(Android & Firebase) Cannot resolve symbol 'dataSnapshot'

Question

I don't know why dataSnapshot doesn't work.

symbol: variable dataSnapshot

private void Startplaylist(String mood) {
        DatabaseReference p_ref = FirebaseDatabase.getInstance().getReference("Playlist");
        //DatabaseReference p_music = (DatabaseReference) p_ref.child("Playlist_Mood").equalTo(mood);
        p_ref.child("Playlist_ID").equalTo(0).addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                music_id = dataSnapshot.getValue("Playlist_Id"); // Problem HERE!!
                str_musictitle.setText(music_id);
                    //music_id = snapshot.getValue(String.class);
                    //str_musictitle.setText(music_id);
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

This is my build.gradle(Module: app) code.

dependencies {
    /-- fire storage--/
    implementation 'com.github.bumptech.glide:glide:4.11.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'

    implementation platform('com.google.firebase:firebase-bom:28.4.1')
    implementation 'com.google.firebase:firebase-analytics'
    implementation 'com.google.firebase:firebase-database:19.2.0'
    implementation 'androidx.appcompat:appcompat:1.3.1'
    implementation 'com.google.android.material:material:1.3.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
    implementation 'com.google.firebase:firebase-database:19.2.1'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
}

I searched hard and looked for a solution, but I couldn't solve it, so I asked a question.

Answer 1

You are seeing that dataSnapshot in red because there is no such object present in your code. Most likely you should use the snapshot object that is present as an argument. So please change the following line of code:

music_id = dataSnapshot.getValue("Playlist_Id");

To:

music_id = snapshot.getValue("Playlist_Id");