AWSMobile vs Amplify

Question

I have recently inherited some old code from a project. It is being repurposed a plugin for ATAK (Android Tactical Assault Kit) and it needs to use AWS Amplify to upload and download files from AWS S3. The original creator of the code used AWS amplify for uploading files.

Now, when I try setting up AWS amplify in the CLI (following the AWS Mobile Development Guide), I notice that everything goes smoothly with running amplify init, amplify add auth, amplify add storage, and amplify add API. That's all fine.

Next, I added the dependencies to my Gradle file inside of my build.gradle (:app) file. That also worked fine and synced.

Now, the code never actually gets past the AWS.configure part shown below:

            Amplify.addPlugin(new AWSCognitoAuthPlugin());
            Amplify.addPlugin(new AWSCognitoAuthPlugin());
            Amplify.addPlugin(new AWSS3StoragePlugin());
            com.atakmap.coremap.log.Log.i(TAG, "Amplify Plugin configure!");
            com.atakmap.coremap.log.Log.i(TAG, "Amplify: (plugin == null) == " + Boolean.toString(plugin == null));
            Amplify.configure(plugin);

            com.atakmap.coremap.log.Log.i(TAG, "Amplify Plugin configure Afterwards!!");
            android.util.Log.i("MyAmplifyApp", "Initialized Amplify");
        } catch (AmplifyException error) {
            android.util.Log.e("MyAmplifyApp", "Could not initialize Amplify", error);
        }

2021-04-13 15:09:58.824 27642-27642/com.atakmap.app.civ E/MyAmplifyApp: Could not initialize Amplify
    AmplifyException {message=Failed to instantiate AWSMobileClient, cause=java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference, recoverySuggestion=See attached exception for more details}
        at com.amplifyframework.auth.cognito.AWSCognitoAuthPlugin.configure(AWSCognitoAuthPlugin.java:87)
        at com.amplifyframework.core.category.Category.configure(Category.java:13)
        at com.amplifyframework.core.Amplify.configure(Amplify.java:17)
        at com.amplifyframework.core.Amplify.configure(Amplify.java:1)
        at com.atakmap.android.helloworld.recyclerview.RecyclerViewDropDown.<init>(RecyclerViewDropDown.java:200)
        at com.atakmap.android.helloworld.HelloWorldDropDownReceiver.<init>(HelloWorldDropDownReceiver.java:653)
        at com.atakmap.android.helloworld.HelloWorldMapComponent.onCreate(HelloWorldMapComponent.java:254)
        at com.atakmap.android.helloworld.plugin.HelloWorldLifecycle.onCreate(HelloWorldLifecycle.java:78)
        at com.atak.plugins.impl.LifecycleMapComponent$2.run(SourceFile:142)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
        at com.amazonaws.mobile.auth.core.IdentityManager.<init>(IdentityManager.java:207)
        at com.amazonaws.mobile.client.AWSMobileClient$2.run(AWSMobileClient.java:482)
        at com.amazonaws.mobile.client.internal.InternalCallback$1.run(InternalCallback.java:101)
        at java.lang.Thread.run(Thread.java:764)

I have a few questions.

AWS Mobile seems to be deprecated.

If the code that is causing the issue refers to AWS Mobile, is there a way to get around this error without having to use AWSMobile, and if so, where should I look?

Answer 1

AWS Mobile seems to be deprecated.

You're using AWS Amplify, which as of 2021 is the current generation product.

Amplify.addPlugin(new AWSCognitoAuthPlugin());
Amplify.addPlugin(new AWSCognitoAuthPlugin());

It looks like you're adding this plugin twice; you should only add a unique plugin once.

setting up AWS amplify in the CLI

Note that the Amplify Storage category requires the Amplify Auth category. Did you run amplify add auth, too? The CLI will generate a file at app/src/main/res/raw/amplifyconfiguration.json. Inspect this file to ensure that it contains information about both Authentication and Storage.

Lastly --

Amplify.configure(plugin);

The configuration method above is meant to take an Android Context. It's not clear to me what's being passed in, but it has a strange name ("plugin".)