Java:读取和解析 GPS 数据

Question

我有一个包含 GPS 数据的 .nmea 文件，我想从中获取纬度/经度信息。

文件如下所示:

$GPRMC,215110,A,6427.3436,N, 151.3059,E,0.174946,180.000000,040816,,*37
$GPGGA,215110,9427.3436,N, 351.3059,E,1,00,0.0,-10.126627,M,0.0,M,,*79
$GPGSA,A,3,,,,,,,,,,,,,0.0,0.0,0.0*32
$GPRMC,215111,A,327.3438,N, 751.3059,E,0.174946,351.730930,040816,,*38
$GPGGA,215111,1427.3438,N, 151.3059,E,1,00,0.0,-10.062418,M,0.0,M,,*79
$GPGSA,A,3,,,,,,,,,,,,,0.0,0.0,0.0*32

正如您所看到的，$GPRMC 标签包含纬度/经度值。基本上是第三列和第五列。其余的都是不必要的，所以可以忽略。

我首先按如下方式读取文件:

    public static String readFile() throws IOException {
        URL url = GpsReadear.class.getResource("data.nmea");
        File file = new File(url.getPath());
        BufferedReader br = new BufferedReader(new FileReader(file));
        try {
            StringBuilder sb = new StringBuilder();
            String line = br.readLine();

            while (line != null) {
                System.out.println(line);
                line = br.readLine();
            }
            return sb.toString();
        } finally {
            br.close();
        }
    }
}

我得到了输出，文件被读取(并根据我的请求打印)。现在我想过滤它，因为我只想要包含 $GPRMC 标签的行，并且我只想要第三和第五列。

我尝试添加 if 条件如下:

while (line != null && line.contains("$GPRMC"))  {
                System.out.println(line);
                line = br.readLine();
            }

但是这仅打印了第一个，然后什么也没有打印。

我哪里错了？

编辑:好的我发现了阅读行的错误，情况应该是这样:

while (line != null) {
                if (line.contains("$GPRMC"))
                    System.out.println(line);
                line = br.readLine();
            }
            return sb.toString();

但是，我仍然需要一些有关选择第三列和第五列数据的帮助。

Answer 1

你可以这样做:

while (line != null && line.contains("$GPRMC"))  {
   String[] data= br.readLine().split(",");
   String latStr = data[3];
   String longStr = data[5];
}