tim/prune/load/xml/XmlFileLoader.java

   1 package tim.prune.load.xml;
   2
   3 import java.io.File;
   4 import javax.xml.parsers.SAXParser;
   5 import javax.xml.parsers.SAXParserFactory;
   6
   7 import org.xml.sax.Attributes;
   8 import org.xml.sax.SAXException;
   9 import org.xml.sax.helpers.DefaultHandler;
  10 import tim.prune.App;
  11 import tim.prune.I18nManager;
  12 import tim.prune.data.Altitude;
  13
  14 /**
  15  * Class for handling loading of Xml files, and passing the
  16  * loaded data back to the App object
  17  */
  18 public class XmlFileLoader extends DefaultHandler implements Runnable
  19 {
  20         private File _file = null;
  21         private App _app = null;
  22         private XmlHandler _handler = null;
  23         private String _unknownType = null;
  24
  25
  26         /**
  27          * Constructor
  28          * @param inApp Application object to inform of track load
  29          */
  30         public XmlFileLoader(App inApp)
  31         {
  32                 _app = inApp;
  33         }
  34
  35         /**
  36          * Reset the handler to ensure data cleared
  37          */
  38         public void reset()
  39         {
  40                 _handler = null;
  41                 _unknownType = null;
  42         }
  43
  44         /**
  45          * Open the selected file
  46          * @param inFile File to open
  47          */
  48         public void openFile(File inFile)
  49         {
  50                 _file = inFile;
  51                 reset();
  52                 // start new thread in case xml parsing is time-consuming
  53                 new Thread(this).start();
  54         }
  55
  56
  57         /**
  58          * Run method, to parse the file
  59          * @see java.lang.Runnable#run()
  60          */
  61         public void run()
  62         {
  63                 try
  64                 {
  65                         // Construct a SAXParser and use this as a default handler
  66                         SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
  67                         saxParser.parse(_file, this);
  68
  69                         // Check whether handler was properly instantiated
  70                         if (_handler == null)
  71                         {
  72                                 // Wasn't either kml or gpx
  73                                 _app.showErrorMessageNoLookup("error.load.dialogtitle",
  74                                         I18nManager.getText("error.load.unknownxml") + " " + _unknownType);
  75                         }
  76                         else
  77                         {
  78                                 // Pass information back to app
  79                                 _app.informDataLoaded(_handler.getFieldArray(), _handler.getDataArray(),
  80                                         Altitude.Format.METRES, _file.getName());
  81                         }
  82                 }
  83                 catch (Exception e)
  84                 {
  85                         // Show error dialog
  86                         _app.showErrorMessageNoLookup("error.load.dialogtitle",
  87                                 I18nManager.getText("error.load.othererror") + " " + e.getMessage());
  88                 }
  89         }
  90
  91
  92         /**
  93          * Receive a tag
  94          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  95          */
  96         public void startElement(String uri, String localName, String qName,
  97                 Attributes attributes) throws SAXException
  98         {
  99                 // Check for "kml" or "gpx" tags
 100                 if (_handler == null)
 101                 {
 102                         if (qName.equals("kml")) {_handler = new KmlHandler();}
 103                         else if (qName.equals("gpx")) {_handler = new GpxHandler();}
 104                         else if (_unknownType == null && !qName.equals(""))
 105                         {
 106                                 _unknownType = qName;
 107                         }
 108                 }
 109                 else
 110                 {
 111                         // Handler instantiated so pass tags on to it
 112                         _handler.startElement(uri, localName, qName, attributes);
 113                 }
 114                 super.startElement(uri, localName, qName, attributes);
 115         }
 116
 117
 118         /**
 119          * Receive characters, either between or inside tags
 120          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 121          */
 122         public void characters(char[] ch, int start, int length)
 123                 throws SAXException
 124         {
 125                 if (_handler != null)
 126                 {
 127                         // Handler instantiated so pass tags on to it
 128                         _handler.characters(ch, start, length);
 129                 }
 130                 super.characters(ch, start, length);
 131         }
 132
 133
 134         /**
 135          * Receive end of element
 136          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
 137          */
 138         public void endElement(String uri, String localName, String qName)
 139                 throws SAXException
 140         {
 141                 if (_handler != null)
 142                 {
 143                         // Handler instantiated so pass tags on to it
 144                         _handler.endElement(uri, localName, qName);
 145                 }
 146                 super.endElement(uri, localName, qName);
 147         }
 148
 149         /**
 150          * @return The Xml handler used for the parsing
 151          */
 152         public XmlHandler getHandler()
 153         {
 154                 return _handler;
 155         }
 156 }