将信息从Android发布到PHP服务器

所以我正在编写一个Android应用程序，其中一部分应该使用GPS来获取经度/纬度。这些值应该发布到我也正在运行的PHP服务器。我发布的功能如下：

public void doAll() {
Double locLat, locLon;
    try {
    locLat = locManager.getLastKnownLocation(locProvider).getLatitude();
    locLon = locManager.getLastKnownLocation(locProvider).getLongitude();
    } catch (NullPointerException e) {
    locLat = -1.0;
    locLon = -1.0;
    }
try {
    HttpClient client = new DefaultHttpClient();
    //we put all the parameters in the URL itself
    HttpPost request = new HttpPost("http://fatalatour.com/database.php?function=get_all&latitude="+Double.toString(locLat)+"&longitude="+Double.toString(locLon));
    ResponseHandler <String> responseHandler = new BasicResponseHandler();
   //List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
   //nameValuePairs.add(new BasicNameValuePair("latitude", Double.toString(locLat)));
   //nameValuePairs.add(new BasicNameValuePair("longitude", Double.toString(locLon)));
   //request.setEntity(new UrlEncodedFormEntity(nameValuePairs));
   String response = client.execute(request, responseHandler);
   Log.i("HOMI_RESPONSE", response.toString());

}

还有其他代码，但我相信这就是实际影响 locLat 和 locLon 发布的全部内容。

对于服务器端，我有：

function get_all() {
            $lat = trim($_GET['latitude']);
            $lon = trim($_GET['longitude']);
            // DEBUG
            $f = fopen('debug.log', 'a');
            fprintf($f, 'get_all: '.print_r($_REQUEST, true)."'n");
            $result = mysql_query("SELECT * FROM homi_table");
            $num = 0; //# of homicides
            while ($row = mysql_fetch_assoc($result)) {
                    $d = distance($row['latitude'], $row['longitude'], $lat, $lon, "K");
                    if ($d < 100) { //number to change for distance filter
                            $num += 1;
        echo "fatality:".$row['slug']."~".strtoupper($row['name']).", Age ".$row['age']."'n".$row['date']."'nhttp://projects.latimes.com/homicide/post/".$row['slug']."~".$row['latitude']."~".$row['longitude'];

                            // GH: limiting the number of results to 100
                            if ($num == 100) {
                                    break;
                            }
                    }
            };
            echo $num;
            fprintf($f, "get_all: returning: ".$num."'n");
    }

现在的问题似乎是如何处理$lat和$lon。当我为 PHP 中的每个应用程序硬编码静态数字时，该应用程序可以工作，但是当我将其保留为变量（应该是）时，它会失败。任何帮助将不胜感激！