如何从Triptracker android应用程序接收php中的JSON数据？

Question

The app sends gps location to a php server of the user's setting. I have a PHP MySQL model server. I don't know how to receive the JSON that is sent from the app into my server's database. ANy help would be appreciated. Thanks in advance. The code for this is at https://github.com/jcs/triptracker/blob/master/src/org/jcs/triptracker/TrackerService.java

The POSTed parameters are a locations array, each element being a hash including time (a Unix Timestamp from the Location service), latitude and longitude (two float values of arbitrary precision), and speed in meters per second.

Thanks in advance.

Answer 1

You can use json_decode() to create an object out of the json you receive.

An example would be:

$data = json_decode($_POST['yourdata']);

Assuming that the JSON looks something like this:

{"foo":"bar"}

You can now do:

echo $data->foo;

Use this data in your mysql query.

Answer 2

you can get the variables in your php like this:

$lat = $_REQUEST['lat'];
$lng = $_REQUEST['lng'];

Then you can insert that $lat and $lng in your database.

Example:

function launchQuery($call)
{
    $link = mysqli_init();
    if (!$link) {
        die('mysqli_init failed');
    }

    if (!mysqli_options($link, MYSQLI_INIT_COMMAND, 'SET AUTOCOMMIT = 1')) {
        die('Setting MYSQLI_INIT_COMMAND failed');
    }

    if (!mysqli_options($link, MYSQLI_OPT_CONNECT_TIMEOUT, 5)) {
        die('Setting MYSQLI_OPT_CONNECT_TIMEOUT failed');
    }

    if (!mysqli_real_connect($link, $dbhost, $dbuser, $dbpassword, $dbname, $dbport)) {
        die('Connect Error (' . mysqli_connect_errno() . ') '  . mysqli_connect_error());
    }       

    mysqli_query($link,"SET NAMES 'utf8'");
    $rs = mysqli_query($link, $call);

    mysqli_close($link);

    return $rs;
} 

launchQuery("insert into whatever_your_table_name_is (latitude, longitude) values (".$lat.",".$lng.");");

Answer 3

took me a while to decode the format but the following snippet is extracting the data from the App. Note that trip tracker might submit an array of previous location points it couldn't transfer so far.

<?php
$locations  = $_REQUEST['locations'];   // Get all POST arrays

i = 0;                                  // Choose first locations array

// Now you can access single fields with:
time      = $locations[i]['time']; 
latitude  = $locations[i]['latitude'];
longitude = $locations[i]['longitude'];
speed     = $locations[i]['speed'];

?>

Note that 'time' is MILLIseconds since epoch, for unix timestamp we'll need to divide by 1000 into a float to allow conversion. Again, there can be more than 1 locations array available, access the other arrays by counting up i in a loop or so.