android - How to append items to JSON file without parsing and rewriting -


i generating observation objects , want add them json file. way i'm doing now, i'm parsing existing file , converting json object, adding new observation instance retrieved collection, parsing json , re-writing file.

here's code: 

final file file = getfile(); final observationset observationset = retrievepreviousobservations(file);  observationset.getobservations().add(observation[0]);  final outputstream os = new fileoutputstream(file); os.write(gsonhelper.tojson(observationset).getbytes()); os.close();

...

private observationset retrievepreviousobservations(final file file) {     observationset observationset = new observationset();     try {         final bufferedreader br = new bufferedreader(new filereader(file));         observationset = gsonhelper.getgson().fromjson(br, observationset.class);     } catch (filenotfoundexception e) {         log.w(tag, "no previous file found, first entry", e);     }     return observationset; }

the problem is, observation objects quite big , after several tens of entries, appending process takes long time (generally more 10 seconds 20+ items in collection).

is there way append existing json file without having parse existing one, adding object, parsing , rewriting file?


Comments

Post a Comment

Popular posts from this blog

javascript - Using jquery append to add option values into a select element not working -

i'm looking dynamically populate select element names of items stored array. for reason it's not working , i'm not sure why. html: <div class="col-md-4 col-md-offset-4"> <select class="select1"> </select> , <select class="select2"> </select> </div> note i'm using bootstrap layout. here's jquery i'm using try , populate ".select1" jquery: select: function() { $.each(state.greens, function(index, value) { $(".select1").append("<option value =' " + index + " '>" + state.greens[index].name + "</option>"); }); } note function 'select' stored within object called 'display'. state.greens name of array i'm trying access. so @ end of html page call display.select(); call function. no error messages showing in console. also, saw question: appending
Read more

Android soft keyboard reverts to default keyboard on orientation change -

i'm building android soft keyboard , can't seem fix bug - have arabic , qwerty keyboard , when rotate device on qwerty keyboard (or arabic shift), it's if program has "restarted" , becomes arabic keyboard without shift. the onsaveinstancestate(bundle savedinstancestate) not work because application not extend activity inputmethodservice . i put following in android manifest android:configchanges="keyboard|keyboardhidden|orientation" android:windowsoftinputmode="stateunchanged|adjustresize"> i tried using @override public void onconfigurationchanged(configuration newconfig) { super.onconfigurationchanged(newconfig); log.i(mydebug, "config changed " + currentkeyboard.equals(qwerty)); } however, currentkeyboard.equals(qwerty)) results false , made sure true before orientation change. any appreciated. i think applications fault. if application restarting on orientation change
Read more

jquery - javascript onscroll fade same class but with different div -

i new @ javascript , want learn new. there wrong code : why div fades @ same time. i want ask how fade different div s same class name.can me , explain me. thanks in advance. javascript: $(window).scroll(function(){ if ($( "div.fade" ).offset().top - $(window).scrolltop() <= 100){ $('.fade').addclass( "fade-in"); } else { $('.fade').removeclass("fade-in"); } }); here jsfiddle onscroll = function () { var scrolltop = $(this).scrolltop() ; $("div.fade").each(function(){ if(($(this).offset().top - scrolltop) <= 100){ $(this).toggleclass("fade-in"); } }) }
Read more