有没有办法使用Android模拟器和“地理定位”来传递当前速度数据以及纬度和经度？

Question

I'm currently building an Android app that uses the Android emulator to pass GPS location data, specifically the latitude , longitude , and speed . I have used a real device and everything is okay, but I now need to do so using only an emulator.

The getSpeed method of the Location class is used to get the speed information. The speed is reported in meters/second. The Location class also provides latitude and longitude using getLatitude and getLongitude , respectively.

Using geo fix longitude latitude when "telnet"-ing into the emulator only allows you to pass latitude and longitude as parameters in the following format geo fix <longitude> <latitude> .

If I were to pass speed from the command line is there a way to do this? I have already read into using the Ripple extention for the Chrome browser.

Thank you.

Answer 1

Regarding the units... Beware! On my Android 2.2 phone, Location.getSpeed() returns the speed in KNOTS , not m/s as stated in the Android developer documentation :(

There are a couple of other posts on the Net about this.

In my Android app, I have a class to record NMEA data to a file.

package log.nmea;

import android.location.GpsStatus;
import android.location.LocationManager;
import android.os.Environment;
import android.util.Log;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.Pattern;

/**
 * NMEA logging... just write NMEA stuff to file on SD card
 *
 * @author Frank van der Hulst
 */
public class NmeaLog {

  private static BufferedWriter logWriter = null;
  private static FileWriter fstream = null;
  private static File logFile;
  private static LocationManager locationManager = null;
  // Default pattern is to log any message starting with $GP
  private static final Pattern pattern = Pattern.compile("^$GP\\w+,");
  private static final String LOGNAME = "NmeaLog";
  private static GpsStatus.NmeaListener nmeaListener = new GpsStatus.NmeaListener() {
    public void onNmeaReceived(long timestamp, String nmea) {
      Log.d(LOGNAME, "onNmeaReceived(" + nmea + ")");
      if (logWriter == null)
        return;
      if (!pattern.matcher(nmea).matches())
        return;
      Log.d(LOGNAME, "onNmeaReceived appending");
      try {
        logWriter.append(timestamp + "," + nmea);
      } catch (IOException ex) {
        Log.e(LOGNAME, ex.getMessage());
      }
    }
  };

  /**
   * Initialise NMEA log file & open for writing
   *
   * @param filepath
   * @param append
   * @param lm
   */
  public static void open(String filepath, boolean append, LocationManager lm) {
    if (logWriter != null)
      return;          // Already open

    // Check SD card is available
    String SDCardStatus = Environment.getExternalStorageState();
    if (!SDCardStatus.equals(Environment.MEDIA_MOUNTED)) {
      Log.e(LOGNAME, "SD card error: " + SDCardStatus);
      return;
    }
    // SD card is OK... try to create/open file
    logFile = new File(filepath);
    if (logFile == null || logFile.isDirectory()) {
      Log.e(LOGNAME, filepath + " cannot be opened");
      return;
    }

    locationManager = lm;
    if (!locationManager.addNmeaListener(nmeaListener)) {
      Log.e(LOGNAME, "Failed to add NMEA listener");
      return;
    }
    Log.d(LOGNAME, "opening " + filepath);
    try {
      fstream = new FileWriter(logFile, append);
      logWriter = new BufferedWriter(fstream, 1024);
    } catch (Exception ex) {
      Log.e(LOGNAME, "Open failed: " + ex.getMessage());
      return;
    }
    Log.d(LOGNAME, "NMEA listener added successfully");
  }

  /**
   * Close log file. The file can be reopened, so don't null locationManager
   */
  public static void close() {
    Log.d(LOGNAME, "close()");
    try {
      locationManager.removeNmeaListener(nmeaListener);
      logWriter.close();
    } catch (Exception ex) {
      Log.e(LOGNAME, "Close error: " + ex.getMessage());
    }
    logWriter = null;
  }
}

Below is a regular Java class which plays these files to the emulator. Very useful when debugging GPS apps.

  package sendgps;

  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.net.Socket;
  import java.net.UnknownHostException;
  import java.util.Date;
  import util.Log;
  import util.OSSpecific;
  import util.Util;

  /**
   *
   * @author Frank van der Hulst
   */
  public class SendGPS {

      private static Socket socket;
      private static OutputStreamWriter w;
      private static BufferedReader r;
      private static final String NMEA_dir = "/home/frank/NetBeansProjects/SendGPS/";

    @SuppressWarnings("UseOfSystemOutOrSystemErr")
      private static void write(String s) throws IOException, InterruptedException {
  //        System.out.println("writing '" + s + "'");
          w.append(s).append("\r\n");
          w.flush();
          String result = r.readLine();
          if (!result.equals("OK")) {
              System.out.println(s + " -> " + result);
          }
      }

    @SuppressWarnings("UseOfSystemOutOrSystemErr")
      private static void read() throws IOException {
          while (r.ready()) {
              System.out.print((char) r.read());
          }

      }

    @SuppressWarnings({"SleepWhileInLoop", "UseOfSystemOutOrSystemErr", "deprecation"})
      public static void main(String[] args) throws UnknownHostException, IOException, InterruptedException {
          socket = new Socket("localhost", 5554);
          final String filename = NMEA_dir + "nmea.log";
          socket.setKeepAlive(true);
          r = new BufferedReader(new InputStreamReader(socket.getInputStream()));
          w = new OutputStreamWriter(socket.getOutputStream());
          Thread.sleep(100);
          read();          // Remove initial prompt

          String[] lines = Util.getFileContents(filename);
          long prevTimestamp = 0;
          for (int line_num = 0; line_num < lines.length; line_num++) {
              String[] parts = lines[line_num].split(",", 2); // Separate timestamp from NMEA string
              if (parts[1].isEmpty()) {
                  continue;
              }
              long timestamp = Long.parseLong(parts[0]);
  //            System.out.println(timestamp + ", "+ prevTimestamp);
              if (timestamp != prevTimestamp) {
                  if (prevTimestamp != 0) {
                      int interval = (int) (timestamp - prevTimestamp);
   //                   interval /= 10;
  //                    System.out.print("Sleep: " + interval);
                      if (interval > 50) {
                          Thread.sleep(interval - 50);
                      }
                  }
                  prevTimestamp = timestamp;
              }
              if (parts[1].startsWith("$GPGGA") || parts[1].startsWith("$GPRMC")) {
                  // Replace hhmmss.ss timestamp at field 1 with current time
                  Date now = new Date();
                  String[] data = parts[1].split(",", 3);
                  parts[1] = data[0] + "," + now.getHours() + "" + now.getMinutes() + "" + now.getSeconds() + "," + data[2];
              }
              write("geo nmea " + parts[1]);
              System.out.println(parts[1]);
          }
          socket.close();
      }
  }

Answer 2

You have to use the geo nmea command via telnet:

geo nmea $GPRMC,081836,A,3751.65,S,14507.36,E,000.0,360.0,130998,011.3,E*62

The definition of the format is here . In this example, 000.0 is the ground speed in knots.