src/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.Field;
  11 import tim.prune.data.SourceInfo;
  12
  13 /**
  14  * Class to handle the loading of Nmea files
  15  */
  16 public class NmeaFileLoader
  17 {
  18         /** App for callback of file loading */
  19         private App _app = null;
  20
  21         /**
  22          * Constructor
  23          * @param inApp App object
  24          */
  25         public NmeaFileLoader(App inApp)
  26         {
  27                 _app = inApp;
  28         }
  29
  30         /**
  31          * Open the selected file
  32          * @param inFile File to open
  33          */
  34         public void openFile(File inFile)
  35         {
  36                 BufferedReader reader = null;
  37                 ArrayList<NmeaMessage> messages = new ArrayList<NmeaMessage>();
  38                 String lastDate = null;
  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 = processGGA(currLine);
  50                                         if (message != null)
  51                                         {
  52                                                 if (message.hasFix())
  53                                                 {
  54                                                         message.setSegment(newSegment);
  55                                                         message.setDate(lastDate);
  56                                                         // add message to list
  57                                                         messages.add(message);
  58                                                 }
  59                                                 // Start a new segment if fix lost
  60                                                 newSegment = !message.hasFix();
  61                                         }
  62                                         else {
  63                                                 String date = getDateFromRMC(currLine);
  64                                                 if (date != null)
  65                                                 {
  66                                                         if (lastDate == null && !messages.isEmpty()) {
  67                                                                 // Backfill first few messages received before the first date
  68                                                                 for (int m=0; m<messages.size(); m++) {
  69                                                                         messages.get(m).setDate(date);
  70                                                                 }
  71                                                         }
  72                                                         lastDate = date;
  73                                                 }
  74                                         }
  75                                 }
  76                                 // Read next line, if any
  77                                 currLine = reader.readLine();
  78                         }
  79                 }
  80                 catch (IOException ioe) {
  81                         _app.showErrorMessage("error.load.dialogtitle", "error.load.noread");
  82                 }
  83                 finally
  84                 {
  85                         // close file ignoring errors
  86                         try {
  87                                 if (reader != null) reader.close();
  88                         }
  89                         catch (Exception e) {}
  90                 }
  91                 if (messages.size() > 0)
  92                 {
  93                         _app.informDataLoaded(getFieldArray(), makeDataArray(messages),
  94                                 null, new SourceInfo(inFile, SourceInfo.FILE_TYPE.NMEA), null);
  95                 }
  96         }
  97
  98         /**
  99          * Process the given GGA sentence and return the message
 100          * @param inLine line to process
 101          * @return message object
 102          */
 103         private static NmeaMessage processGGA(String inLine)
 104         {
 105                 // Only consider lines which are long enough and begin with the GPS position sentence
 106                 if (inLine == null || inLine.length() < 20 || !inLine.startsWith("$GPGGA")) {
 107                         return null;
 108                 }
 109                 // Assume comma delimiter, split into array
 110                 String[] splitLine = inLine.split(",");
 111                 if (splitLine != null && splitLine.length >= 10)
 112                 {
 113                         return new NmeaMessage(splitLine[2] + splitLine[3], // latitude
 114                                 splitLine[4] + splitLine[5], // longitude
 115                                 splitLine[9], // altitude
 116                                 splitLine[1], // timestamp
 117                                 splitLine[6]); // fix
 118                 }
 119                 // Couldn't parse it, return null
 120                 return null;
 121         }
 122
 123         /**
 124          * Process the given MRC sentence and return the date
 125          * @param inLine line to process
 126          * @return date, if any
 127          */
 128         private static String getDateFromRMC(String inLine)
 129         {
 130                 // Only consider lines which are long enough and begin with the RMC sentence
 131                 if (inLine == null || inLine.length() < 20 || !inLine.startsWith("$GPRMC")) {
 132                         return null;
 133                 }
 134                 // Assume comma delimiter, split into array
 135                 String[] splitLine = inLine.split(",");
 136                 if (splitLine != null && splitLine.length >= 10)
 137                 {
 138                         return splitLine[9]; // date in position 9
 139                 }
 140                 // Couldn't parse it, return null
 141                 return null;
 142         }
 143
 144         /**
 145          * Make an object array from the data list
 146          * @param inList list of messages
 147          * @return object array for loading
 148          */
 149         private static Object[][] makeDataArray(ArrayList<NmeaMessage> inList)
 150         {
 151                 Object[][] result = new Object[inList.size()][];
 152                 for (int i=0; i<inList.size(); i++) {
 153                         result[i] = inList.get(i).getStrings();
 154                 }
 155                 return result;
 156         }
 157
 158         /**
 159          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 160          */
 161         public Field[] getFieldArray()
 162         {
 163                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 164                         Field.TIMESTAMP, Field.NEW_SEGMENT};
 165                 return fields;
 166         }
 167 }