在Android 11中从最近使用的文件夹中选择PDF文件时，会出现NulllPointException:Uri

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE);
}

Uri selectedUri = data.getData();
if (selectedUri != null) {
    // 处理URI
} else {
    Log.e("URI Error", "Selected URI is null");
}

try {
    ContentResolver contentResolver = getContentResolver();
    InputStream inputStream = contentResolver.openInputStream(selectedUri);
    if (inputStream != null) {
        // 读取文件内容
        inputStream.close();
    } else {
        Log.e("File Error", "Failed to open input stream");
    }
} catch (IOException e) {
    e.printStackTrace();
}

public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_CODE = 123;

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

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE);
        } else {
            openFilePicker();
        }
    }

    private void openFilePicker() {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("application/pdf");
        startActivityForResult(intent, REQUEST_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
            Uri selectedUri = data.getData();
            if (selectedUri != null) {
                try {
                    ContentResolver contentResolver = getContentResolver();
                    InputStream inputStream = contentResolver.openInputStream(selectedUri);
                    if (inputStream != null) {
                        // 读取文件内容
                        inputStream.close();
                    } else {
                        Log.e("File Error", "Failed to open input stream");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                Log.e("URI Error", "Selected URI is null");
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == REQUEST_CODE && grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            openFilePicker();
        } else {
            Toast.makeText(this, "Permission denied", Toast.LENGTH_SHORT).show();
        }
    }
}