tim/prune/load/NmeaFileLoader.java

   1 package tim.prune.load;
   2
   3 import java.io.BufferedReader;
   4 import java.io.File;
   5 import java.io.FileReader;
   6 import java.io.IOException;
   7 import java.util.ArrayList;
   8
   9 import tim.prune.App;
  10 import tim.prune.data.Altitude;
  11 import tim.prune.data.Field;
  12 import tim.prune.data.SourceInfo;
  13
  14 /**
  15  * Class to handle the loading of Nmea files
  16  */
  17 public class NmeaFileLoader
  18 {
  19         /** App for callback of file loading */
  20         private App _app = null;
  21
  22         /**
  23          * Constructor
  24          * @param inApp App object
  25          */
  26         public NmeaFileLoader(App inApp)
  27         {
  28                 _app = inApp;
  29         }
  30
  31         /**
  32          * Open the selected file
  33          * @param inFile File to open
  34          */
  35         public void openFile(File inFile)
  36         {
  37                 BufferedReader reader = null;
  38                 ArrayList<NmeaMessage> messages = new ArrayList<NmeaMessage>();
  39                 try
  40                 {
  41                         reader = new BufferedReader(new FileReader(inFile));
  42                         String currLine = reader.readLine();
  43                         boolean newSegment = true;
  44                         while (currLine != null)
  45                         {
  46                                 // Try to make an NmeaMessage object for each line of file
  47                                 if (currLine.trim().length() > 0)
  48                                 {
  49                                         NmeaMessage message = processLine(currLine);
  50                                         if (message != null)
  51                                         {
  52                                                 if (message.hasFix()) {
  53                                                         message.setSegment(newSegment);
  54                                                         // add message to list
  55                                                         messages.add(message);
  56                                                 }
  57                                                 // Start a new segment if fix lost
  58                                                 newSegment = !message.hasFix();
  59                                         }
  60                                 }
  61                                 // Read next line, if any
  62                                 currLine = reader.readLine();
  63                         }
  64                 }
  65                 catch (IOException ioe) {
  66                         _app.showErrorMessage("error.load.dialogtitle", "error.load.noread");
  67                 }
  68                 finally
  69                 {
  70                         // close file ignoring errors
  71                         try
  72                         {
  73                                 if (reader != null) reader.close();
  74                         }
  75                         catch (Exception e) {}
  76                 }
  77                 if (messages.size() > 0)
  78                 {
  79                         _app.informDataLoaded(getFieldArray(), makeDataArray(messages),
  80                                 Altitude.Format.METRES, new SourceInfo(inFile, SourceInfo.FILE_TYPE.NMEA));
  81                 }
  82         }
  83
  84         /**
  85          * Process the given NMEA line and return the message
  86          * @param inLine line to process
  87          * @return message object
  88          */
  89         private static NmeaMessage processLine(String inLine)
  90         {
  91                 // Only consider lines which are long enough and begin with the GPS position sentence
  92                 if (inLine == null || inLine.length() < 20 || !inLine.startsWith("$GPGGA")) {
  93                         return null;
  94                 }
  95                 // TODO: May be possible to pull date out of GPRMC messages, but then need to back-populate
  96                 // Assume comma delimiter, split into array
  97                 String[] splitLine = inLine.split(",");
  98                 if (splitLine != null && splitLine.length >= 10)
  99                 {
 100                         return new NmeaMessage(splitLine[2] + splitLine[3], // latitude
 101                                 splitLine[4] + splitLine[5], // longitude
 102                                 splitLine[9], // altitude
 103                                 splitLine[1], // timestamp
 104                                 splitLine[6]); // fix
 105                 }
 106                 // Couldn't parse it, return null
 107                 return null;
 108         }
 109
 110         /**
 111          * Make an object array from the data list
 112          * @param inList list of messages
 113          * @return object array for loading
 114          */
 115         private static Object[][] makeDataArray(ArrayList<NmeaMessage> inList)
 116         {
 117                 Object[][] result = new Object[inList.size()][];
 118                 for (int i=0; i<inList.size(); i++) {
 119                         result[i] = inList.get(i).getStrings();
 120                 }
 121                 return result;
 122         }
 123
 124         /**
 125          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 126          */
 127         public Field[] getFieldArray()
 128         {
 129                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 130                         Field.TIMESTAMP, Field.NEW_SEGMENT};
 131                 return fields;
 132         }
 133 }