Android : Reading parameters in file upload in cordova android using php

I am trying to implement file upload/download using this plugin(https://github.com/apache/cordova-plugin-file-transfer/blob/master/doc/index.md).But i am failed to read the parameters(ie filename,mimetype) from the url.Here is the javascript code

//paramters for upload file
    var options = new FileUploadOptions();
             options.fileKey = "file";
             options.fileName = uri.substr(uri.lastIndexOf('/') + 1);
             options.mimeType = "text/plain";

upload url

var ft = new FileTransfer();
         ft.upload(uri, encodeURI('http://192.168.43.211/insiderapp/insiderapp_backend.php?action=uploadfile'), win, fail, options);

win and fail are success and error callback functions actual problem is i can't get options in php file. here is my php

function uploadFile(){
    //get the parameters
    $options=json_decode(file_get_contents('php://input'));
    echo $options->fileKey;
}

It will returns Trying to get property of non-object error.