Android Studio build flavors - How to have same source files in diverse flavors

问题

I need to create a demo flavor in android studio for an app. In my app level gradle file i have created another flavor called demo and the default flavor of full of course. It looks like this:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "com.example.uen229.myapplication"
        minSdkVersion 17
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    productFlavors {
        demo {
            applicationId "com.buildsystemexample.app.demo"
            versionName "1.0-demo"
        }
        full {
            applicationId "com.buildsystemexample.app.full"
            versionName "1.0-full"
        }
    }

}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
}

and here is a image of my project structure in which I have created a demo flavor directory:

Now onto the issue. I have two classes called Hello.java. Both are in there respective flavors and print different things. I'll show you both files now:

import android.util.Log;

/** this is from demo flavor directory**/

public class Hello {

    Hello(){

        Log.v("","hello from demo");
    }

    public String getName();
        return "im from demo";

    };

}

And here is the other Hello:

package com.example.uen229.myapplication;

import android.util.Log;


/** this is from full or main flavor directory**/
public class Hello {


    Hello(){

        Log.v("", "hello from main");
    }

    public String getName(){

        return "im from main";

    };
}

notice how the first hello.java does not have package, even if i had a package the IDE wont compile. look at this photo:

Now finally lets look at mainActivity.java to see that when i switch build variants it only does a toast for "im from main" but i need it to print 'im from demo" if i use the demoDebug build variant. If i switch the build variant to demoDebug it still prints "im from main". can anyone help :

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Hello h = new Hello();
        Toast.makeText(this, h.getName(), Toast.LENGTH_LONG).show();

    }
}

UPDATE

From stackoverflow it says:

If you want to have a different version of the same class in the two flavor you'll need to create it in both flavors.

src/flavor1/java/com/foo/A.java

src/flavor2/java/com/foo/A.java

And then your code in src/main/java can do:

import com.foo.A

depending on the flavor selected, the right version of com.foo.A is used.

This is what I want to accomplish with the Hello class

回答1:

I think you can't have same class in main flavor and your other flavor. you should just create another flavor, then move your Hello class from main flavor to that new flavor. this rule is just for .java files. I mean you can have an xml file in main flavor and another version in your custom flavor but you can't do this with java files.

here is a useful link with further explanation.

回答2:

I would advice to create 3 source sets:

• main - which would contain common classes
• demo - contains demo specific classes
• pro - contains classes for pro versions

and declare them using:

sourceSets {
    main {
        manifest.srcFile 'AndroidManifest.xml'
        java.srcDirs = ['src/main/java']
        res.srcDirs = ['src/main/res']
        assets.srcDirs = ['src/main/assets']
    }
    pro {
        manifest.srcFile 'src/pro/AndroidManifestPro.xml'
        java.srcDirs = ['src/main/java', 'src/pro/java']
    }
    demo {
        manifest.srcFile 'src/oldlite/AndroidManifestDemo.xml'
        java.srcDirs = ['src/main/java', 'src/demo/java']        
    }
}

P.S. not really sure about syntax of java.srcDirs content - please double check yourself

回答3:

I was able to override classes but the key was not to include the class in my main folder.

So the fullDebug (i.e. main folder) build variant will never get run. Always run a flavor and not the main folder. The main folder will just be used to keep common things in it.

In my case I had a demo for USA and another country (demo and demo_us)and I needed two flavors. I'll always build for either of the two and won't build main.

From the image you can see I made all my package names to be the same: like com.example.******.myapplication. Since they all have the same package name in the MainActivity you just import Hello.java with that package name and it will pick the right variant at build time.

For resources it looks like it's different and it will override naturally but java class files have to do this way.

来源：https://stackoverflow.com/questions/31016283/android-studio-build-flavors-how-to-have-same-source-files-in-diverse-flavors