Error "package android.support.v7.app does not exist"

I am new to android development, and I have been using the command line tools to create an android project. I followed all the instructions given in the tutorial at android developers. However, they are focused more on IDE users.

When I tried extending my MainActivity class from ActionBarActivity instead of just Activity, it threw the following error.

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

It was complaining about this import statement.

import android.support.v7.app.ActionBarActivity;

I made sure to visit the SDK manager, and it says Android Support Library is installed. I am truly stumped on this one, and I would really appreciate any help you guys could give me.

This might help: http://developer.android.com/reference/android/support/v7/app/ActionBarActivity.html

First of all check if your project is using androidx or android support library. Check gradle.properties file:

android.useAndroidX=true

android.enableJetifier=true

If it contains the above lines, it is using androidx with an old code from some old tutorial.

In build.gradle (module:app)

Use

implementation 'androidx.appcompat:appcompat:1.0.0'

Instead of

compile 'com.android.support:appcompat-v7:28.0.0'

Also in MainActivity.java : Use

import androidx.appcompat.app.AppCompatActivity;

instead of :

import android.support.v7.app.AppCompatActivity;

If the issue reported from MainActivity.java then replace

import android.support.v7.app.AppCompatActivity;

with

import androidx.appcompat.app.AppCompatActivity;