Sync data between Android App and webserver

Question

I want to sync data  such as db record  media  between an Android App and a Server  If you ve seen Evernote or similar Applications  you certainly understand what I mean   I have some question  imagine we want to sync DB records     Every user has a part of server space for himself  such as Evernote or Dropbox   Maybe the user creates new records by cellphone and creates new records in server  How can I match these records together  If there are records with same ID What algorithms do you suggest me  Except JSON  Are there any way for send data between cellphone device and server  If SyncAdapter and ContentProvider can solve my problems  please explain exactly for me   If you could offer some samples or tutorials to me OR Any advice or keywords to help broaden guide my search would be appreciated as well

User · Answer

For example  you want to sync table todoTable from MySql to Sqlite  First  create one column name version  type INT  in todoTable for both Sqlite and MySql   Second  create a table name database version with one column name currentVersion INT    In MySql  when you add a new item to todoTable or update item  you must upgrade the version of this item by  1 and also upgrade the currentVersion   In Android  when you want to sync  by manual press sync button or a service run with period time     You will send the request with the Sqlite currentVersion  currently it is 1  to server  Then in server  you find what item in MySql have version value greater than Sqlite currentVersion 1  then response to Android  in this example the item 3 with version 2 will response to Android   In SQLite  you will add or update new item to todoTable and upgrade the currentVersion

User · Answer

If we think about today  accepted answer is too old  As we know that we have many new libraries which can help you to make this types of application   You should learn following topics that will helps you surely    SyncAdapter  The sync adapter component in your app encapsulates the code for the tasks that transfer data between the device and a server  Based on the scheduling and triggers you provide in your app  the sync adapter framework runs the code in the sync adapter component  Realm  Realm is a mobile database  a replacement for SQLite  amp  Core Data  Retrofit Type-safe HTTP client for Android and Java by Square  Inc  Must Learn a-smart-way-to-use-retrofit   And your sync logic for database like  How to sync SQLite database on Android phone with MySQL database on server   Best Luck to all new learner

User · Answer

Look at parseplatform org   it s opensource project    As well as you can go for commercial package available at back4app com    It is a very straight forward and user friendly server side database service that gives a great android client side API

User · Answer

I would suggest using a binary webservice protocol similar to Hessian  It works very well and they do have a android implementation  It might be a little heavy but depends on the application you are building  Hope this helps

User · Answer

Grantismo gives a great overview of Android sync components   SyncManagerAndroid library provides a simple 2-way sync implementation to plug into the Android Sync framework  AbstractThreadedSyncAdapter OnPerformSync     https   github com sschendel SyncManagerAndroid

User · Answer

If you write this yourself these are some of the points to keep in mind  Proper authentication between the device and the Sync Server  A sync protocol between the device and the server  It will usually go in 3 phases  authentication  data exchange  status exchange  which operations worked and which failed   Pick your payload format  I suggest SyncML based XML mixed with JSON based format to represent the actual data  So SyncML for the protocol  and JSON for the actual data being exchanged  Using JSON Array while manipulating the data is always preferred as it is easy to access data using JSON Array   Keeping track of data changes on both client and server  You can maintain a changelog of ids that change and pick them up during a sync session  Also  clear the changelog as the objects are successfully synchronized  You can also use a boolean variable to confirm the synchronization status  i e  last time of sync  It will be helpful for end users to identify the time when last sync is done   Need to have a way to communicate from the server to the device to start a sync session as data changes on the server  You can use C2DM or write your own persistent tcp based communication  The tcp approach is a lot seamless  A way to replicate data changes across multiple devices  And last but not the least  a way to detect and handle conflicts  Hope this helps as a good starting point

User · Answer

I ll try to answer all your questions by addressing the larger question  How can I sync data between a webserver and an android app     Syncing data between your webserver and an android app requires a couple of different components on your android device   Persistent Storage   This is how your phone actually stores the data it receives from the webserver  One possible method for accomplishing this is writing your own custom ContentProvider backed by a Sqlite database  A decent tutorial for a content provider can be found here  http   thinkandroid wordpress com 2010 01 13 writing-your-own-contentprovider    A ContentProvider defines a consistent interface to interact with your stored data  It could also allow other applications to interact with your data if you wanted  Behind your ContentProvider could be a Sqlite database  a Cache  or any arbitrary storage mechanism   While I would certainly recommend using a ContentProvider with a Sqlite database you could use any java based storage mechanism you wanted   Data Interchange Format   This is the format you use to send the data between your webserver and your android app  The two most popular formats these days are XML and JSON  When choosing your format  you should think about what sort of serialization libraries are available  I know off-hand that there s a fantastic library for json serialization called gson  https   github com google gson  although I m sure similar libraries exist for XML   Synchronization Service  You ll want some sort of asynchronous task which can get new data from your server and refresh the mobile content to reflect the content of the server  You ll also want to notify the server whenever you make local changes to content and want to reflect those changes  Android provides the SyncAdapter pattern as a way to easily solve this pattern  You ll need to register user accounts  and then Android will perform lots of magic for you  and allow you to automatically sync  Here s a good tutorial  http   www c99 org 2010 01 23 writing-an-android-sync-provider-part-1     As for how you identify if the records are the same  typically you ll create items with a unique id which you store both on the android device and the server  You can use that to make sure you re referring to the same reference  Furthermore  you can store column attributes like  updated at  to make sure that you re always getting the freshest data  or you don t accidentally write over newly written data

User · Answer

Grantismo provides a great explanation on the overall  If you wish to know who people are actually doing this things i suggest you to take a look at how google did for the Google IO App of 2014  it s always worth taking a deep look at the source code of these apps that they release  There s a lot to learn from there    Here s a blog post about it  http   android-developers blogspot com br 2014 09 conference-data-sync-gcm-google-io html  Essentially  on the application side  GCM for signalling  Sync Adapter for data fetching and talking properly with Content Provider that will make things persistent  yeah  it isolates the DB from direct access from other parts of the app    Also  if you wish to take a look at the 2015 s code  https   github com google iosched

User · Answer

one way to accomplish this to have a server side application that waits for the data  The data can be sent using HttpRequest objects in Java or you can write your own TCP IP data transfer utility  Data can be sent using JSON format or any other format that you think is suitable  Also data can be encrypted before sending to server if it contains sensitive information  All Server application have to do is just wait for HttpRequests to come in and parse the data and store it anywhere you want

[android] Sync data between Android App and webserver

Examples related to android

Examples related to android-syncadapter

[android] Sync data between Android App and webserver

Examples related to android

Examples related to android-syncadapter

Examples related to data-sharing