I have created a java servlet with which I have attached SQL database. Android client is sendig data to java servlet to save it in database which is working fine. I want to know if multiple android clients will share the same database connection or do i need to do some threading or something else?
Regards,
In my opinion You should synchronize databases on Android devices with servlet. Synchronization is not easy to make. I don't found ready class or library for it.
Maybe you find something on stackoverflow ;-)
Related
What I'm trying to do is connect a Java Android app with a FireBird database that is stored in an enterprise server.
I realised i need to use some kind of webserver to avoid connecting to the database directly.
In other words, something like this:
Android app -> WebServer -> Database
My problem is that although there are plenty of examples none of them let me do it.
Where can I find a full example of making the webserver, retrieve data (images, datasets, etc.) and how to connect my clients to it.
And obviously if there is a better way to do what I need that I'm not aware of.
Thanks in advance.
I've looked around trying to find an answer to this question, but have so far been unsuccessful. I have a current version of an Android mobile application that stores items in the local database, and I'm trying to hook it up to a 'cloud' database (not sure if this is the right term) so that other people that download the app will be able to view and post things to the database.
I have an ec2 service set up, with my LAMP stack installed. I have the database set up on this server ready to go. How do I go about hooking up the Android application so that it can communicate (insert/view/delete items) with the database? I am a new developer so any help/insight/guidance you have is much appreciated!
You haven't mentioned the type of database you have setup on cloud.
I am assuming it to be some kind of relational database (e.g. MySQL).
You can use standard JDBC connection from a regular java code but it is not yet possible (supported) to do it directly from Android code.
I faced a similar issue, what I did was this:
Create a Servlet and deployed it on GAE (Google App Engine).
Make an HTTP request from your android application code to this Servlet (SELECT/UPDATE/DELETE).
Initiate a JDBC connection to your database (on EC2) from that Servlet.
Shoot the SQL statement to the database.
Get the result and send the response back from servlet to your android code.
There may be other better solutions but I could not find any and tried this on my own, it worked like a charm, multiple times.
After writing the previous answer, I kept on thinking of alternate solution.
FYI: This may or may NOT work !
Instead of hosting your servlet on GAE, you can host it on the same EC2 instance as your database, using tomcat or any other package.
This way your android code would communicate directly with the instance that has servlet and database deployed together.
In the servlet, you can shoot SQL queries internally and send the results back to android code.
How to host a servlet in Tomcat 7
Adding new security group and linking it with my instance..worked for me
my application needs to store data locally on sqlite DB and user can upload data on server once the internet connection is available.
I assume I need to do some DB replication, how to accomplish that?
Is there any android built in facility?
Or I need to use some third party tool for that?
I read many answers on this but I am still not clear about it, I will use KSOAP2 web service for communicating with server.
Using KSOAP2 how can I Sync my sqlite data on SQL Server?
below are few links I read.
https://stackoverflow.com/questions/18207021/opensource-replication-tool-for-sqlite
Regarding sqlite replication
Does SQLite support replication?
Thanks in advance.
You shouldn't use dumps to copy the whole database back and forth. Android is running on mobile devices and datatransfer is likely to cost money or to be limited by speed or volumne or other means.
Therefore you should build your own webserver and upload/download only the changed entries. This means you will probably have to implement your own replication-logic, since I don't know any tools for that.
For example you can send a timestamp and the server replies with a set of changed data.
I'd recommend building a Restful-Webservice and using HttpUrlConnection to build POST, PUT, GET and DELETE requests.
GreenDao proposes a project for client/server-synchronization. But there is no estimation on when it will be available. If you do something yourself, you could try doing it as greendao-feature. A lot of people will thank you for that (myself included :D).
You can also have a look at symmetricDS, which should work on android.
I am trying to develop a real-time Android application where all contents are stored in server. So, they are available whenever a connection to Internet is available. Also, the application provides communication between users and conversations are stored in the server as well. Nothing is locally stored.
However, I am still cannot decide which database type I can use. I intended to use SQLite but I am not sure if I can really use it or not.
Could you please guide me to the proper database type to my application.
Appreciate your time and efforts.
As its upto you which database you use.
you may Install Lamp (For Linux) or WAMP(for window) . This is a nice database tool and very easy to handle and easy linked with PHP for various database function
I recently developed something similar to what you are talking about and here is what I would suggest you to go for.
Use SQL server to manage the data on your desktop and create a web-service in .Net on Visual Studio.
(Note that as others have already mentioned, it really does not matter what is the database you are using in your server end, because eventually the data is going to come to the Android application from the server in form of either xml or json in the web-service., regardless of what database you are using. So it is totally your wish which database you want to use.)
Then connect to the web-service in your application and set/get data from the remote Database, using SOAP.
Link on how to make a web-service in .NET (does not include the implementation in Android).
Links on how to connect your service with Android : this, this and this.
Is there any sample? I have my android application and I need to connect to mysql server on my machine, what is the best way?
I should not use jdbc, explanation here
Best way to implement Client <-> Server <-> Database architecture in an Android application?
Never never use a database driver across an Internet connection, for any database, for any platform, for any client, anywhere. That goes double for mobile. Database drivers are designed for LAN operations and are not designed for flaky/intermittent connections or high latency.
And should go for:
DefaultHttpClient httpclient = new DefaultHttpClient();
But there is no example in how to open a connection or execute a simple sql statement.
anyone could help me?
You should either use web services or implement an HTTP handler and transfer in a RESTful manner.
I'm a fan of Offline First, meaning your app should be usable without a connection.
To facilitate this, I would recommend using a SQLite local database, and syncing to a remote database when online.
You can use a tool like SymmetricDS or Daffodil Replicator to sync your local and remote databases over HTTP(S).
In order to connect to a MySQL server, you need a MySQL client. Android does not come with any MySQL libraries. You may be able to take a generic Java MySQL library and fudge it to work with Android, but that would be a big undertaking and wasted time.
The link you pointed to already told you that what you're trying to do is wrong in the first place. Don't connect to a database across the internet! You will need something on your server that responds to HTTP requests, looks up data in the database, and sends them back via HTTP. The link already mentioned a few options. You could even write something yourself, although it's most likely easier to use an existing solution than trying to make your own approach safe and hack-proof.
I tried to connect DatabaseServer from an Android Application,initially i faced some issue while i was using jtds, jar package for database Driver Support, instead of using jtds jar file use mysql-Connector jar file for Database Driver Support.
mysql-connector jar file "mysql-connector-java-5.1.24-bin.jar".
put this jar file in projects libs folder.
a little bit code snippet :
`String url="jdbc:mysql://(IP-of databaseServer):3306/DBNAME";`
`String driver="org.gjt.mm.mysql.Driver";`
`String username="XYZ";//user must have read-write permission to Database
`String password= "*********";`//user password
`try{
Class.forName(driver).newInstance();//loading driver
Connection con = DriverManager.getConnection(url,username,password);
/*once we get connection we can execute ths SQL command to Remote Database Server with the help mysql-connector driver over Internet*/
}`
`catch(Exception e){
e.printStackTrace();
}`
I hope it could work.
Cheers
Rajesh P Yadav.
You won't be able to connect directly to a MySQL database with the HttpClient, as the MySQL database doesn't operate on that protocol.
The second part of the answer to the question you linked recommends going with web services and consuming those to communicate with the database server. Which is exactly what you would be able to do with the HttpClient.
If you need to share data between multiple phones, I would recommend exposing it as a web service. If the data only needs to be accessible on that particular phone (and you want to remain relational) you can use sqlite.