React Native (Android) - [ Changing application package name/bundle identifier ]

List of files to edit to change/rename your react-native android project. The following constants are used in the files to denote what kind of value should be placed.

APPLICATION_NAME - this will be used by react-native to identify your application. (settings.gradle, MainActivity.java, etc.)
APPLICATION_DISPLAY_NAME - display name in Android Home Screen.
ANDROID_PACKAGE_NAME - A valid android package name.

Please note that this is only to show what files to modify, the contents of the files are ommited inorder to emphasize the parts to change.

Files to modify

---------------------------------------------------
FILE                  |  PATH
---------------------------------------------------
app.json              |  ./
index.js              |  ./
package.json          |  ./
settings.gradle       |  ./android/
BUCK                  |  ./android/app/
build.gradle          |  ./android/app/
AndroidManifest.xml   |  ./android/app/src/main/
MainActivity.java     |  ./android/app/src/main/java/**
MainApplication.java  |  ./android/app/src/main/java/**
strings.xml           |  ./android/app/src/main/res/values

AndroidManifest.xml

<!-- ./android/app/src/main/AndroidManifest.xml -->
<!-- change the value of 'package' -->

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="ANDROID_PACKAGE_NAME">
    
</manifest>

BUCK

# ./android/app/BUCK

# find 'android_build_config' and 'android_resource'
# ANDROID_PACKAGE_NAME = com.mycompany.whaterver.app

android_build_config(
    name = "build_config",
    package = "ANDROID_PACKAGE_NAME",
)

android_resource(
    name = "res",
    package = "ANDROID_PACKAGE_NAME",
    res = "src/main/res",
)

MainActivity.java

// ./android/app/src/main/java/

/* NOTE: create a directory according to your package name
 * example: An android package name like, 'com.mycompany.sub.app'
 * will turn into 'com/mycompany/sub/app'
 * Now, manually create/put MainActivity.java under './android/app/src/main/java/com/mycompany/sub/app/'
*/

package ANDROID_PACKAGE_NAME;

import com.facebook.react.ReactActivity;

public class MainActivity extends ReactActivity {

    /**
     * Returns the name of the main component registered from JavaScript.
     * This is used to schedule rendering of the component.
     */
    @Override
    protected String getMainComponentName() {
        return "APPLICATION_NAME";
    }
}

MainApplication.java

// ./android/app/src/main/java/

// Similar to MainActivity.java
/* NOTE: create a directory according to your package name
 * example: An android package name like, 'com.mycompany.sub.app'
 * will turn into 'com/mycompany/sub/app'
 * Now, manually create/put MainActivity.java under './android/app/src/main/java/com/mycompany/sub/app/'
*/

package ANDROID_PACKAGE_NAME;

import android.app.Application;

import com.facebook.react.ReactApplication;

app.json

{
  "name": "APPLICATION_NAME",
  "displayName": "APPLICATION_DISPLAY_NAME"
}

build.gradle

# ./android/app/build.gradle

# find 'applicationId' under 'android.defaultConfig'
# android.defaultConfig.applicationId


android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"

    defaultConfig {
        applicationId "ANDROID_PACKAGE_NAME"
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
    }

index.js

import { AppRegistry } from 'react-native';
import App from './App';

AppRegistry.registerComponent('APPLICATION_NAME', () => App);

package.json

{
  "name": "APPLICATION_NAME",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest"
  },
  "dependencies": {
    "react": "16.3.1",
    "react-native": "0.55.3"
  }
}

settings.gradle

// ./android/settings.gradle

rootProject.name = 'APPLICATION_NAME'
include ':app'

strings.xml

<!-- ./android/app/src/main/res/values/strings.xml -->
<resources>
    <!-- NOTE: 
      This will be the name visible in the Android Home screen
    -->
    <string name="app_name">APPLICATION_NAME/APPLICATION_DISPLAY_NAME</string>
</resources>

markterence/React Native (Android) - Rename applicationID, package name.md