如何使用Android Studio获取PDF文件路径？

Question

我正在研究项目，因为我必须上传PDF文件或DOC文件，但是我写了太多代码但没有成功 每当我单击“提交吐司”时，说“上传PDF文件并退出活动”。 如何解决问题？

这是我使用的代码

public class contactus extends AppCompatActivity {

EditText name,email,mobile;
Button submit,uploadCv;

public static final String pdfurl = "https://umsctest.000webhostapp.com/testdb/upload.php";
Uri uri;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contactus);

    name = findViewById(R.id.et_name);
    email = findViewById(R.id.et_email);
    mobile = findViewById(R.id.et_no);

    submit = findViewById(R.id.bt_submit);
    uploadCv = findViewById(R.id.bt_uploadCv);

    InputFilter[] inputFilter = new InputFilter[1];
    inputFilter[0] = new InputFilter.LengthFilter(10);
    mobile.setFilters(inputFilter);

    uploadCv.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
           uploadfile();
        }
    });


    submit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String fname = name.getText().toString();
            String mail = email.getText().toString();
            String mob = mobile.getText().toString();
            String filepath = FilePath.getPath(contactus.this,uri);

            if (filepath == null)
            {
                Toast.makeText(getApplicationContext(),"Please Upload PDF file",Toast.LENGTH_SHORT).show();
            }else
            {
                String pdfId = UUID.randomUUID().toString();
                try {
                    new MultipartUploadRequest(contactus.this,pdfId,pdfurl).addFileToUpload(filepath, "pdf")
                            .addParameter("name",fname)
                            .addParameter("email",mail)
                            .addParameter("mobile",mob)
                            .setNotificationConfig(new UploadNotificationConfig())
                            .setMaxRetries(5)
                            .startUpload();
                } catch (FileNotFoundException e) {
                    Toast.makeText(getApplicationContext(),"Error in Uploading Fis",Toast.LENGTH_SHORT).show();
                    e.printStackTrace();
                } catch (MalformedURLException e) {
                    Toast.makeText(getApplicationContext(),"Error in Uploading File",Toast.LENGTH_SHORT).show();
                    e.printStackTrace();
                }
            }
if (fname.length() <=0)
            {
                name.setError("Name Please");
            }else if (mail.length() <=0)
            {
                email.setError("Email Please");
            }else if (mob.length() <=0)
            {
                mobile.setError("WhatsApp No. Please");
            }else if (mob.length() >10)
            {
                mobile.setError("Only 10 Digits No.");
            }else
            {
                name.setText("");
                email.setText("");
                mobile.setText("");
            }
        }
    });


}
private void uploadfile() {

    Intent intent = new Intent();
    intent.setType("application/pdf");
    intent.setAction(intent.ACTION_GET_CONTENT);
    startActivityForResult(intent.createChooser(intent,"Select Pdf"),1);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 1 && resultCode == RESULT_OK && data !=null)
    {
        Uri path = data.getData();
        uploadCv.setText("PDF Selected");
    }
}

这是我的contactus（mainactivity）.java

我也使用了FilePath.java

public class FilePath {

public static String getPath(final Context context, final Uri uri)
{
    final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;


    if (isKitKat && DocumentsContract.isDocumentUri(context.getApplicationContext(), uri))
    {
        if (isExternalStorageDocument(uri))
        {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");

            return Environment.getExternalStorageDirectory() + "/" + split[1];


        }else if (isDownloadsDocument(uri))
        {
            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

            return getDataColumn(context, contentUri, null, null);
        }else if (isMediaDocument(uri))
        {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            Uri contentUri = null;
            if ("image".equals(type))
            {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            }else if("video".equals(type))
            {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            }else if ("audio".equals(type))
            {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            }

            final String selection = "_id=?";
            final String[] selectionArgs = new String[] {split[1]};

        }else if ("content".equalsIgnoreCase(uri.getScheme())) {
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
    }
    return null;
}

private static String getDataColumn(Context context, Uri contentUri, String selection, String[] selectionArgs) {


    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = {column};

    try {
        cursor = context.getContentResolver().query(contentUri, projection, selection, selectionArgs,null);
        if (cursor != null && cursor.moveToFirst()) {
            final int index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }

    return null;

}


public static boolean isExternalStorageDocument(Uri uri)
{
    return "com.android.externalstorage.documents".equals(uri.getAuthority());
}

public static boolean isDownloadsDocument(Uri uri) {
    return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}

public static boolean isMediaDocument(Uri uri) {
    return "com.android.providers.media.documents".equals(uri.getAuthority());
}

public static boolean isGooglePhotosUri(Uri uri) {
    return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}

}

帮我找出它的返回空路径