In my Android project i use Retrofit 2 with GSON. My problem is inside of JSON I recieve there is an object for example "city":{"id":"1","name":"Washington"} and when user doesn't fill city field server sends me "city":"" (now city is String). So I can't parse this.
You have two options:
Get your backend fixed
Write a custom parser for it
You can register custom parsers with Gson.
Follow the example on the offical site to create one: https://sites.google.com/site/gson/gson-user-guide#TOC-Custom-Serialization-and-Deserialization
Related
I want to display JSON informations in an android app's ListView.
I'm using Django Rest Framework , i already serialized my objects and converted the info to JSON format and are accessible via 127.0.0.1:8000/.
Here are my objects :
you have to use retrofit library with gson library.
Gson: serialization/deserialization library to convert Java Objects into JSON and back
Retrofit: Retrofit turns your HTTP API into a Java interface.
Once you get a hold of the list of object in java you can use a adapter in a list view to display the objects. tutorial
I want to develop an android application which parses json data into some meaningful data sets and accordingly display them into the UI .
I need suggestions on how to go about it.
PS : i have 0 idea of the available options to chose , so different ways to do the same would help me a lot , since i am new to it
Thanks in advance
You can use gson for parsing the data together with some network library like volley or can use retrofit which provide direct parsing with the help of gson and other lib.
To accomplish this you first need to create some relevant Java pojo
For corresponding json dataset , so that you can use it .
You can generate pojo from this website very easily for any json data
http://www.jsonschema2pojo.org/
I need to get some simple data (actual currency values) to my android application. I'm not sure what is the best way to achieve it. Do I have to make some database and put it on server and than update it manually or there is some better way?
You can use an API Service and access to this service from you android device. You donot need to do a server implementation for this.
e.g. for exchange rates check https://openexchangerates.org/
Yes.
Please make a server and a PHP which going to print out the values in JSON. You can validate your json with http://jsonlint.com/. After it you can download and parse the json with yourself or a 3rd part library (like retrofit).
You can use this website to generate POJO, so retrofit can parse the json for you by it`s own.
http://www.jsonschema2pojo.org/
select: JSON instead of scheme and select GSON instead of JSON, if you are using retrofit.
sources:
https://en.wikipedia.org/wiki/Gson
https://github.com/square/retrofit
http://blog.robinchutaux.com/blog/a-smart-way-to-use-retrofit/
I just started using the website http://www.kimonolabs.com and created an API as I need to retrieve data from my school website to put into the school app I am creating. Unfortunately, I do not really plan ahead, and this leads me to my 2 questions:
1) How do I include this API in my school Android App?
2) How do I parse the JSON in this API? (Or just linking me to another page on this would be equally as greatly appreciated :) )
Thanks very much for any help you can give! Sorry for my language, I am 14 :P
First things first. Take a look at AsyncTask in Android. AsyncTask is used to perform operations asynchronously. Take a look at this answer explaining how parameters are passed to AsyncTask.
You can use libraries mentioned bellow to do same thing:
Asynchronous Http Client
Volley
Once you communicate with server and receive response, you have to parse JSON data.
The key you have to remember for this is
[] - square bracket represents JSON Array
{} - curly bracket represents JSON Object
Everything else will be combination of these.
This tutorial will help you regarding JSON parsing.
JSON object to Java object conversion
To convert json data to java object you can use:
Jackson
Gson
Follow this link or this link for nice GSON tutorial.
I personally used GSON, and it is best library for json to java object conversion.
Hello, I am a newbie to android development
I am trying to understand how to parse JSON in android activity
I am not using anything such as PHP etc
I am using NODEJS on server in AWS to generate JSON
I have a JSON ::
{"1":"Hello","2":"World"}
This JSON is coming from an AWS server i have hosted my application
How to parse the JSON data for above JSON ?
How to populate to an android activity ?
PS:: Any links that would help me understand this concept would also be helpful
Thanks,
In the most basic form, you can parse JSON by simply creating a JSON object and passing the string representation of the JSON object to the constructor, like so...
JSONObject myJson = new JSONObject("{\"1\":\"Hello\",\"2\":\"World\"}");
Read the docs on this class for more info on how to extract data from objects and etc... https://developer.android.com/reference/org/json/JSONObject.html
A more abstract way of parsing can be done via the GSON library. In a nutshell, GSON has the ability to take your JSON response and parse it into a Java object for you so that you don't have to do it yourself.
Admittedly using GSON can save a good amount of time from writing code to parse yourself, however, I would probably rather go the JSONObject route if you're new to this.