Java MultipartPloadRequest在向php服务器发送图像时正在为服务通知创建未知的无效通道

我已经创建了一个项目，需要使用android中的move_upload_文件将图像上传到PHP服务器。通过android，我使用MultipartPloadRequest将图像发送到服务器

首先错误出现在cursor变量上，当我删除该变量时，在添加权限后发生前台服务器错误some java.lang.RuntimeException:服务通知的通道无效

我的java代码

private Button buttonChoose;
private Button buttonUpload;
private ImageView imageView;
private EditText editText;

//Image request code
private int PICK_IMAGE_REQUEST = 1;

//storage permission code
private static final int STORAGE_PERMISSION_CODE = 123;

//Bitmap to get image from gallery
private Bitmap bitmap;

//Uri to store the image uri
private Uri filePath;

private String UPLOAD_URL = "http://10.0.2.2/rest/seller/upload.php";

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

    //Requesting storage permission
    requestStoragePermission();

    //Initializing views
    buttonChoose = (Button) findViewById(R.id.buttonChoose);
    buttonUpload = (Button) findViewById(R.id.buttonUpload);
    imageView = (ImageView) findViewById(R.id.imageView);
    editText = (EditText) findViewById(R.id.editTextName);

    //Setting clicklistener
    buttonChoose.setOnClickListener(this);
    buttonUpload.setOnClickListener(this);
}

public void uploadMultipart() {
    //getting name for the image
    String name = editText.getText().toString().trim();

    //getting the actual path of the image
    String path = getPath(filePath);

    //Uploading code
    try {
        String uploadId = UUID.randomUUID().toString();

        //Creating a multi part request
        new MultipartUploadRequest(this, uploadId, UPLOAD_URL)
                .addFileToUpload(path, "image") //Adding file
                .addParameter("name", name) //Adding text parameter to the request
                .setNotificationConfig(new UploadNotificationConfig())
                .setMaxRetries(2)
                .startUpload(); //Starting the upload

    } catch (Exception exc) {
        Toast.makeText(this, exc.getMessage(), Toast.LENGTH_SHORT).show();
    }
}


//method to show file chooser
private void showFileChooser() {
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
}

//handling the image chooser activity result
@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) {
        filePath = data.getData();
        try {
            bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
            imageView.setImageBitmap(bitmap);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

//method to get the file path from uri
public String getPath(Uri uri) {
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    cursor.moveToFirst();
    String document_id = cursor.getString(0);
    document_id = document_id.substring(document_id.lastIndexOf(":") + 1);
    cursor.close();

    cursor = getContentResolver().query(
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            null, MediaStore.Images.Media._ID + " = ? ", new String[]{document_id}, null);
    cursor.moveToFirst();
    String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
    cursor.close();

    return path;
}


//Requesting permission
private void requestStoragePermission() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED)
        return;

    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
        //If the user has denied the permission previously your code will come to this block
        //Here you can explain why you need this permission
        //Explain here why you need this permission
    }
    //And finally ask for the permission
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION_CODE);
}


//This method will be called when the user will tap on allow or deny
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

    //Checking the request code of our request
    if (requestCode == STORAGE_PERMISSION_CODE) {

        //If permission is granted
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            //Displaying a toast
            Toast.makeText(this, "Permission granted now you can read the storage", Toast.LENGTH_LONG).show();
        } else {
            //Displaying another toast if permission is not granted
            Toast.makeText(this, "Oops you just denied the permission", Toast.LENGTH_LONG).show();
        }
    }
}


@Override
public void onClick(View v) {
    if (v == buttonChoose) {
        showFileChooser();
    }
    if (v == buttonUpload) {
        uploadMultipart();
    }
}

我的Php代码

<?php

     require_once 'config.php';

     $upload_path = 'images/';

     $server_ip = gethostbyname(gethostname());

     $upload_url = 'http://' . $server_ip . '/rest/seller/' . $upload_path;

     $response = array();

     if ($_SERVER['REQUEST_METHOD'] == 'POST')
    {

    if (isset($_POST['name']) and isset($_FILES['image']['name']))
    {

    $con = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME) or die('Unable to Connect...');

    $name = $_POST['name'];

    $fileinfo = pathinfo($_FILES['image']['name']);

    $extension = $fileinfo['extension'];

    $file_url = $upload_url . getFileName() . '.' . $extension;

    $file_path = $upload_path . getFileName() . '.' . $extension;

    try
    {
        move_uploaded_file($_FILES['image']['tmp_name'], $file_path);
        $sql = "INSERT INTO `uploadimagetoserver` (`id`, `url`, `name`) VALUES (NULL, 
        '$file_url', '$name');";

        if (mysqli_query($con, $sql))
        {

            $response['error'] = false;
            $response['url'] = $file_url;
            $response['name'] = $name;
        }
    }
    catch(Exception $e)
    {
        $response['error'] = true;
        $response['message'] = $e->getMessage();
    }

    echo json_encode($response);

    mysqli_close($con);
}
else
{
    $response['error'] = true;
    $response['message'] = 'Please choose a file';
}

}

 function getFileName()
 {
$con = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME) or die('Unable to Connect...');
$sql = "SELECT max(id) as id FROM uploadimagetoserver";
$result = mysqli_fetch_array(mysqli_query($con, $sql));

mysqli_close($con);
if ($result['id'] == null) return 1;
else return ++$result['id'];
}

---

好的，我明白了，但是向上面的php服务器发送图像的最佳方式或实践是什么呢。请帮忙！

2020-10-14 13:19:59.878 8115-8115/market.example.marketapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: market.example.marketapplication, PID: 8115
android.app.RemoteServiceException: Bad notification for startForeground: java.lang.RuntimeException: invalid channel for service notification: Notification(channel=null pri=0 contentView=null vibrate=null sound=null defaults=0x0 flags=0x42 color=0x00000000 groupKey=net.gotev vis=PRIVATE)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1737)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
    2020-10-14 13:20:00.014 1917-1990/? E/InputDispatcher: channel '1d0ede 
     market.example.marketapplication/market.example.marketapplication.activity.SendImageActivity 
     (server)' ~ Channel is unrecoverably broken and will be disposed!
     2020-10-14 13:20:00.014 1917-1990/? E/InputDispatcher: channel '3e9882b 
     market.example.marketapplication/market.example.marketapplication.activity.LoginMainActivity 
     (server)' ~ Channel is unrecoverably broken and will be disposed!