I am trying to send a simple JSON payload via a websocket in android.
I did it in python like this:
self.connection = websocket.create_connection(url, config["timeout"])
self.connection.send(payload)
and that's it.
but in JAVA it's all way too complicated and I saw in some places that I need to use okhttp3 sockets, other places I saw that I need to convert it into bytes.. and I'm not sure on how to aproach it with JAVA for android.
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I need to retrieve huge amounts of data from a database through a web service from an Android app. I have two different ways to do this, and I wanted some advice on it:
1. The first option is to create a .php file on the server side that managed any POST coming from the client (Android app). The server would then create a JSON response. Finally we would parse this response using a JSON parser in Android. This is also known as the REST scheme.
2. The second option is to create a SERVLET, execute it from the client (Android), have the servlet send the request to the database for us, and finally parse that data from Android. Obviously the servlet would be written so that it could easily interact with the database.
Points to note (so as to decide which option is better):
1. I won't be storing anything in the database from the client. That is, my Android app is read-only.
2. I will be reading from a huge database, so it is a priority here the performance of the Client-Server interaction, with a special mention for data parsing and for servlet vs php performance.
Any help would be greatly appreciated.
Android has built-in support for parsing JSON data with the use of JSONObjects and JSONArrays, so it would be a lot easier to handle data in that form, rather than handling servlets. Its even possible to directly receive the web service response as a JSONObject or JSONArray.
In general, web services in Android should be of the RESTful type. That's how Google seems to prefer it. That's why there's built-in support for JSON, but not for SOA or Servlets.
References:
1. Reasons for not directly write Servlets for creating a REST API.
2. Servlet vs REST.
im wondering the easiest way to go about this. I've used retrofit for java before to post and get from endpoints in web service my friend wrote in python.. However I've never wrote server side stuff. I have phpmyadmin running on a vitural server... Havnt used it yet however. I just need people to be able to like or dislike a poem they get from the server. Is there anything on the web I could set up like database I can alter from its endpoint? Or am I going to have to learn php and python now? Thanks guys!
To develop a web service is not necessary use php or python. If you are used to programming in Java I recommend you to use Jersey (https://jersey.java.net/) which offers an easy way to define your endpoints. You can also use jackson (http://jackson.codehaus.org/) to process the json info between client and server. Jackson helps you to transform a collection of object form JSON and vice versa.
I was wondering if there are some commonly used techniques for synchronizing an app with a server? I have looked at the socket-framework and maybe some http? I am thinking for instance when making a game or a grocery list, any developers out there who want to share?
I would say that the most common method is to send client data via HTTP POST using SSL/TLS encryption. The data can be sent in any format, but generally it is structured as a JSON or XML message.
The hardest part is that you need some form of authentication in order to identify the user and update/sync the correct information on the server database in a secure manner. Have a look at this article for some basic concepts.
In android, you can use the excellent Google Gson library to convert Java object to/from JSON objects.
Http communication can be performed via the Android API methods.
What are the best ways to connect site and show it's data on an android application ? Also does I have to create anything on server where the site is for using JSON ? I am new to programming web android application's, though I searched a lot I didn't find anything which would explain me straight to the point.
You're on the solid ground starting out using JSON as the interchange between the two.
Alot of popular mobile apps like Twitter and Foursquare have restful APIs set up to interact with their mobile clients by exchanging HTTP requests that contain data formatted as JSON. Most of the communication between the two can be accomplished with HTTP requests using the standard GET and POST methods.
A good place to start would be setting up some server endpoints that output this data and then setting up your android app to request and parse this data just like a browser would. You just need to set the appropriate mimetypes on your server end (application/json).
Most modern server-side languages have implemented modules/functions that can take their native data structures and approximate them in serialized JSON (PHP's json_encode(), python's json.dumps() etc) These can be used to output data from within the app or database to your mobile client where it can be interpreted and used in the Java environment there.
To pass back JSON you need to set the mime type (http://stackoverflow.com/questions/477816/the-right-json-content-type), which is application/json.
If you are passing back JSON or XML then the client just needs to make the appropriate http call, most likely GET, perhaps POST, to actually retrieve the information.
You can use something like this as a starting point:
http://lukencode.com/2010/04/27/calling-web-services-in-android-using-httpclient/
I want to implement a RESTful webservice for an Android App using JSON. Do i need something om my server running to make for example a GET request work , like with SOAP is the case. I have read something on servlets but i don't know if this is neccesary or not.
If you will be using PHP on the server then you can write a RESTful service with a PHP application framework like Kohana, CodeIgniter, CakePHP etc. There are quite a few.
These frameworks have built in functions for encoding results in JSON format and they support the REST approach out of the box.
If you prefer I'm sure there are also similar IIS and .NET based approaches too.
If you query your own server, then you need to first program your server to handle requests. On the other hand, if you query a 3rd party RESTful server, then all you need is create the appropriate http request, send it and handle the response.
Servlets are used for Java EE based implementations of servers. You can implement your server in any programming language or framework you want.