android.app.Application cannot be cast to android.app.Activity

Question

I'm trying to change a LinearLayout from another class, but when i run this code:

public class IRC extends PircBot {

ArrayList<String> channels;
ArrayList<Integer> userCount;
ArrayList<String> topics;

LinearLayout channelLayout;
Context context;

public IRC(Context ctx) {
    this.setName("xxxx");
    channels = new ArrayList<String>();
    userCount = new ArrayList<Integer>();
    topics = new ArrayList<String>();

    context = ctx;

    channelLayout = (LinearLayout) ((Activity) context).findViewById(R.id.channels);
}

i get a ClassCastException

context is the Main activity that extends Activity passed with a getApplicationContext();

LOGCAT

05-08 17:53:55.102    3736-3799/g.d.allinonechat E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-5357
java.lang.ClassCastException: android.app.Application cannot be cast to android.app.Activity
        at g.d.xxx.IRC.<init>(IRC.java:34)
        at g.d.xxx.MainActivity$1.run(MainActivity.java:49)
        at java.lang.Thread.run(Thread.java:856)

Herzl

Remove that try catch and Post your logcat.. – Mitchum

You shouldn't need (Activity) since you are using the Activity Context. Along with the logcat, you might want to post how you are passing the Context. – Cockneyism

What is IRC.java line no :34?? – Mitchum

Answer 1

You are passing the Application Context not the Activity Context with

getApplicationContext();

Wherever you are passing it pass this or ActivityName.this instead.

Since you are trying to cast the Context you pass (Application not Activity as you thought) to an Activity with

(Activity)

you get this exception because you can't cast the Application to Activity since Application is not a sub-class of Activity.

Cockneyism

This is an answer? is the same that log but with a lot of lines "ClassCastException: android.app.Application cannot be cast to android.app.Activity" A solution for me is to use "this" from an Activity – Whitver

@Whitver I don't understand your question. But yes this will work in an Activity which is why I suggested passing that since the OP was not in an Activity – Cockneyism

I was using context = getApplicationContext() changed it to context = this. solved the problem. – Emelda

Very good answer. This was a no nonsense answer. I was getting this error for a few day and when I read this answer, I corrected the association of context to the solution provided. – Schism

Saved all of us. Thank you! – Esme

Answer 2

in case your project use dagger, and then this error show up you can add this at android manifest

   <application
        ...
        android: name = ".BaseApplication"
        ...> ...

Jaynajayne

I'm not using dagger but it works for me. Thank you – Terzas

Answer 3

In my case, when I'm in an activity that extends from AppCompatActivity, it did not work(Activity) getApplicationContext (), I just putthis in its place.

Richardricharda

Answer 4

You are getting this error because the parameter required is Activity and you are passing it the Application. So, either you cast application to the Activity like: (Activity)getApplicationContext(); Or you can just type the Activity like: MyActivity.this

Lidalidah

Answer 5

In my case I just put android:name=".CustomBaseClass" inside the activity tag instead of the application tag inside the manifest, hope it helps someone.

Tomcat

Answer 6

You can also try this one.

override fun registerWith( registry: PluginRegistry) {
        GeneratedPluginRegistrant.registerWith(registry as FlutterEngine)       
    //registry.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin")
    }

I think this one is far better solution than creating a new class.

Proscription

Answer 7

I had a similar problem when checking for internet connection in my viewmodel. The error in my logcat:

java.lang.ClassCastException: android.app.Application cannot be cast to com.example.newsapplication.util.AppApplication in viewmodel

I added this line in the manifest and my application worked just fine.

  android:name="com.example.newsapplication.util.AppApplication"

Polymath

Answer 8

In my case, I just put add name property inside the application tag in the Manifest file

<application
    android:name=".TodoApplication"
    ...

Hoarhound

Answer 9

In my case I removed the line android:name ="<some_name>" and it worked. Looks like it was looking for a class with the name that was provided earlier whereas my Project does not have the class.

Membranophone

Answer 10

In my case, I deleted the android:name=".TodoApplication" from application and added it inside the activity tag.

<activity android:name=".BaseApplication"/>

Ensure you delete from the Application tag

Ask

Answer 11

I'm using Hilt in my project. I found problem at Module class. I converted SingletonComponent to ActivityComponent. I read that we shouldn't inject Activity to object that marked as @Singleton.

Boles

This is not an answer. If you have a question, please post it yourself – Russon

Pardon me, but it's not clear (to me, at least) whether you are answering the question or asking another question. Did converting SingletonComponent to ActivityComponent solve the problem? – Bala

yes solved my problem. Sorry for confusion. I just wanted to say While I'm implementing Hilt my module occurs this error so I searched and found this solution. – Boles