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-rw-r--r--src/main/java/org/traccar/helper/NMEA.java126
1 files changed, 126 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/helper/NMEA.java b/src/main/java/org/traccar/helper/NMEA.java
new file mode 100644
index 000000000..cae47a8f6
--- /dev/null
+++ b/src/main/java/org/traccar/helper/NMEA.java
@@ -0,0 +1,126 @@
+package org.traccar.helper;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+public class NMEA {
+
+ // fucking java interfaces
+ interface SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position);
+ }
+
+ // utils
+ static float Latitude2Decimal(String lat, String NS) {
+ float med = Float.parseFloat(lat.substring(2)) / 60.0f;
+ med += Float.parseFloat(lat.substring(0, 2));
+ if (NS.startsWith("S")) {
+ med = -med;
+ }
+ return med;
+ }
+
+ static float Longitude2Decimal(String lon, String WE) {
+ float med = Float.parseFloat(lon.substring(3)) / 60.0f;
+ med += Float.parseFloat(lon.substring(0, 3));
+ if (WE.startsWith("W")) {
+ med = -med;
+ }
+ return med;
+ }
+
+ // parsers
+ class GPGGA implements SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position) {
+ position.time = Float.parseFloat(tokens[1]);
+ position.lat = Latitude2Decimal(tokens[2], tokens[3]);
+ position.lon = Longitude2Decimal(tokens[4], tokens[5]);
+ position.quality = Integer.parseInt(tokens[6]);
+ position.altitude = Float.parseFloat(tokens[9]);
+ return true;
+ }
+ }
+
+ class GPGGL implements SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position) {
+ position.lat = Latitude2Decimal(tokens[1], tokens[2]);
+ position.lon = Longitude2Decimal(tokens[3], tokens[4]);
+ position.time = Float.parseFloat(tokens[5]);
+ return true;
+ }
+ }
+
+ class GPRMC implements SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position) {
+ position.time = Float.parseFloat(tokens[1]);
+ position.lat = Latitude2Decimal(tokens[3], tokens[4]);
+ position.lon = Longitude2Decimal(tokens[5], tokens[6]);
+ position.velocity = Float.parseFloat(tokens[7]);
+ position.dir = Float.parseFloat(tokens[8]);
+ return true;
+ }
+ }
+
+ class GPVTG implements SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position) {
+ position.dir = Float.parseFloat(tokens[3]);
+ return true;
+ }
+ }
+
+ class GPRMZ implements SentenceParser {
+ public boolean parse(String[] tokens, GPSPosition position) {
+ position.altitude = Float.parseFloat(tokens[1]);
+ return true;
+ }
+ }
+
+ public class GPSPosition {
+ public float time = 0.0f;
+ public float lat = 0.0f;
+ public float lon = 0.0f;
+ public boolean fixed = false;
+ public int quality = 0;
+ public float dir = 0.0f;
+ public float altitude = 0.0f;
+ public float velocity = 0.0f;
+
+ public void updatefix() {
+ fixed = quality > 0;
+ }
+
+ public String toString() {
+ return String.format("POSITION: lat: %f, lon: %f, time: %f, Q: %d, dir: %f, alt: %f, vel: %f", lat, lon, time, quality, dir, altitude, velocity);
+ }
+ }
+
+ GPSPosition position = new GPSPosition();
+
+ private static final Map<String, SentenceParser> sentenceParsers = new HashMap<String, SentenceParser>();
+
+ public NMEA() {
+ sentenceParsers.put("GPGGA", new GPGGA());
+ sentenceParsers.put("GPGGL", new GPGGL());
+ sentenceParsers.put("GPRMC", new GPRMC());
+ sentenceParsers.put("GPRMZ", new GPRMZ());
+ //only really good GPS devices have this sentence but ...
+ sentenceParsers.put("GPVTG", new GPVTG());
+ }
+
+ public GPSPosition parse(String line) {
+
+ if (line.startsWith("$")) {
+ String nmea = line.substring(1);
+ String[] tokens = nmea.split(",");
+ String type = tokens[0];
+ //TODO check crc
+ if (sentenceParsers.containsKey(type)) {
+ sentenceParsers.get(type).parse(tokens, position);
+ }
+ position.updatefix();
+ }
+
+ return position;
+ }
+}