tim/prune/load/xml/XmlFileLoader.java

   1 package tim.prune.load.xml;
   2
   3 import java.io.File;
   4 import java.io.FileInputStream;
   5 import java.io.FileNotFoundException;
   6 import java.io.IOException;
   7 import java.io.InputStream;
   8
   9 import javax.xml.parsers.SAXParser;
  10 import javax.xml.parsers.SAXParserFactory;
  11
  12 import org.xml.sax.Attributes;
  13 import org.xml.sax.InputSource;
  14 import org.xml.sax.SAXException;
  15 import org.xml.sax.XMLReader;
  16 import org.xml.sax.helpers.DefaultHandler;
  17 import org.xml.sax.helpers.XMLReaderFactory;
  18
  19 import tim.prune.App;
  20 import tim.prune.I18nManager;
  21 import tim.prune.data.SourceInfo;
  22 import tim.prune.load.MediaLinkInfo;
  23
  24 /**
  25  * Class for handling loading of Xml files, and passing the
  26  * loaded data back to the App object
  27  */
  28 public class XmlFileLoader extends DefaultHandler implements Runnable
  29 {
  30         private File _file = null;
  31         private App _app = null;
  32         private XmlHandler _handler = null;
  33         private String _unknownType = null;
  34
  35
  36         /**
  37          * Constructor
  38          * @param inApp Application object to inform of track load
  39          */
  40         public XmlFileLoader(App inApp)
  41         {
  42                 _app = inApp;
  43         }
  44
  45         /**
  46          * Reset the handler to ensure data cleared
  47          */
  48         public void reset()
  49         {
  50                 _handler = null;
  51                 _unknownType = null;
  52         }
  53
  54         /**
  55          * Open the selected file
  56          * @param inFile File to open
  57          */
  58         public void openFile(File inFile)
  59         {
  60                 _file = inFile;
  61                 reset();
  62                 // start new thread in case xml parsing is time-consuming
  63                 new Thread(this).start();
  64         }
  65
  66
  67         /**
  68          * Run method, to parse the file
  69          * @see java.lang.Runnable#run()
  70          */
  71         public void run()
  72         {
  73                 FileInputStream inStream = null;
  74                 boolean success = false;
  75                 try
  76                 {
  77                         inStream = new FileInputStream(_file);
  78                         success = parseXmlStream(inStream);
  79                 }
  80                 catch (FileNotFoundException fnfe) {}
  81
  82                 // Clean up the stream, don't need it any more
  83                 try {inStream.close();} catch (IOException e2) {}
  84
  85                 if (success)
  86                 {
  87                         // Check whether handler was properly instantiated
  88                         if (_handler == null)
  89                         {
  90                                 // Wasn't either kml or gpx
  91                                 _app.showErrorMessageNoLookup("error.load.dialogtitle",
  92                                         I18nManager.getText("error.load.unknownxml") + " " + _unknownType);
  93                         }
  94                         else
  95                         {
  96                                 // Pass information back to app
  97                                 SourceInfo sourceInfo = new SourceInfo(_file,
  98                                         (_handler instanceof GpxHandler?SourceInfo.FILE_TYPE.GPX:SourceInfo.FILE_TYPE.KML));
  99                                 _app.informDataLoaded(_handler.getFieldArray(), _handler.getDataArray(),
 100                                         null, sourceInfo, _handler.getTrackNameList(),
 101                                         new MediaLinkInfo(_handler.getLinkArray()));
 102                         }
 103                 }
 104         }
 105
 106
 107         /**
 108          * Try both Xerces and the built-in java classes to parse the given xml stream
 109          * @param inStream input stream from file / zip / gzip
 110          * @return true on success, false if both xerces and built-in parser failed
 111          */
 112         public boolean parseXmlStream(InputStream inStream)
 113         {
 114                 boolean success = false;
 115                 // Firstly, try to use xerces to parse the xml (will throw an exception if not available)
 116                 try
 117                 {
 118                         XMLReader xmlReader = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
 119                         xmlReader.setContentHandler(this);
 120                         xmlReader.parse(new InputSource(inStream));
 121                         success = true; // worked
 122                 }
 123                 catch (Exception e) {} // don't care too much if it didn't work, there's a backup
 124
 125                 // If that didn't work, try the built-in classes (which work for xml1.0 but handling for 1.1 contains bugs)
 126                 if (!success)
 127                 {
 128                         try
 129                         {
 130                                 // Construct a SAXParser and use this as a default handler
 131                                 SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
 132                                 saxParser.parse(inStream, this);
 133                                 success = true;
 134                         }
 135                         catch (Exception e)
 136                         {
 137                                 // Show error dialog
 138                                 _app.showErrorMessageNoLookup("error.load.dialogtitle",
 139                                         I18nManager.getText("error.load.othererror") + " " + e.getMessage());
 140                         }
 141                 }
 142                 return success;
 143         }
 144
 145         /**
 146          * Receive a tag
 147          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
 148          */
 149         public void startElement(String uri, String localName, String qName,
 150                 Attributes attributes) throws SAXException
 151         {
 152                 // Check for "kml" or "gpx" tags
 153                 if (_handler == null)
 154                 {
 155                         if (qName.equals("kml")) {_handler = new KmlHandler();}
 156                         else if (qName.equals("gpx")) {_handler = new GpxHandler();}
 157                         else if (_unknownType == null && !qName.equals(""))
 158                         {
 159                                 _unknownType = qName;
 160                         }
 161                 }
 162                 else
 163                 {
 164                         // Handler instantiated so pass tags on to it
 165                         _handler.startElement(uri, localName, qName, attributes);
 166                 }
 167                 super.startElement(uri, localName, qName, attributes);
 168         }
 169
 170
 171         /**
 172          * Receive characters, either between or inside tags
 173          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 174          */
 175         public void characters(char[] ch, int start, int length)
 176                 throws SAXException
 177         {
 178                 if (_handler != null)
 179                 {
 180                         // Handler instantiated so pass tags on to it
 181                         _handler.characters(ch, start, length);
 182                 }
 183                 super.characters(ch, start, length);
 184         }
 185
 186
 187         /**
 188          * Receive end of element
 189          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
 190          */
 191         public void endElement(String uri, String localName, String qName)
 192                 throws SAXException
 193         {
 194                 if (_handler != null)
 195                 {
 196                         // Handler instantiated so pass tags on to it
 197                         _handler.endElement(uri, localName, qName);
 198                 }
 199                 super.endElement(uri, localName, qName);
 200         }
 201
 202         /**
 203          * @return The Xml handler used for the parsing
 204          */
 205         public XmlHandler getHandler()
 206         {
 207                 return _handler;
 208         }
 209 }