Причина: java .lang.NullPointerException: попытка вызвать виртуальный метод 'void android .widget.Button.setOnClickListener (android .view.View $ OnClickListener)' для ссылки на пустой объект
package com.example.andriod.societymaintenance;
public class NotceActivity extends AppCompatActivity {
private static final int PICK_IMAGE_REQUEST = 1;
private Button mButtonChooseImage;
private Button mButtonUpload;
private TextView mTextViewShowUploads;
private EditText mEditTextFileName;
private ImageView mImageView;
private ProgressBar mProgressBar;
private Uri mImageUri;
private StorageReference mStorageRef;
private DatabaseReference mDatabaseRef;
private StorageTask mUploadTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButtonChooseImage = findViewById(R.id.button_choose_image);
mButtonUpload = findViewById(R.id.button_upload);
mTextViewShowUploads = findViewById(R.id.text_view_show_uploads);
mEditTextFileName = findViewById(R.id.edit_text_file_name);
mImageView = findViewById(R.id.imageView);
mProgressBar = findViewById(R.id.progress_bar);
mStorageRef = FirebaseStorage.getInstance().getReference("uploads");
mDatabaseRef = FirebaseDatabase.getInstance().getReference("uploads");
mButtonChooseImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openFileChooser();
}
});
mButtonUpload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mUploadTask != null && mUploadTask.isInProgress()) {
Toast.makeText(NotceActivity.this, "Upload in progress", Toast.LENGTH_SHORT).show();
} else {
uploadFile();
}
}
});
mTextViewShowUploads.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
}
});
}
private void openFileChooser() {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(intent, PICK_IMAGE_REQUEST);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK
&& data != null && data.getData() != null) {
mImageUri = data.getData();
Picasso.get().load(mImageUri).into(mImageView);
}
}
private String getFileExtension(Uri uri) {
ContentResolver cR = getContentResolver();
MimeTypeMap mime = MimeTypeMap.getSingleton();
return mime.getExtensionFromMimeType(cR.getType(uri));
}
private void uploadFile() {
if (mImageUri != null) {
StorageReference fileReference = mStorageRef.child(System.currentTimeMillis()
+ "." + getFileExtension(mImageUri));
mUploadTask = fileReference.putFile(mImageUri)
.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
mProgressBar.setProgress(0);
}
}, 500);
Toast.makeText(NotceActivity.this, "Upload successful", Toast.LENGTH_LONG).show();
Upload upload = new Upload(mEditTextFileName.getText().toString().trim(),
taskSnapshot.getUploadSessionUri().toString());
String uploadId = mDatabaseRef.push().getKey();
mDatabaseRef.child(uploadId).setValue(upload);
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(NotceActivity.this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
})
.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
@Override
public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
double progress = (100.0 * taskSnapshot.getBytesTransferred() / taskSnapshot.getTotalByteCount());
mProgressBar.setProgress((int) progress);
}
});
} else {
Toast.makeText(this, "No file selected", Toast.LENGTH_SHORT).show();
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".NotceActivity">
<Button
android:id="@+id/button_choose_image"
android:layout_width="125dp"
android:layout_height="52dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:text="Choose"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.055"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.057" />
<EditText
android:id="@+id/edit_text_file_name"
android:layout_width="206dp"
android:layout_height="45dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:hint="Enter File Name"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.954"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.068" />
<ImageView
android:id="@+id/imageView"
android:layout_width="292dp"
android:layout_height="348dp"
android:layout_above="@+id/progress_bar"
android:layout_below="@+id/edit_text_file_name"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.441"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.452" />
<ProgressBar
android:id="@+id/progress_bar"
style="@style/Widget.AppCompat.ProgressBar.Horizontal"
android:layout_width="380dp"
android:layout_height="29dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.516"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.861" />
<Button
android:id="@+id/button_upload"
android:layout_width="100dp"
android:layout_height="71dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:text="Upload"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.051"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.975" />
<TextView
android:id="@+id/text_view_show_uploads"
android:layout_width="218dp"
android:layout_height="63dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:gravity="center"
android:text="Show Uploads"
android:textSize="16dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.73"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.964" />
</androidx.constraintlayout.widget.ConstraintLayout>