tim/prune/load/xml/GpxHandler.java

   1 package tim.prune.load.xml;
   2
   3 import java.util.ArrayList;
   4
   5 import org.xml.sax.Attributes;
   6 import org.xml.sax.SAXException;
   7
   8 import tim.prune.data.Field;
   9
  10
  11 /**
  12  * Class for handling specifics of parsing Gpx files
  13  */
  14 public class GpxHandler extends XmlHandler
  15 {
  16         private boolean _insideWaypoint = false;
  17         private boolean _insideName = false;
  18         private boolean _insideElevation = false;
  19         private boolean _insideTime = false;
  20         private boolean _insideType = false;
  21         private boolean _startSegment = true;
  22         private String _name = null, _latitude = null, _longitude = null;
  23         private String _elevation = null;
  24         private String _time = null;
  25         private String _type = null;
  26         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  27
  28         /**
  29          * Receive the start of a tag
  30          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  31          */
  32         public void startElement(String uri, String localName, String qName,
  33                 Attributes attributes) throws SAXException
  34         {
  35                 // Read the parameters for waypoints and track points
  36                 if (qName.equalsIgnoreCase("wpt") || qName.equalsIgnoreCase("trkpt") || qName.equalsIgnoreCase("rtept"))
  37                 {
  38                         _insideWaypoint = qName.equalsIgnoreCase("wpt");
  39                         int numAttributes = attributes.getLength();
  40                         for (int i=0; i<numAttributes; i++)
  41                         {
  42                                 String att = attributes.getQName(i);
  43                                 if (att.equals("lat")) {_latitude = attributes.getValue(i);}
  44                                 else if (att.equals("lon")) {_longitude = attributes.getValue(i);}
  45                         }
  46                         _elevation = null;
  47                         _name = null;
  48                         _time = null;
  49                         _type = null;
  50                 }
  51                 else if (qName.equalsIgnoreCase("ele"))
  52                 {
  53                         _insideElevation = true;
  54                 }
  55                 else if (qName.equalsIgnoreCase("name"))
  56                 {
  57                         _insideName = true;
  58                 }
  59                 else if (qName.equalsIgnoreCase("time"))
  60                 {
  61                         _insideTime = true;
  62                 }
  63                 else if (qName.equalsIgnoreCase("type"))
  64                 {
  65                         _insideType = true;
  66                 }
  67                 else if (qName.equalsIgnoreCase("trkseg"))
  68                 {
  69                         _startSegment = true;
  70                 }
  71                 super.startElement(uri, localName, qName, attributes);
  72         }
  73
  74
  75         /**
  76          * Process end tag
  77          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
  78          */
  79         public void endElement(String uri, String localName, String qName)
  80                 throws SAXException
  81         {
  82                 if (qName.equalsIgnoreCase("wpt") || qName.equalsIgnoreCase("trkpt") || qName.equalsIgnoreCase("rtept"))
  83                 {
  84                         processPoint();
  85                 }
  86                 else if (qName.equalsIgnoreCase("ele"))
  87                 {
  88                         _insideElevation = false;
  89                 }
  90                 else if (qName.equalsIgnoreCase("name"))
  91                 {
  92                         _insideName = false;
  93                 }
  94                 else if (qName.equalsIgnoreCase("time"))
  95                 {
  96                         _insideTime = false;
  97                 }
  98                 else if (qName.equalsIgnoreCase("type"))
  99                 {
 100                         _insideType = false;
 101                 }
 102                 super.endElement(uri, localName, qName);
 103         }
 104
 105
 106         /**
 107          * Process character text (inside tags or between them)
 108          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 109          */
 110         public void characters(char[] ch, int start, int length)
 111                 throws SAXException
 112         {
 113                 String value = new String(ch, start, length);
 114                 if (_insideName && _insideWaypoint) {_name = checkCharacters(_name, value);}
 115                 else if (_insideElevation) {_elevation = checkCharacters(_elevation, value);}
 116                 else if (_insideTime) {_time = checkCharacters(_time, value);}
 117                 else if (_insideType) {_type = checkCharacters(_type, value);}
 118                 super.characters(ch, start, length);
 119         }
 120
 121
 122         /**
 123          * Check to concatenate partially-received values, if necessary
 124          * @param inVariable variable containing characters received until now
 125          * @param inValue new value received
 126          * @return concatenation
 127          */
 128         private static String checkCharacters(String inVariable, String inValue)
 129         {
 130                 if (inVariable == null) {return inValue;}
 131                 return inVariable + inValue;
 132         }
 133
 134
 135         /**
 136          * Process a point, either a waypoint or track point
 137          */
 138         private void processPoint()
 139         {
 140                 // Put the values into a String array matching the order in getFieldArray()
 141                 String[] values = new String[7];
 142                 values[0] = _latitude; values[1] = _longitude;
 143                 values[2] = _elevation; values[3] = _name;
 144                 values[4] = _time;
 145                 if (_startSegment && !_insideWaypoint) {
 146                         values[5] = "1";
 147                         _startSegment = false;
 148                 }
 149                 values[6] = _type;
 150                 _pointList.add(values);
 151         }
 152
 153
 154         /**
 155          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 156          */
 157         public Field[] getFieldArray()
 158         {
 159                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 160                         Field.WAYPT_NAME, Field.TIMESTAMP, Field.NEW_SEGMENT, Field.WAYPT_TYPE};
 161                 return fields;
 162         }
 163
 164
 165         /**
 166          * Return the parsed information as a 2d array
 167          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 168          */
 169         public String[][] getDataArray()
 170         {
 171                 int numPoints = _pointList.size();
 172                 // construct data array
 173                 String[][] result = new String[numPoints][];
 174                 for (int i=0; i<numPoints; i++)
 175                 {
 176                         result[i] = _pointList.get(i);
 177                 }
 178                 return result;
 179         }
 180 }