Script to update Gradle, Java and other Android project settings in a Flutter project

update-android-project.sh

#!/bin/bash
# Update Gradle, Java and other Android project settings in a Flutter project
# Works with both .gradle and .gradle.kts build files

# See: https://gradle.org/releases/
# See: https://developer.android.com/build/releases/gradle-plugin#compatibility
DESIRED_GRADLE_VERSION="8.11.1"
# Build errors often show the required Java version
DESIRED_JAVA_VERSION="17"
# See: https://developer.android.com/ndk/downloads
DESIRED_NDK_VERSION="27.0.12077973"
# Google Play Stores requires a minimum target SDK version
DESIRED_TARGET_SDK="35"
# The minimum Android SDK version
DESIRED_MIN_SDK_VERSION="24"
# This should be compatible with the DESIRED_GRADLE_VERSION set above
# See: https://developer.android.com/build/releases/gradle-plugin#updating-gradle
DESIRED_ANDROID_APPLICATION_VERSION="8.9.1"


# Exit if this is not a Flutter project
if [ ! -f "pubspec.yaml" ]; then
  echo "This is not a Flutter project"
  exit 1
fi

# Exit if the Android directory does not exist
if [ ! -d "android" ]; then
  echo "The Android directory does not exist"
  exit 1
fi

# Navigate to the Android directory
cd android

# Update Gradle version (if specified)
if [ -n "$DESIRED_GRADLE_VERSION" ]; then
  sed -i '' "s/gradle-.*-all.zip/gradle-${DESIRED_GRADLE_VERSION}-all.zip/" gradle/wrapper/gradle-wrapper.properties
fi

# Detect if using Groovy or Kotlin build gradle file
if [ -f "app/build.gradle.kts" ]; then
  BUILD_GRADLE="app/build.gradle.kts"
else
  BUILD_GRADLE="app/build.gradle"
fi

# Update Java version (if specified)
if [ -n "$DESIRED_JAVA_VERSION" ]; then
  sed -i '' "s/JavaVersion.VERSION_[0-9_]*/JavaVersion.VERSION_${DESIRED_JAVA_VERSION}/" "$BUILD_GRADLE"
fi

# Update NDK version (if specified)
if [ -n "$DESIRED_NDK_VERSION" ]; then
  sed -i '' "s/ndkVersion = .*/ndkVersion = \"${DESIRED_NDK_VERSION}\"/" "$BUILD_GRADLE"
fi

# Update minSdk version (if specified)
if [ -n "$DESIRED_MIN_SDK_VERSION" ]; then
  sed -i '' "s/minSdk = .*/minSdk = ${DESIRED_MIN_SDK_VERSION}/" "$BUILD_GRADLE"
fi

# Update targetSdk version (if specified)
if [ -n "$DESIRED_TARGET_SDK" ]; then
  sed -i '' "s/targetSdk = .*/targetSdk = ${DESIRED_TARGET_SDK}/" "$BUILD_GRADLE"
fi


# Update com.android.application version in settings.gradle (if specified)
if [ -n "$DESIRED_ANDROID_APPLICATION_VERSION" ]; then
  # Detect if using Groovy or Kotlin build gradle file
  if [ -f "settings.gradle.kts" ]; then
    sed -i '' "s/id(\"com.android.application\") version \".*\" apply false/id(\"com.android.application\") version \"${DESIRED_ANDROID_APPLICATION_VERSION}\" apply false/" settings.gradle.kts
  else
    sed -i '' "s/id \"com.android.application\" version \".*\" apply false/id \"com.android.application\" version \"${DESIRED_ANDROID_APPLICATION_VERSION}\" apply false/" settings.gradle
  fi
fi

echo "Android project updated. Run 'git diff android' to see the changes."

How to use:

• Download the script and add it to a folder in your system PATH
• Give it execution access (chmod +x update-android-project.sh)
• Tweak the versions if needed
• Run it from the root of your Flutter project

Looks good! But I would suggest to either change DESIRED_ANDROID_APPLICATION_VERSION name or add into a comment above information that this is Android Gradle Plugin (AGP) version. Also, instead of vague description for this variable This shouldn't be too old.. I would add a link to the official table of compatibility between Gradle version and Android Gradle Plugin versions: https://developer.android.com/build/releases/gradle-plugin

about:

echo "Android project updated. Run 'git diff' to see the changes or 'git reset --hard' to discard them."

I would prefer 'git checkoout -- .' to clean up the temporary changes, instead of 'git reset --hard' which could cause problems by accident

Hi Andrea!

Thank you for your helpful courses! I have an app almost finished, but I have massive problems with Gradle and have been trying to solve the problems for 4 weeks again and again via ChatGPT or Gemini. But it all goes in circles and I can't find a solution. No matter which solution I try, there are always problems with the apk. Even your script didn't help me.
In the Ios emulator I can run the app. That works. But it's all only finished when I can make the apk. Can you help me or is there anyone who could help me? Best regards Tobias

Thank you for sharing this script!

thanks for sharing

Thank
On Windows I need to remove all '' after -i

if [ -n "$DESIRED_GRADLE_VERSION" ]; then
  sed -i "s/gradle-.*-all.zip/gradle-${DESIRED_GRADLE_VERSION}-all.zip/" gradle/wrapper/gradle-wrapper.properties
fi

I've just updated the script to support both .gradle and .gradle.kts files.