What is the best practice for putting classes under package names in Android

Question

Android Studio 0.8.11

Hello,

I have just completed a test on Android which was to build an app that takes a live news feed, and display them. However, the instructor was very critical as I put all my classes under one package.

I am just wondering what is the best practice for packaging classes. For my particular test I have the following classes under this package name:

com.viewsys.ncon

My classes were these:

DBHelper          <-- database creating and ugprading
DetailActivity    <-- activity that add the NconDetailFragment
NconContract      <-- properties of the database schema columns, table name
NconDetailFragment <-- detail fragment
NconListFragment  <-- list fragment
NconViewPager  <-- just the view pager
JsonNewsFeed   <-- class that downloads and parses the json format
MainActivity   <-- Main activity
NewsFeed       <-- class of properties getters/setters for news feed
NewsFeedDB     <-- simple array list to store all the object from the sqlite3 DB
SplashActivity <-- activity that add the splashFragment and the NconListFragment
SplashFragment <-- splash fragment
Utilities <-- just some simple utility functions

Many thanks for any suggestions,

Answer 1

First you could separate by Model (classes holding your data) and view (everything for the display) and then you could create subpackages for different types of classes.

For Example:

com.viewsys.ncon

Utilities

com.viewsys.ncon.model

NconContract
JsonNewsFeed
NewsFeed

com.viewsys.ncon.model.db

DBHelper
NewsFeedDB

com.viewsys.ncon.view

NconViewPager

com.viewsys.ncon.view.activities

DetailActivity
MainActivity
SplashActivity

com.viewsys.ncon.view.fragments

NconDetailFragment
NconListFragment
SplashFragment

You should try to minimize package dependency cycling. That means one package can depend on an other (or multiple other) package and use their classes but the required package should minimize the dependency to the first package. so the dependeny calls should only go into one direction.

Answer 2

Please take a look in this repository, it presents the best practices for android development, and one of these practices is the java package architecture.

In a nutshell, you can do like this:

com.business.project
├─ network
├─ models
├─ managers
├─ utils
├─ fragments
└─ views
   ├─ adapters
   ├─ actionbar
   ├─ widgets
   └─ notifications

Activities and fragments are not classified as views, because they are controllers, but they also handles the view, so put in their own packages.