Troubleshooting: Could not initialize class org.codehaus.groovy.reflection.ReflectionCache

I am a Ionic Capacitor user, I didn’t know since when my android build keep failing and no clue what’s the cause.

And I keep getting these errors when I run “npx cap add android”:

	
Syncing GradleError running gradle sync Starting a Gradle Daemon, 1 stopped Daemon could not be reused, use --status for details

java.lang.NoClassDefFoundError: Could not initialize class org.codehaus.groovy.vmplugin.v7.Java7

… #skipped verbose error messages

FAILURE: Build failed with an exception.


* What went wrong:
Could not initialize class org.codehaus.groovy.reflection.ReflectionCache


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org
BUILD FAILED in 21s

Unable to infer default Android SDK settings. This is fine, just run npx cap open android and import and sync gradle manually
	

The Solution

Firstly, you'll to know which java version is your android studio is using, find the info in "About Android Studio". 

Set environment variable to point JAVA_HOME to the path where openjdk version of "1.8.0_242-release” (or embedded jdk inside Android Studio app folder) located. On Mac, it's usually 

/Applications/Android Studio.app/Contents/jre/jdk/Contents/Home

MacOS (Android Studio 4.1.1):

export JAVA_HOME="/Applications/Android Studio.app/Contents/jre/jdk/Contents/Home"

jenv User:

You can add Android Studio embedded openjdk path to your jenv and then switch to your prefered java version with jenv local VERSION_NO for local or  jenv global VERSION_NO for system wide.

jenv add "/Applications/Android Studio.app/Contents/jre/jdk/Contents/Home"

Window:

Add/update environment variable JAVA_HOME and point it to path where the correct version of openjdk extracted.

Troubleshooting Custom Capacitor Plugin: No such module 'PushNotifications'

As a Capacitor hybrid app developer, default plugins offered by Capacitor can be not enough to achieve what we want for our project.

For beginner like me, who hope to create a simple custom plugin, set aside Javascript related code, it can be a tough experience as we have to learn and put into practise for both Android and iOS build.

Building a custom plugin for Capacitor (Ionic)

Fortunately, Capacitor has built-in API we could use to build any custom plugin.

No such module 'PushNotifications' (iOS)

On one of my custom plugin, it has dependency on Pusher's client iOS SDK which is imported through cocoapod. Running app "build" on xcode on this plugin is successful.

On my ionic app project folder, when import the created custom plugin causes error, and I get 

"No such module 'PushNotifications'" 

for importing the custom plugin. Which it's weird as I've checked and certain PushNotifications plugin installed in pods folder on both the actual app project and in the custom plugin.

When I navigate inside xcode Pods project, I'm able to see PushNotifications library correctly placed under pods folder.

Solution:

1. In the Capacitor custom plugin folder, find the .podspec file (usually located at root folder of your Plugin project), and add s.xcconfig to your podspec file, it's added to tell xcode about where to look the PushNotifications framework required by this plugin in your main project.

	
		
  require 'json'

  package = JSON.parse(File.read(File.join(__dir__, 'package.json')))

  Pod::Spec.new do |s|
    s.name = 'CapacitorPusherBeams'
    s.version = package['version']
    s.summary = package['description']
    s.license = package['license']
    s.homepage = package['repository']['url']
    s.author = package['author']
    s.source = { :git => package['repository']['url'], :tag => s.version.to_s }
    s.source_files = 'ios/Plugin/**/*.{swift,h,m,c,cc,mm,cpp}'
    s.ios.deployment_target  = '11.0'
    s.dependency 'Capacitor'
    s.swift_version = '5.0'
    s.xcconfig = { 'FRAMEWORK_SEARCH_PATHS' => "${PODS_CONFIGURATION_BUILD_DIR}/PushNotifications" }
  end

	

2. Or, alternatively, you can add the PushNotification framework path manually as below (you'll have to do this every time when the plugin get updated or after you run npx cap update)

Steps

1. Go to Pods project's Build settings, find "Framework Search Paths"
2. Select your affected plugin (by the missing module error mentioned above)
3. Add the missing path to both Debug and Release as needed.