| 1 | //License: GPL. Copyright 2008 by Christoph Brill |
|---|
| 2 | |
|---|
| 3 | package org.openstreetmap.josm.io; |
|---|
| 4 | |
|---|
| 5 | import java.io.BufferedReader; |
|---|
| 6 | import java.io.File; |
|---|
| 7 | import java.io.IOException; |
|---|
| 8 | import java.io.InputStream; |
|---|
| 9 | import java.io.InputStreamReader; |
|---|
| 10 | import java.text.ParsePosition; |
|---|
| 11 | import java.text.SimpleDateFormat; |
|---|
| 12 | import java.util.ArrayList; |
|---|
| 13 | import java.util.Collection; |
|---|
| 14 | import java.util.Collections; |
|---|
| 15 | import java.util.Date; |
|---|
| 16 | |
|---|
| 17 | import org.openstreetmap.josm.data.coor.LatLon; |
|---|
| 18 | import org.openstreetmap.josm.data.gpx.GpxData; |
|---|
| 19 | import org.openstreetmap.josm.data.gpx.ImmutableGpxTrack; |
|---|
| 20 | import org.openstreetmap.josm.data.gpx.WayPoint; |
|---|
| 21 | import org.openstreetmap.josm.tools.DateUtils; |
|---|
| 22 | |
|---|
| 23 | /** |
|---|
| 24 | * Read a nmea file. Based on information from |
|---|
| 25 | * http://www.kowoma.de/gps/zusatzerklaerungen/NMEA.htm |
|---|
| 26 | * |
|---|
| 27 | * @author cbrill |
|---|
| 28 | */ |
|---|
| 29 | public class NmeaReader { |
|---|
| 30 | |
|---|
| 31 | /** Handler for the different types that NMEA speaks. */ |
|---|
| 32 | public static enum NMEA_TYPE { |
|---|
| 33 | |
|---|
| 34 | /** RMC = recommended minimum sentence C. */ |
|---|
| 35 | GPRMC("$GPRMC"), |
|---|
| 36 | /** GPS positions. */ |
|---|
| 37 | GPGGA("$GPGGA"), |
|---|
| 38 | /** SA = satellites active. */ |
|---|
| 39 | GPGSA("$GPGSA"), |
|---|
| 40 | /** Course over ground and ground speed */ |
|---|
| 41 | GPVTG("$GPVTG"); |
|---|
| 42 | |
|---|
| 43 | private final String type; |
|---|
| 44 | |
|---|
| 45 | NMEA_TYPE(String type) { |
|---|
| 46 | this.type = type; |
|---|
| 47 | } |
|---|
| 48 | |
|---|
| 49 | public String getType() { |
|---|
| 50 | return this.type; |
|---|
| 51 | } |
|---|
| 52 | |
|---|
| 53 | public boolean equals(String type) { |
|---|
| 54 | return this.type.equals(type); |
|---|
| 55 | } |
|---|
| 56 | } |
|---|
| 57 | |
|---|
| 58 | // GPVTG |
|---|
| 59 | public static enum GPVTG { |
|---|
| 60 | COURSE(1),COURSE_REF(2), // true course |
|---|
| 61 | COURSE_M(3), COURSE_M_REF(4), // magnetic course |
|---|
| 62 | SPEED_KN(5), SPEED_KN_UNIT(6), // speed in knots |
|---|
| 63 | SPEED_KMH(7), SPEED_KMH_UNIT(8), // speed in km/h |
|---|
| 64 | REST(9); // version-specific rest |
|---|
| 65 | |
|---|
| 66 | public final int position; |
|---|
| 67 | |
|---|
| 68 | GPVTG(int position) { |
|---|
| 69 | this.position = position; |
|---|
| 70 | } |
|---|
| 71 | } |
|---|
| 72 | |
|---|
| 73 | // The following only applies to GPRMC |
|---|
| 74 | public static enum GPRMC { |
|---|
| 75 | TIME(1), |
|---|
| 76 | /** Warning from the receiver (A = data ok, V = warning) */ |
|---|
| 77 | RECEIVER_WARNING(2), |
|---|
| 78 | WIDTH_NORTH(3), WIDTH_NORTH_NAME(4), // Latitude, NS |
|---|
| 79 | LENGTH_EAST(5), LENGTH_EAST_NAME(6), // Longitude, EW |
|---|
| 80 | SPEED(7), COURSE(8), DATE(9), // Speed in knots |
|---|
| 81 | MAGNETIC_DECLINATION(10), UNKNOWN(11), // magnetic declination |
|---|
| 82 | /** |
|---|
| 83 | * Mode (A = autonom; D = differential; E = estimated; N = not valid; S |
|---|
| 84 | * = simulated) |
|---|
| 85 | * |
|---|
| 86 | * @since NMEA 2.3 |
|---|
| 87 | */ |
|---|
| 88 | MODE(12); |
|---|
| 89 | |
|---|
| 90 | public final int position; |
|---|
| 91 | |
|---|
| 92 | GPRMC(int position) { |
|---|
| 93 | this.position = position; |
|---|
| 94 | } |
|---|
| 95 | } |
|---|
| 96 | |
|---|
| 97 | // The following only applies to GPGGA |
|---|
| 98 | public static enum GPGGA { |
|---|
| 99 | TIME(1), LATITUDE(2), LATITUDE_NAME(3), LONGITUDE(4), LONGITUDE_NAME(5), |
|---|
| 100 | /** |
|---|
| 101 | * Quality (0 = invalid, 1 = GPS, 2 = DGPS, 6 = estimanted (@since NMEA |
|---|
| 102 | * 2.3)) |
|---|
| 103 | */ |
|---|
| 104 | QUALITY(6), SATELLITE_COUNT(7), |
|---|
| 105 | HDOP(8), // HDOP (horizontal dilution of precision) |
|---|
| 106 | HEIGHT(9), HEIGHT_UNTIS(10), // height above NN (above geoid) |
|---|
| 107 | HEIGHT_2(11), HEIGHT_2_UNTIS(12), // height geoid - height ellipsoid (WGS84) |
|---|
| 108 | GPS_AGE(13),// Age of differential GPS data |
|---|
| 109 | REF(14); // REF station |
|---|
| 110 | |
|---|
| 111 | public final int position; |
|---|
| 112 | GPGGA(int position) { |
|---|
| 113 | this.position = position; |
|---|
| 114 | } |
|---|
| 115 | } |
|---|
| 116 | |
|---|
| 117 | public static enum GPGSA { |
|---|
| 118 | AUTOMATIC(1), |
|---|
| 119 | FIX_TYPE(2), // 1 = not fixed, 2 = 2D fixed, 3 = 3D fixed) |
|---|
| 120 | // PRN numbers for max 12 satellites |
|---|
| 121 | PRN_1(3), PRN_2(4), PRN_3(5), PRN_4(6), PRN_5(7), PRN_6(8), |
|---|
| 122 | PRN_7(9), PRN_8(10), PRN_9(11), PRN_10(12), PRN_11(13), PRN_12(14), |
|---|
| 123 | PDOP(15), // PDOP (precision) |
|---|
| 124 | HDOP(16), // HDOP (horizontal precision) |
|---|
| 125 | VDOP(17), ; // VDOP (vertical precision) |
|---|
| 126 | |
|---|
| 127 | public final int position; |
|---|
| 128 | GPGSA(int position) { |
|---|
| 129 | this.position = position; |
|---|
| 130 | } |
|---|
| 131 | } |
|---|
| 132 | |
|---|
| 133 | public GpxData data; |
|---|
| 134 | |
|---|
| 135 | // private final static SimpleDateFormat GGATIMEFMT = |
|---|
| 136 | // new SimpleDateFormat("HHmmss.SSS"); |
|---|
| 137 | private final static SimpleDateFormat RMCTIMEFMT = |
|---|
| 138 | new SimpleDateFormat("ddMMyyHHmmss.SSS"); |
|---|
| 139 | private final static SimpleDateFormat RMCTIMEFMTSTD = |
|---|
| 140 | new SimpleDateFormat("ddMMyyHHmmss"); |
|---|
| 141 | |
|---|
| 142 | private Date readTime(String p) |
|---|
| 143 | { |
|---|
| 144 | Date d = RMCTIMEFMT.parse(p, new ParsePosition(0)); |
|---|
| 145 | if (d == null) { |
|---|
| 146 | d = RMCTIMEFMTSTD.parse(p, new ParsePosition(0)); |
|---|
| 147 | } |
|---|
| 148 | if (d == null) |
|---|
| 149 | throw new RuntimeException("Date is malformed"); // malformed |
|---|
| 150 | return d; |
|---|
| 151 | } |
|---|
| 152 | |
|---|
| 153 | // functons for reading the error stats |
|---|
| 154 | public NMEAParserState ps; |
|---|
| 155 | |
|---|
| 156 | public int getParserUnknown() { |
|---|
| 157 | return ps.unknown; |
|---|
| 158 | } |
|---|
| 159 | public int getParserZeroCoordinates() { |
|---|
| 160 | return ps.zero_coord; |
|---|
| 161 | } |
|---|
| 162 | public int getParserChecksumErrors() { |
|---|
| 163 | return ps.checksum_errors+ps.no_checksum; |
|---|
| 164 | } |
|---|
| 165 | public int getParserMalformed() { |
|---|
| 166 | return ps.malformed; |
|---|
| 167 | } |
|---|
| 168 | public int getNumberOfCoordinates() { |
|---|
| 169 | return ps.success; |
|---|
| 170 | } |
|---|
| 171 | |
|---|
| 172 | public NmeaReader(InputStream source, File relativeMarkerPath) { |
|---|
| 173 | |
|---|
| 174 | // create the data tree |
|---|
| 175 | data = new GpxData(); |
|---|
| 176 | Collection<Collection<WayPoint>> currentTrack = new ArrayList<Collection<WayPoint>>(); |
|---|
| 177 | |
|---|
| 178 | try { |
|---|
| 179 | BufferedReader rd = |
|---|
| 180 | new BufferedReader(new InputStreamReader(source)); |
|---|
| 181 | |
|---|
| 182 | StringBuffer sb = new StringBuffer(1024); |
|---|
| 183 | int loopstart_char = rd.read(); |
|---|
| 184 | ps = new NMEAParserState(); |
|---|
| 185 | if(loopstart_char == -1) |
|---|
| 186 | //TODO tell user about the problem? |
|---|
| 187 | return; |
|---|
| 188 | sb.append((char)loopstart_char); |
|---|
| 189 | ps.p_Date="010100"; // TODO date problem |
|---|
| 190 | while(true) { |
|---|
| 191 | // don't load unparsable files completely to memory |
|---|
| 192 | if(sb.length()>=1020) { |
|---|
| 193 | sb.delete(0, sb.length()-1); |
|---|
| 194 | } |
|---|
| 195 | int c = rd.read(); |
|---|
| 196 | if(c=='$') { |
|---|
| 197 | ParseNMEASentence(sb.toString(), ps); |
|---|
| 198 | sb.delete(0, sb.length()); |
|---|
| 199 | sb.append('$'); |
|---|
| 200 | } else if(c == -1) { |
|---|
| 201 | // EOF: add last WayPoint if it works out |
|---|
| 202 | ParseNMEASentence(sb.toString(),ps); |
|---|
| 203 | break; |
|---|
| 204 | } else { |
|---|
| 205 | sb.append((char)c); |
|---|
| 206 | } |
|---|
| 207 | } |
|---|
| 208 | rd.close(); |
|---|
| 209 | currentTrack.add(ps.waypoints); |
|---|
| 210 | data.tracks.add(new ImmutableGpxTrack(currentTrack, Collections.<String, Object>emptyMap())); |
|---|
| 211 | |
|---|
| 212 | } catch (final IOException e) { |
|---|
| 213 | // TODO tell user about the problem? |
|---|
| 214 | } |
|---|
| 215 | } |
|---|
| 216 | private static class NMEAParserState { |
|---|
| 217 | protected Collection<WayPoint> waypoints = new ArrayList<WayPoint>(); |
|---|
| 218 | protected String p_Time; |
|---|
| 219 | protected String p_Date; |
|---|
| 220 | protected WayPoint p_Wp; |
|---|
| 221 | |
|---|
| 222 | protected int success = 0; // number of successfully parsend sentences |
|---|
| 223 | protected int malformed = 0; |
|---|
| 224 | protected int checksum_errors = 0; |
|---|
| 225 | protected int no_checksum = 0; |
|---|
| 226 | protected int unknown = 0; |
|---|
| 227 | protected int zero_coord = 0; |
|---|
| 228 | } |
|---|
| 229 | |
|---|
| 230 | // Parses split up sentences into WayPoints which are stored |
|---|
| 231 | // in the collection in the NMEAParserState object. |
|---|
| 232 | // Returns true if the input made sence, false otherwise. |
|---|
| 233 | private boolean ParseNMEASentence(String s, NMEAParserState ps) { |
|---|
| 234 | try { |
|---|
| 235 | if (s.equals("")) |
|---|
| 236 | throw new NullPointerException(); |
|---|
| 237 | |
|---|
| 238 | // checksum check: |
|---|
| 239 | // the bytes between the $ and the * are xored; |
|---|
| 240 | // if there is no * or other meanities it will throw |
|---|
| 241 | // and result in a malformed packet. |
|---|
| 242 | String[] chkstrings = s.split("\\*"); |
|---|
| 243 | if(chkstrings.length > 1) |
|---|
| 244 | { |
|---|
| 245 | byte[] chb = chkstrings[0].getBytes(); |
|---|
| 246 | int chk=0; |
|---|
| 247 | for(int i = 1; i < chb.length; i++) { |
|---|
| 248 | chk ^= chb[i]; |
|---|
| 249 | } |
|---|
| 250 | if(Integer.parseInt(chkstrings[1].substring(0,2),16) != chk) { |
|---|
| 251 | //System.out.println("Checksum error"); |
|---|
| 252 | ps.checksum_errors++; |
|---|
| 253 | ps.p_Wp=null; |
|---|
| 254 | return false; |
|---|
| 255 | } |
|---|
| 256 | } else { |
|---|
| 257 | ps.no_checksum++; |
|---|
| 258 | } |
|---|
| 259 | // now for the content |
|---|
| 260 | String[] e = chkstrings[0].split(","); |
|---|
| 261 | String accu; |
|---|
| 262 | |
|---|
| 263 | WayPoint currentwp = ps.p_Wp; |
|---|
| 264 | String currentDate = ps.p_Date; |
|---|
| 265 | |
|---|
| 266 | // handle the packet content |
|---|
| 267 | if(e[0].equals("$GPGGA") || e[0].equals("$GNGGA")) { |
|---|
| 268 | // Position |
|---|
| 269 | LatLon latLon = parseLatLon( |
|---|
| 270 | e[GPGGA.LATITUDE_NAME.position], |
|---|
| 271 | e[GPGGA.LONGITUDE_NAME.position], |
|---|
| 272 | e[GPGGA.LATITUDE.position], |
|---|
| 273 | e[GPGGA.LONGITUDE.position] |
|---|
| 274 | ); |
|---|
| 275 | if(latLon==null) |
|---|
| 276 | throw new NullPointerException(); // malformed |
|---|
| 277 | |
|---|
| 278 | if((latLon.lat()==0.0) && (latLon.lon()==0.0)) { |
|---|
| 279 | ps.zero_coord++; |
|---|
| 280 | return false; |
|---|
| 281 | } |
|---|
| 282 | |
|---|
| 283 | // time |
|---|
| 284 | accu = e[GPGGA.TIME.position]; |
|---|
| 285 | Date d = readTime(currentDate+accu); |
|---|
| 286 | |
|---|
| 287 | if((ps.p_Time==null) || (currentwp==null) || !ps.p_Time.equals(accu)) { |
|---|
| 288 | // this node is newer than the previous, create a new waypoint. |
|---|
| 289 | // no matter if previous WayPoint was null, we got something |
|---|
| 290 | // better now. |
|---|
| 291 | ps.p_Time=accu; |
|---|
| 292 | currentwp = new WayPoint(latLon); |
|---|
| 293 | } |
|---|
| 294 | if(!currentwp.attr.containsKey("time")) { |
|---|
| 295 | // As this sentence has no complete time only use it |
|---|
| 296 | // if there is no time so far |
|---|
| 297 | currentwp.attr.put("time", DateUtils.fromDate(d)); |
|---|
| 298 | } |
|---|
| 299 | // elevation |
|---|
| 300 | accu=e[GPGGA.HEIGHT_UNTIS.position]; |
|---|
| 301 | if(accu.equals("M")) { |
|---|
| 302 | // Ignore heights that are not in meters for now |
|---|
| 303 | accu=e[GPGGA.HEIGHT.position]; |
|---|
| 304 | if(!accu.equals("")) { |
|---|
| 305 | Double.parseDouble(accu); |
|---|
| 306 | // if it throws it's malformed; this should only happen if the |
|---|
| 307 | // device sends nonstandard data. |
|---|
| 308 | if(!accu.equals("")) { |
|---|
| 309 | currentwp.attr.put("ele", accu); |
|---|
| 310 | } |
|---|
| 311 | } |
|---|
| 312 | } |
|---|
| 313 | // number of sattelites |
|---|
| 314 | accu=e[GPGGA.SATELLITE_COUNT.position]; |
|---|
| 315 | int sat = 0; |
|---|
| 316 | if(!accu.equals("")) { |
|---|
| 317 | sat = Integer.parseInt(accu); |
|---|
| 318 | currentwp.attr.put("sat", accu); |
|---|
| 319 | } |
|---|
| 320 | // h-dilution |
|---|
| 321 | accu=e[GPGGA.HDOP.position]; |
|---|
| 322 | if(!accu.equals("")) { |
|---|
| 323 | currentwp.attr.put("hdop", Float.parseFloat(accu)); |
|---|
| 324 | } |
|---|
| 325 | // fix |
|---|
| 326 | accu=e[GPGGA.QUALITY.position]; |
|---|
| 327 | if(!accu.equals("")) { |
|---|
| 328 | int fixtype = Integer.parseInt(accu); |
|---|
| 329 | switch(fixtype) { |
|---|
| 330 | case 0: |
|---|
| 331 | currentwp.attr.put("fix", "none"); |
|---|
| 332 | break; |
|---|
| 333 | case 1: |
|---|
| 334 | if(sat < 4) { |
|---|
| 335 | currentwp.attr.put("fix", "2d"); |
|---|
| 336 | } else { |
|---|
| 337 | currentwp.attr.put("fix", "3d"); |
|---|
| 338 | } |
|---|
| 339 | break; |
|---|
| 340 | case 2: |
|---|
| 341 | currentwp.attr.put("fix", "dgps"); |
|---|
| 342 | break; |
|---|
| 343 | default: |
|---|
| 344 | break; |
|---|
| 345 | } |
|---|
| 346 | } |
|---|
| 347 | } else if(e[0].equals("$GPVTG") || e[0].equals("$GNVTG")) { |
|---|
| 348 | // COURSE |
|---|
| 349 | accu = e[GPVTG.COURSE_REF.position]; |
|---|
| 350 | if(accu.equals("T")) { |
|---|
| 351 | // other values than (T)rue are ignored |
|---|
| 352 | accu = e[GPVTG.COURSE.position]; |
|---|
| 353 | if(!accu.equals("")) { |
|---|
| 354 | Double.parseDouble(accu); |
|---|
| 355 | currentwp.attr.put("course", accu); |
|---|
| 356 | } |
|---|
| 357 | } |
|---|
| 358 | // SPEED |
|---|
| 359 | accu = e[GPVTG.SPEED_KMH_UNIT.position]; |
|---|
| 360 | if(accu.startsWith("K")) { |
|---|
| 361 | accu = e[GPVTG.SPEED_KMH.position]; |
|---|
| 362 | if(!accu.equals("")) { |
|---|
| 363 | double speed = Double.parseDouble(accu); |
|---|
| 364 | speed /= 3.6; // speed in m/s |
|---|
| 365 | currentwp.attr.put("speed", Double.toString(speed)); |
|---|
| 366 | } |
|---|
| 367 | } |
|---|
| 368 | } else if(e[0].equals("$GPGSA") || e[0].equals("$GNGSA")) { |
|---|
| 369 | // vdop |
|---|
| 370 | accu=e[GPGSA.VDOP.position]; |
|---|
| 371 | if(!accu.equals("")) { |
|---|
| 372 | currentwp.attr.put("vdop", Float.parseFloat(accu)); |
|---|
| 373 | } |
|---|
| 374 | // hdop |
|---|
| 375 | accu=e[GPGSA.HDOP.position]; |
|---|
| 376 | if(!accu.equals("")) { |
|---|
| 377 | currentwp.attr.put("hdop", Float.parseFloat(accu)); |
|---|
| 378 | } |
|---|
| 379 | // pdop |
|---|
| 380 | accu=e[GPGSA.PDOP.position]; |
|---|
| 381 | if(!accu.equals("")) { |
|---|
| 382 | currentwp.attr.put("pdop", Float.parseFloat(accu)); |
|---|
| 383 | } |
|---|
| 384 | } |
|---|
| 385 | else if(e[0].equals("$GPRMC") || e[0].equals("$GNRMC")) { |
|---|
| 386 | // coordinates |
|---|
| 387 | LatLon latLon = parseLatLon( |
|---|
| 388 | e[GPRMC.WIDTH_NORTH_NAME.position], |
|---|
| 389 | e[GPRMC.LENGTH_EAST_NAME.position], |
|---|
| 390 | e[GPRMC.WIDTH_NORTH.position], |
|---|
| 391 | e[GPRMC.LENGTH_EAST.position] |
|---|
| 392 | ); |
|---|
| 393 | if((latLon.lat()==0.0) && (latLon.lon()==0.0)) { |
|---|
| 394 | ps.zero_coord++; |
|---|
| 395 | return false; |
|---|
| 396 | } |
|---|
| 397 | // time |
|---|
| 398 | currentDate = e[GPRMC.DATE.position]; |
|---|
| 399 | String time = e[GPRMC.TIME.position]; |
|---|
| 400 | |
|---|
| 401 | Date d = readTime(currentDate+time); |
|---|
| 402 | |
|---|
| 403 | if((ps.p_Time==null) || (currentwp==null) || !ps.p_Time.equals(time)) { |
|---|
| 404 | // this node is newer than the previous, create a new waypoint. |
|---|
| 405 | ps.p_Time=time; |
|---|
| 406 | currentwp = new WayPoint(latLon); |
|---|
| 407 | } |
|---|
| 408 | // time: this sentence has complete time so always use it. |
|---|
| 409 | currentwp.attr.put("time", DateUtils.fromDate(d)); |
|---|
| 410 | // speed |
|---|
| 411 | accu = e[GPRMC.SPEED.position]; |
|---|
| 412 | if(!accu.equals("") && !currentwp.attr.containsKey("speed")) { |
|---|
| 413 | double speed = Double.parseDouble(accu); |
|---|
| 414 | speed *= 0.514444444; // to m/s |
|---|
| 415 | currentwp.attr.put("speed", Double.toString(speed)); |
|---|
| 416 | } |
|---|
| 417 | // course |
|---|
| 418 | accu = e[GPRMC.COURSE.position]; |
|---|
| 419 | if(!accu.equals("") && !currentwp.attr.containsKey("course")) { |
|---|
| 420 | Double.parseDouble(accu); |
|---|
| 421 | currentwp.attr.put("course", accu); |
|---|
| 422 | } |
|---|
| 423 | |
|---|
| 424 | // TODO fix? |
|---|
| 425 | // * Mode (A = autonom; D = differential; E = estimated; N = not valid; S |
|---|
| 426 | // * = simulated) |
|---|
| 427 | // * |
|---|
| 428 | // * @since NMEA 2.3 |
|---|
| 429 | // |
|---|
| 430 | //MODE(12); |
|---|
| 431 | } else { |
|---|
| 432 | ps.unknown++; |
|---|
| 433 | return false; |
|---|
| 434 | } |
|---|
| 435 | ps.p_Date = currentDate; |
|---|
| 436 | if(ps.p_Wp != currentwp) { |
|---|
| 437 | if(ps.p_Wp!=null) { |
|---|
| 438 | ps.p_Wp.setTime(); |
|---|
| 439 | } |
|---|
| 440 | ps.p_Wp = currentwp; |
|---|
| 441 | ps.waypoints.add(currentwp); |
|---|
| 442 | ps.success++; |
|---|
| 443 | return true; |
|---|
| 444 | } |
|---|
| 445 | return true; |
|---|
| 446 | |
|---|
| 447 | } catch(RuntimeException x) { |
|---|
| 448 | // out of bounds and such |
|---|
| 449 | // x.printStackTrace(); |
|---|
| 450 | // System.out.println("Malformed line: "+s.toString().trim()); |
|---|
| 451 | ps.malformed++; |
|---|
| 452 | ps.p_Wp=null; |
|---|
| 453 | return false; |
|---|
| 454 | } |
|---|
| 455 | } |
|---|
| 456 | |
|---|
| 457 | private LatLon parseLatLon(String ns, String ew, String dlat, String dlon) |
|---|
| 458 | throws NumberFormatException { |
|---|
| 459 | String widthNorth = dlat.trim(); |
|---|
| 460 | String lengthEast = dlon.trim(); |
|---|
| 461 | |
|---|
| 462 | // return a zero latlon instead of null so it is logged as zero coordinate |
|---|
| 463 | // instead of malformed sentence |
|---|
| 464 | if(widthNorth.equals("")&&lengthEast.equals("")) return new LatLon(0.0,0.0); |
|---|
| 465 | |
|---|
| 466 | // The format is xxDDLL.LLLL |
|---|
| 467 | // xx optional whitespace |
|---|
| 468 | // DD (int) degres |
|---|
| 469 | // LL.LLLL (double) latidude |
|---|
| 470 | int latdegsep = widthNorth.indexOf('.') - 2; |
|---|
| 471 | if (latdegsep < 0) return null; |
|---|
| 472 | |
|---|
| 473 | int latdeg = Integer.parseInt(widthNorth.substring(0, latdegsep)); |
|---|
| 474 | double latmin = Double.parseDouble(widthNorth.substring(latdegsep)); |
|---|
| 475 | if(latdeg < 0) { |
|---|
| 476 | latmin *= -1.0; |
|---|
| 477 | } |
|---|
| 478 | double lat = latdeg + latmin / 60; |
|---|
| 479 | if ("S".equals(ns)) { |
|---|
| 480 | lat = -lat; |
|---|
| 481 | } |
|---|
| 482 | |
|---|
| 483 | int londegsep = lengthEast.indexOf('.') - 2; |
|---|
| 484 | if (londegsep < 0) return null; |
|---|
| 485 | |
|---|
| 486 | int londeg = Integer.parseInt(lengthEast.substring(0, londegsep)); |
|---|
| 487 | double lonmin = Double.parseDouble(lengthEast.substring(londegsep)); |
|---|
| 488 | if(londeg < 0) { |
|---|
| 489 | lonmin *= -1.0; |
|---|
| 490 | } |
|---|
| 491 | double lon = londeg + lonmin / 60; |
|---|
| 492 | if ("W".equals(ew)) { |
|---|
| 493 | lon = -lon; |
|---|
| 494 | } |
|---|
| 495 | return new LatLon(lat, lon); |
|---|
| 496 | } |
|---|
| 497 | } |
|---|