Reusing the same code across multiple Android Studio projects

Question

I have some code I'd like to use across multiple different projects. Let's say it's some e-commerce code that handles things like payments and shopping carts.

It seems inefficient and dangerous to copy-paste everything across different projects. And if I add one feature or fix one bug in the core e-commerce module, I'd like that change to be reflected in other projects using it too.

I would also like to re-use some of the Activities, Fragments, Adapters too.

What is a good approach to this?

Answer 1

When we have a library project that needs to be shared to every project on a local computer, we can make use of Maven.

A. Here the step in your library that we will you for the project:

1. Make a library project from Android Studio.

2. Add Gradle Android Maven plugin to root build.gradle

   buildscript {
     repositories {
       mavenCentral()
     }
   
     dependencies {
       classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
     }
   }
   

3. Add apply plugin for step 1 in your library build.gradle. (NOT root build.gradle):

   apply plugin: 'com.android.library'
   apply plugin: 'com.github.dcendents.android-maven'
   

4. Add the following after the apply plugin, this line to determine your library when adding to project:

   group = 'com.yourpackage.yourlibrary'
   version = '1.0'
   

5. Add the following code in your settings.gradle:

   rootProject.name = 'yourlibrary' 
   

6. Then publish it to your local maven with:

   ./gradlew install
   

   Or you can use gradle option in Android Studio.

7. Your library will be installed in $HOME/.m2/repository. Remember that to use the library you need to add like this:

     Groupid:artifactid:versionid
   

   Artifactid will be package name of your library.

B. Here the step in your Project which using the library:

1. Add the following code in your root build.gradle:

     mavenLocal() // for local maven.
   

This for getting the local library maven that we have installed in step A

2. Then in your app project.gradle, add compile for the library:

   compile 'com.yourpackage.yourlibrary:yourlibrary:1.0'
   

Read more:

• Gradle: How to publish a Android library to local repository
• https://github.com/dcendents/android-maven-gradle-plugin
• https://inthecheesefactory.com/blog/how-to-upload-library-to-jcenter-maven-central-as-dependency/en