tim/prune/save/xml/GpxCacher.java

   1 package tim.prune.save.xml;
   2
   3 import java.io.BufferedInputStream;
   4 import java.io.File;
   5 import java.io.FileInputStream;
   6 import java.io.InputStream;
   7 import java.util.zip.GZIPInputStream;
   8 import java.util.zip.ZipEntry;
   9 import java.util.zip.ZipInputStream;
  10
  11 import tim.prune.data.DataPoint;
  12 import tim.prune.data.SourceInfo;
  13
  14 /**
  15  * Class to read in a GPX file and cache all the point strings
  16  */
  17 public class GpxCacher implements TagReceiver
  18 {
  19         private SourceInfo _sourceInfo = null;
  20         private String _headerString = null;
  21         private String[] _strings = null;
  22         private int _pointNum = 0;
  23
  24
  25         /**
  26          * Constructor
  27          * @param inSourceInfo source information
  28          */
  29         public GpxCacher(SourceInfo inInfo)
  30         {
  31                 _sourceInfo = inInfo;
  32                 _strings = new String[inInfo.getNumPoints()];
  33                 _pointNum = 0;
  34                 // Should be a gpx file, but might be raw, zipped or gzipped
  35                 File gpxFile = inInfo.getFile();
  36                 String fileName = gpxFile.getName().toLowerCase();
  37                 if (gpxFile.exists() && gpxFile.canRead())
  38                 {
  39                         GpxSlicer slicer = new GpxSlicer(this);
  40                         InputStream istream = null;
  41                         BufferedInputStream bstream = null;
  42                         try {
  43                                 if (fileName.endsWith(".gpx") || fileName.endsWith(".xml")) {
  44                                         istream = new FileInputStream(inInfo.getFile());
  45                                 }
  46                                 else if (fileName.endsWith(".zip")) {
  47                                         istream = getZipInputStream(inInfo.getFile());
  48                                 }
  49                                 else if (fileName.endsWith(".gz")) {
  50                                         istream = new GZIPInputStream(new FileInputStream(inInfo.getFile()));
  51                                 }
  52                                 else {
  53                                         System.out.println("GpxCacher unrecognised file type: " + inInfo.getFile().getName());
  54                                 }
  55                                 if (istream != null) {
  56                                         bstream = new BufferedInputStream(istream);
  57                                         slicer.slice(bstream);
  58                                         bstream.close();
  59                                 }
  60                         } catch (Exception e) {
  61                                 // TODO: Handle errors here with a list of warnings?
  62                                 e.printStackTrace();
  63                         }
  64                 }
  65         }
  66
  67         /**
  68          * Accept a tag from the slicer
  69          */
  70         public void reportTag(String inTag)
  71         {
  72                 if (_headerString == null) {
  73                         _headerString = inTag;
  74                 }
  75                 else if (_strings != null)
  76                 {
  77                         if (_pointNum < _strings.length)
  78                         {
  79                                 _strings[_pointNum] = inTag;
  80                                 _pointNum++;
  81                         }
  82                         else
  83                         {
  84                                 // _pointNum has got too high for the strings array
  85                                 // This means the cacher has failed, probably by invalid points - need to give up caching here
  86                                 _strings = null;
  87                         }
  88                 }
  89         }
  90
  91
  92         /**
  93          * @return the header string from the GPX tag
  94          */
  95         public String getHeaderString()
  96         {
  97                 return _headerString;
  98         }
  99
 100         /**
 101          * Get the source string for the given point
 102          * @param inPoint point to retrieve
 103          * @return string if found, otherwise null
 104          */
 105         public String getSourceString(DataPoint inPoint)
 106         {
 107                 int index = _sourceInfo.getIndex(inPoint);
 108                 if (_strings != null && index >= 0 && index < _strings.length) {
 109                         return _strings[index];
 110                 }
 111                 return null;
 112         }
 113
 114         /**
 115          * Get an inputstream of a GPX file inside a zip
 116          * @param inFile File object describing zip file
 117          * @return input stream for Xml parser
 118          */
 119         private static InputStream getZipInputStream(File inFile)
 120         {
 121                 try
 122                 {
 123                         ZipInputStream zis = new ZipInputStream(new FileInputStream(inFile));
 124                         while (zis.available() > 0)
 125                         {
 126                                 ZipEntry entry = zis.getNextEntry();
 127                                 String entryName = entry.toString();
 128                                 if (entryName != null && entryName.length() > 4)
 129                                 {
 130                                         String suffix = entryName.substring(entryName.length()-4).toLowerCase();
 131                                         if (suffix.equals(".gpx") || suffix.equals(".xml")) {
 132                                                 // First matching file so must be gpx
 133                                                 return zis;
 134                                         }
 135                                 }
 136                         }
 137                 }
 138                 catch (Exception e) {} // ignore errors
 139                 // not found - error!
 140                 return null;
 141         }
 142 }