Cannot load a java class/ layout file in android studio

Question

After successfully passing the login screen, I have called the AddJournalActivity.java class. . However, it crashes, as shown in the video. . What do I do? This is the code for AddJournalActivity.java

package com.project.journeyjournal;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.storage.StorageReference;

public class AddJournalActivity extends AppCompatActivity implements View.OnClickListener {
    private static final int GALLERY_CODE = 1;
    private Button saveButton;
    private ImageView addPhotoButton;
    private EditText titleEditText;
    private EditText thoughtsEditText;
    private ImageView imageView;


    private FirebaseAuth firebaseAuth;
    private FirebaseAuth.AuthStateListener authStateListener;
    private FirebaseUser user;

    //connection to firestore
    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private StorageReference storageReference;

    private CollectionReference collectionReference = db.collection("Journal");
    private Uri imageUri;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add_journal);

        firebaseAuth = FirebaseAuth.getInstance();
        titleEditText = findViewById(R.id.post_title_et);
        thoughtsEditText = findViewById(R.id.post_description_et);

        imageView = findViewById(R.id.post_imageView);
        saveButton = findViewById(R.id.post_save_journal_button);
        saveButton.setOnClickListener(this);
        addPhotoButton = findViewById(R.id.postCameraButton);
        addPhotoButton.setOnClickListener(this);

        authStateListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                user = firebaseAuth.getCurrentUser();
                if (user != null){

                } else{

                }

            }
        };

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.post_save_journal_button:
              //save Journal
              break;
            case R.id.postCameraButton:
                //get image from camera or gallery
                Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
                galleryIntent.setType("image/*");
                startActivityForResult(galleryIntent, GALLERY_CODE);
                break;
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == GALLERY_CODE && resultCode == RESULT_OK ){
            if (data != null){
                imageUri = data.getData();
                imageView.setImageURI(imageUri);//show image
            }
        }
    }

    @Override
    protected void onStart() {
        super.onStart();
        user = firebaseAuth.getCurrentUser();
        firebaseAuth.addAuthStateListener((authStateListener));
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (firebaseAuth!= null){
            firebaseAuth.removeAuthStateListener(authStateListener);
        }
    }
}

I tried opening other pages instead of AddJournalActivity after the login activity, and it was working fine. If I delete all the code in the.java file, then the layout file opens just fine. So I assume that the problem is with AddJournalActivity.java. But I am unable to find it.

I have added the Logcat if it helps. 2022-04-06 11:19:46.326 15573-15573/com.project.journeyjournal E/AndroidRuntime: FATAL EXCEPTION: main Process: com.project.journeyjournal, PID: 15573 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.journeyjournal/com.project.journeyjournal.AddJournalActivity}: java.lang.ClassCastException: androidx.cardview.widget.CardView cannot be cast to android.widget.ImageView at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3308) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3457) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2044) at android.os.Handler.dispatchMessage(Handler.java:107) at android.os.Looper.loop(Looper.java:224) at android.app.ActivityThread.main(ActivityThread.java:7560) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950) Caused by: java.lang.ClassCastException: androidx.cardview.widget.CardView cannot be cast to android.widget.ImageView at com.project.journeyjournal.AddJournalActivity.onCreate(AddJournalActivity.java:51) at android.app.Activity.performCreate(Activity.java:7893) at android.app.Activity.performCreate(Activity.java:7880) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3283) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3457) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2044) at android.os.Handler.dispatchMessage(Handler.java:107) at android.os.Looper.loop(Looper.java:224) at android.app.ActivityThread.main(ActivityThread.java:7560) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

Answer 1

I watched your video. Your app crashes after logging in.

By observing your logcat, I can see an error causing with CardView and ImageView. You didn't provide your XML Code, so I'm not sure what exactly is the cause.

Here check this line-

ComponentInfo{com.project.journeyjournal/com.project.journeyjournal.AddJournalActivity}: 
java.lang.ClassCastException: androidx.cardview.widget.CardView cannot be cast to android.widget.ImageView

Solution

Possibly you have a CardView in XML which has an ID post_imageView or postCameraButton and you're binding this ID to ImageView by calling

 imageView = findViewById(R.id.post_imageView);

or

 addPhotoButton = findViewById(R.id.postCameraButton);

Check your IDs in XML and let me know the update.