Create an Android application on the command line, without Android Studio

create_apk.sh

# From the current working directory...

mkdir -p app/src/main/res/values
mkdir -p app/src/main/res/layout
mkdir -p app/src/main/java/com/example/helloworld
cat > app/src/main/AndroidManifest.xml << _EOF
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.helloworld">

<application
        android:label="Hello World"
        android:theme="@style/AppTheme"> <!-- Use the AppCompat theme here -->
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>
_EOF

cat > app/src/main/java/com/example/helloworld/MainActivity.java << _EOF
package com.example.helloworld;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TextView textView = new TextView(this);
        textView.setText("Hello, World!");
        setContentView(textView);
    }
}
_EOF

cat > app/src/main/res/values/styles.xml << _EOF
<resources>
    <!-- Base application theme -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here -->
    </style>
</resources>
_EOF

cat > build.gradle << _EOF
buildscript {
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:8.0.0'
    }
}
_EOF

cat > settings.gradle << _EOF
pluginManagement {

    /**
      * The pluginManagement.repositories block configures the
      * repositories Gradle uses to search or download the Gradle plugins and
      * their transitive dependencies. Gradle pre-configures support for remote
      * repositories such as JCenter, Maven Central, and Ivy. You can also use
      * local repositories or define your own remote repositories. The code below
      * defines the Gradle Plugin Portal, Google's Maven repository,
      * and the Maven Central Repository as the repositories Gradle should use to look for its
      * dependencies.
      */

    repositories {
        gradlePluginPortal()
        google()
        mavenCentral()
    }
}
dependencyResolutionManagement {

    /**
      * The dependencyResolutionManagement.repositories
      * block is where you configure the repositories and dependencies used by
      * all modules in your project, such as libraries that you are using to
      * create your application. However, you should configure module-specific
      * dependencies in each module-level build.gradle file. For new projects,
      * Android Studio includes Google's Maven repository and the Maven Central
      * Repository by default, but it does not configure any dependencies (unless
      * you select a template that requires some).
      */

    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
    }
}
rootProject.name = "android"
include ':app'
_EOF

cat > app/build.gradle << _EOF
apply plugin: 'com.android.application'

android {
    namespace 'com.example.helloworld'
    compileSdkVersion 30
    defaultConfig {
        applicationId "com.example.helloworld"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation 'androidx.appcompat:appcompat:1.3.1'
}
_EOF

cat > gradle.properties << _EOF
android.useAndroidX=true
_EOF

# Install the sdk using the command line tools (sdkmanager)
echo y | sdkmanager "platforms;android-30" --sdk_root=/tmp/data/sdk

# Stupid license accepts..
printf "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"| sdkmanager --licenses  --sdk_root=/tmp/data/sdk

# Define the SDK location within gradle
cat > local.properties << _EOF
sdk.dir=/tmp/data/sdk
_EOF

# Initialize the wrapper
gradle wrapper

./gradlew assembleDebug

# Install on the device
adb install ./app/build/outputs/apk/debug/app-debug.apk