I am interested in making android app like crickbuzz that will fetch live content from server and also there is option of like and comment for users for feedback. So, can anyone tell that how to implement this i.e (how to fetch data from server) how that data will fit in app(confused about this how data get fit in instagram app means profile, home, search tab)
thanks
I suggest you check out this links
Android, PHP & MySQL
Fetch Data From Server
Ok, let's break it down:
The data is obtained from the server using http requests. It is usually received in the form of JSON String, basically a ordered, human-readable data format which is easy to read and parse.
On the app side, you need to implement the layout, which is done in xml and Java. You also need some logic which will obtain the data with the aforementioned requests, parse it, turn into Java Objects and put everything into the layout.
The process is not really complex, could be completed by a single person, but you will need experience, time and good architectural decisions.
If this is your first time with Android app programming, do some tutorials (especially ones that cover networking), learn some libraries (Volley, Retrofit, org.json, RXJava, Picasso will be really useful for what you ask about) and code several small apps from start to end. After that you may be ready to tackle the app you described :-)
Related
first post.
I am building an android app and the backend (remote server) im using ktor with exposed and hitting a postgresql data base. I am just unsure upon getting my results back from queries how I should attempt to send those back to my user app on android. What would be the right way. To have the user app install exposed library and just send the query results ? format all the results to a json string and blast that? Just dont know what would be ideal.
I haven't really attempted anything yet because I was looking for a "best practices" idea.
Hi and welcome to Stackoverflow.
There is no one "best practice" way to send the data from the server to the client. Noramlly it depends on your use case. However, one common way that I would suggest you use is to create RESTful-API.
This means:
Requests and Responses to/from the server will be serialized to JSON.
Confirm to HTTP verbs semantics (use GET to read data, PUT to update, etc).
Use status code for error handling
Follow the REST API guidelines for best practices (API versioning, end point names, pagination, etc)
To read more about REST API guidelines, this page is useful.
For Ktor, this will mean having a serializer, and then defining your routes. This guide is useful for Ktor.
Although this is not the only way, but it will provide you with enough experience to explore others APIs (Custom API, RPC, SOAP, etc).
I have a new project involving the build of an Android app for a website of a hiking club. The website has a login functionality after which the user can browse through available hikes, subscribe to a hike, view the other subscribers, contact the organizer etc.
The original site is based on a MySQL database with a front end of .asp pages. Most data is passed through the pages as GET parameters on the query string.
New to Android development, some things really puzzle me, even after reading several tutorials. I am thinking towards an architecture baes on REST webservices but there a several obstacles to overcome and chooses to be made.
Apart from using REST, some other options are available:
Call the original .asp pages from the app instead of building a dedicated Web service. This leaves me with much less code to write, the original business logic (queries e.a.) as well as the login system can be used (with the "remember me" functionality based on cookies). Downside is that the (X)HTML code in the response needs to be parsed to show in the app GUI, where the majority of the response code is useless ballast code. Also, it does not feel very good from an archtitectorial point of view.
Using a SOAP based webservice. I am totally unfamiliar with SOAP and it appears to be much too heavyweight for a mobile device.
Using REST services. I am leaning towards this option, and have made
some already working services using the SLIM framework. But there
are some problems. First, REST is stateless by definition and does
not seem to support sessions. But the "Remember me" option is
required for the app after login in for the first time, the user
needs not to login again unless he explicitly logs out.
But how can we achieve that?
First option is to designing some completely client-site login/logout system which saves the credentials locally until the user logs out. And sending the credentials with each request to the Web service as POST parameters, or somehow in the HTTP Authorization request header, though I am not familiar with that.
Second option is to deviate a bit from RESt principles and use a session mechanism anyway. After sending the credentials to the web service, a cookie is created and send to the client app. The dartabase cannot be extended so there is no option to save a token in the user table. Maybe the usernae/password can be encrypted and send as a cookie to the app, and decrypted at each subsequent request?
I am a bit lost in this, and look forward to serious suggestions!
I believe that from a long term perspective, it is important that you lean towards REST Interfaces. While JSoup and/or WebView approaches will definitely work, it is important to have the flexibility to redefine/design the mobile application in ways that are completely agnostic of the Server side. REST will help you there and you do not need to play catch up with the Server side, everytime they change the HTML pages, etc.
Going REST will also help in future with writing additional mobile applications and even on different platforms like iOS, if your roadmap contains that.
You can use jsoup to parse the html pages from your Android app and reorganize the information of the web page, this option will gives you ability to quickly develop an App, later you may think on add REST interfaces to your web site and populate data in json.
You can also use WebView to laod your web pages if you don't want to parse html pages.
I suggest you using REST architecture as you said. You can use a rest client library for Android as RESTDroid, take a look to the guide because there is a implementation example with special header needed for the particular web service used (Parse.com in this case).
I have a database and I need to present a data via HTTP using JSON web services. Currently, I'm designing JSON datasets that will be provided as web services. The data from the tables will be aggregated to suite an app needs.
If the data size is large and we will try to download that at once then it might take too much time and an app will not be responsive at start. That's bad. It's well known we should minimize the number of http requests the app will make to download the data. However if we would split the data into small chunks then during every app action step an app will performe http requests and that might be unresponsive solution too.
We are talking here about mobile app development, so internet will be exposed over cellular ISP or wifi, so the speed might be quite slow. I understand the split process depends on app workflow process and etc., just curious are there any general guidelines? For example: if JSON data is larger than 1MB then definitely split it into smaller chunks...
Look at how your mail read work. You probably have tens of thousands of emails in your account. The app will show the first ones then provide a button at the bottom of the list to display more items. It's a pretty good solution usually to provide a lot of data.
Also #Selvin ideas are just great. Don't use UI thread to download stuff, use a different thread. Services are pretty good for getting data asynchronously.
One of the way is to create a service which gets started when there is network. All downloaded data can be cached in sqlite and use a content provider to get the data. But it depends on your app.
Sometimes it depends on your UI Screen. For eg. You can create a Listview with load more. On click of it load extra data.
Other way is to create API such as which gives only updates based on timestamp. But its all depends on the app. Just sharing my ideas. Might not be perfect. Others can surely give a better one.
I am supervising a project done by two students that involves retrieving information from a server and displaying it on an android phone. The students have never learnt networking, sql or java before (although they do know how to program) and are only now learning how to setup socketed connections between the phone and a sample server app that i gave them.
They will need to setup a simple sql database on the server on the campus network and be able to communicate with it and only pull information from the database and display it on the phone.
My current plan is that they will receive xml objects generated on the server side sent as a stream through the socket connection. They will then be able to generate a DOM using javax.xml classes and display it as they see fit on the phone itself.
Is this a valid method? What kind of problems can they expect to experience by following this technique? Is there another/better/correct way to do this (without using php or webservices)? The system will be for multiple users so will there be any significant performance issue with the proposed method?
Note 1: The phone never sends any request other than a single multicharacter identifier. The server interprets this identifier and returns information from preprogrammed queries and places it into an xml format.
Webservices sound like the correct approach for this, since you would not want to directly allow communication to the database over the internet.
The book "Unlocking Android" from Manning Publications, ISBN 978-1-933988-67-2 has a Chapter (6) dedicated to "Networking and web services".
Ah and then there is the one and only very nice video from a presentation regarding Android and RESTful webservices from the Google IO.
Couchbase, although from the NoSQL movement have a nice summary as well.
You could use JSON instead of XML, could be easier to parse and work with (feels more lightweight to me at least).
Sorry, forgot the answer for your search of problems:
Activity freezing upon freezing requests: Use additional threads for your requests
How to generally handle high latency
Handle offline behaviour
I'm writing an app that will periodically send information out to a remote server, and then get relevant information about other users from that server back to the local database. What's the best way to handle sending out this info (i.e.: XML or binary) and writing it to the remote server.
Also, how can I assure that, when 500+ users' data get's to the server or FTP (or better alternative?) at once, the appropriate fields gets overwritten or added, without skipping any or overwriting the entire thing? Thanks for the help.
i was looking for that answer too and i found some nice tutorials. Unfortenly they are not in english, but you can understand a princip.
This (http://vimeo.com/29332913) is the forth video of tutorials. Just click on authors name and start 3 tutorials before.
Hope it will help you XD
Janez
Have you considered JSON? FTP is generally a solution when it comes to binary data (large files, etc.), however I assume you want to exchange data that contains information in a textual format, so for a website HTTP will be a good way (the best way depends entirely on your server setup, your data format and model).
I have to add, that YAML is also a very nice data format tool if you are using Ruby frameworks, which I prefer over JSON (personal experience).