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Duplicate class kotlin classes kotlin version 1.3.70

Error while adding MoshiPack Library in Kotlin latest version 1.3.70 to gradle.build application
Moshi pack
implementation 'com.daveanthonythomas.moshipack:moshipack:1.0.1'
Error Message
Duplicate class kotlin.reflect.KClasses found in modules jetified-kotlin-reflect-1.1.1.jar (org.jetbrains.kotlin:kotlin-reflect:1.1.1) and jetified-kotlin-stdlib-1.3.70.jar (org.jetbrains.kotlin:kotlin-stdlib:1.3.70)
Any suggestions how to solve this issue or any other library I can use in Kotlin so I can use Message Pack.
Thanks in advance

Try to add this to your dependencies:
implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
and make sure you specified your Android NDK location under File>Project Structure...>SDK Location

Starting Kotlin 1.3.70 some basic useful members on KClass included in Kotlin standard library (they were in a kotlin-reflect before).
See "Working with KClass" in https://blog.jetbrains.com/kotlin/2020/03/kotlin-1-3-70-released/
In your case MoshiPack adds a kotlin-reflect library that conflicts with standard library.
You should exclude transitive dependency to resolve the conflict.
If you use KotlinDSL, in build.gradle.kts:
implementation ("com.daveanthonythomas.moshipack:moshipack:1.0.1") {
exclude(group = "org.jetbrains.kotlin", module = "kotlin-reflect")
}
If you use Groovy, in build.gradle:
implementation ('com.daveanthonythomas.moshipack:moshipack:1.0.1') {
exclude group: 'org.jetbrains.kotlin', module: 'kotlin-reflect'
}

I tried this and it worked
implementation "org.jetbrains.kotlin:kotlin-reflect:1.4.10"

i think the only way to solve it , to go back to kotlin version 1.3.61 , so remove 1.3.70 and use 1.3.61

So I finally figured it out and here's how :-
So the main problem is you have injected 2 dependency of same class. Here he used 2 dependency for Kotlin which conflict in runtime to fix that you have to check which dependency is duplicated. (It is most case scenario. It can be with any other dependency i.e. Hilt)
Go to File > Project structure > Dependencies
Check which dependency are repeating. In this case it will have (androidx.core:core:1.8.0) and (androidx.core:core:+)
as you can see there are 2 dependency with same classes version 1.8.0 will have all the class which core:+ will have and this is causing a error.
Now delete (androidx.core:core:+) and hit Apply and sync project.
Now you should be good to go. here is structure after changing dependency.
Note:- This method will show all the android dependency which you might be not included but you will see all the dependency which any app has. Please remove the dependency who are you familiar with do not remove any dependency without any proper knowledge.

Library not adding its dependencies when used

I made a library, but when I tried to use it with implementation 'com.example:mylibrary:1.3.0' in my app's build.gradle, I keep getting an error saying the ConstraintLayout dependency (which the library uses but not the app) is not found. However it was explicitly defined in the library's build.gradle with implementation.
When I ran gradlew app:dependencies on the terminal, it shows that the library has no dependencies, even though it actually has 2. This seems to be the source of the problem, Gradle can't detect the dependencies of the library.
I didn't run into this problem for a while but when I decided to remove the ConstraintLayout dependency from my app an error appears during build.

When you're using implementation for the dependencies in your library, the project which is dependent with it will not see the dependencies. You need to use api instead of implementation.

How to get a compile error if a JAR dependency is missing?

I have an Android project with the following dependencies:
-- Android App
---> MySDK.Jar
------> 'org.apache.commons:commons-lang3:3.5'
This is MySDK.jar that has a dependency on commons-lang3.
I'm working on Android Studio and I'm thus using Gradle.
Here is my problem:
I have shared "MySDK.Jar" to someone and he has built his own Android App on top of it.
It works but we have seen that the compiler doesn't notice the missing dependency on 'org.apache.commons:commons-lang3:3.5'. At run-time there will be a crash if the code using 'org.apache.commons:commons-lang3:3.5' is called. One may not notice the problem if he doesn't call the code using this library.
I know that we can solve this issue by adding the following line to Android App build.gradle file:
compile 'org.apache.commons:commons-lang3:3.5'
I'm wondering if there is a way to get a compile error indicating such missing dependencies? It is indeed better to see the dependency problem at compilation time rather than at runtime.
What are the recommended good practices for this?
Thanks!

commons-lang3 is a transitive dependency of Android App. As such, it is often not needed for compilation - there are exceptions, especially regarding multiple levels of inheritance. So at compile time you (usually) do not know whether you miss a transitive dependency that you need at runtime.
This is where Gradle comes in. Gradle can (as Maven) resolve dependencies transitively from a Maven repository (as MavenCentral). If you put MySDK into a Maven repository (like Nexus or Artifactory, which have open source versions), everyone using MySDK will automatically draw commons-lang3 so you will not miss anything at runtime.

If you are just adding the jar file in your project you can't warning about the missing dependencies.
To do it you have to publish the jar file in a maven repo.
In this way you have a pom file which describes the dependencies that gradle has to download.

Provide a method like MySDK.init() int your MySDK.jar,call a method whe is belong to org.apache.commons:commons-lang3:3.5' in the MySDK.init() method, then put init() into onCreate() of your Application,
Another way is，putorg.apache.commons:commons-lang3:3.5 into MySDK.jar，
Hope it helps you :)

How to use only one library (are multiple same ones)

Situation is that I in my project use library A. I also import external library which also has itself a library A. So as you can assume, when I try to compile, I receive Multiple DEX files define error which means that there are duplications.
However, If I remove my library from the project, I cannot use its provided methods. And I cannot find how can I remove that library from the module.
Any suggestions?

You should be able to exclude it like this:
compile('library:1.0.0') {
exclude group: 'something', module: 'something'
}
So do this on the external library for all the things you're using that's causing a problem.
From here: https://discuss.gradle.org/t/how-to-exclude-transitive-dependency/2119/2

define multiDexEnable True in your build.gradle(app)
defaultConfig {
multiDexEnabled true
}
and also define in dependency in same build.gradle(app)
compile 'com.android.support:multidex:1.0.1'

Thank you guys for your suggestions.
I didn't want to do as Michael suggested because I believe it is kind of useless (having multiple libraries with same purpose) (already knew this trick).
I have tried Ядм Жцмдшдт answer, but couldn't succeed in compiling code completely. I have received various errors.
In the end I have solved my own issue. What I did:
Remove library from my main app libs folder. Remove dependancies if any in Android Studio (File -> Project Structure -> Dependencies (On module app) -> remove if any regarding your library.
Clean project in Android Studio (Build -> Clean Project).
Go to the module where my library A is. Go to that module build.gradle file and add following line in the dependencies cluster
compile files('libs/libraryA.jar')
Sync code and enjoy results.
TLDR
I didn't have libraryA compiled in my external module but it threw me duplication error, that's where I was confused. By removing it from my main project and adding it to my module's compilations list solved the problem.

How to import a library from github?

I don't understand how to add a library in my new project.
https://github.com/txusballesteros/bubbles-for-android
I saw similar posts but I don't get the library in my project.
Error:Configuration with name 'default' not found.
And when I add the library can I change the original source code and can I use it because I read about the same License ?
Please help me, I was trying many methods and I failed.

Locate your build.gradle file:
Go to android view (easiest this way)
Locate Gradle Scripts folder:
Locate your correct build.gradle file (watch it, there are 2 of those who look similar):
Add the this statement (compile 'com.txusballesteros:bubbles:1.2.1') according to picture:
Good to go

Add the library dependency in your app level build.gradle file(not project level). you don't need to download any library file just add this dependency and sync the project
dependencies {
...
compile 'com.txusballesteros:bubbles:1.2.1'
}

Add following to your Build.Gradle under dependency block and then sync. project. Now you can use that library methods in your code.
compile 'com.txusballesteros:bubbles:1.2.1'