error: package android.support.v7.widget does not exist

Question

I'm trying to use an SDK given with the RFID scanner I recently bought.
I'm trying to run the sample code given, but it won't compile. I get the following errors on compilation:

error: package android.support.v7.widget does not exist
error: package RecyclerView does not exist

I've tried all the solutions on similar posts, and I'm pretty sure I have the support library correctly installed.

Here are all my dependencies in my build.gradle (app)

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0-rc01'
implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
implementation 'com.google.android.material:material:1.1.0-alpha08'
testImplementation 'junit:junit:4.13-beta-3'
androidTestImplementation 'androidx.test:runner:1.3.0-alpha02'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0-alpha02'
implementation project(':Rfid.AsciiProtocol-Library')
implementation 'com.android.support:appcompat-v7:+'
implementation 'com.android.support:recyclerview-v7:26.0.0'

}

I'm new to Android Studio, and as I said I tried pretty much all the answers for similar problems and nothing works, so I would appreciate any help.

Answer 1

You should replace android support recyclerview with androidx

implementation 'androidx.recyclerview:recyclerview:1.0.0'

And you can delete 'com.android.support:appcompat-v7:+' dependency, because you've already import it with

implementation 'androidx.appcompat:appcompat:1.1.0-rc01'

Answer 2

It frustrated me for literally hours because the answer here given is missing so much.

In dependencies of gradle: import:

implementation 'androidx.recyclerview:recyclerview:1.0.0'

click gradle sync (should be a bar on top of the page that pops up

Then in your java file where u actually use the RecyclerView class, import this:

import androidx.recyclerview.widget.RecyclerView;

and you are done

EDIT: So apprently you just need to auto-fill the object you need and android studio will auto inport for you. example: try to type recyclerview, but press tab to auto-fill it. The object should automatically be imported for you on top of the java page. This works with all android studio objects like view and intent.