I have an android app in which I have a login system and some other stuff that communicate with the server. Sometimes I just get from the web server just a confirmation and sometimes I get a lot of data. So far I was using a simple database. Today I implemented a Content Provider which is working so far. To get data from the ContentProvider I used this Cursor cursor = getContentResolver().query();, but I saw that there is also the option to use a CursorLoader. What is the difference between them ? In my case what should I use ? I also saw that I have to implement it in every class the cursorLoader, can't I make a single class for it and call it when it's needed ?
As the documentation states,
CursorLoader implements the Loader protocol in a standard way for querying cursors, building on AsyncTaskLoader to perform the cursor query on a background thread so that it does not block the application's UI.
This is the biggest advantage of using Loaders, i.e. it is asynchronous. Some of the other important advantages are also mentioned here.
- They provide asynchronous loading of data.
- They monitor the source of their data and deliver new results when the content changes.
- They automatically reconnect to the last loader's cursor when being recreated after a configuration change. Thus, they don't need to re-query their data.
If you use the default cursors by querying the content provider directly then you need to handle closing them, and as you said you have huge data, you'd have to run the query code on a different thread. For all these purposes using CursorLoaders is much simpler and efficient. For code on how to use one, check this out.
As to your second question,
I also saw that I have to implement it in every class the cursorLoader, can't I make a single class for it and call it when it's needed ?
You can very well make a Base class that will be implementing the loader callbacks and then you can inherit that base class from all the classes that need to use the CursorLoaders.