {
121	metro.plan = str;
122	}
123	}
124	}
125
126	}