如何上传特定部分的文件，并将特定于某个部分的文件从我的网络服务器下载到我的Android应用程序？每当我点击显示服务器上的文件时，它都会显示所有文件。我希望它只显示某个部分的特定文件。
这是我的代码：
上传文件
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_professor_upload_file_to_server);
button = (ImageButton) findViewById(R.id.imageButton);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
if(ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},100);
return;
}
}
enable_button();
}
private void enable_button() {
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new MaterialFilePicker()
.withActivity(ProfessorUploadFileToServerActivity.this)
.withRequestCode(10)
.start();
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if(requestCode == 100 && (grantResults[0] == PackageManager.PERMISSION_GRANTED)){
enable_button();
}else {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},100);
}
}
}
@Override
public void onBackPressed(){
Intent intent = new Intent(ProfessorUploadFileToServerActivity.this,ProfessorMainMenuActivity.class);
ProfessorUploadFileToServerActivity.this.startActivity(intent);
finish();
}
ProgressDialog progress;
@Override
protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
if(requestCode == 10 && resultCode == RESULT_OK){
progress = new ProgressDialog(ProfessorUploadFileToServerActivity.this);
progress.setTitle("Uploading");
progress.setMessage("Please wait...");
progress.show();
Thread t = new Thread(new Runnable() {
@Override
public void run() {
File f = new File(data.getStringExtra(FilePickerActivity.RESULT_FILE_PATH));
String content_type = getMimeType(f.getPath());
String file_path = f.getAbsolutePath();
OkHttpClient client = new OkHttpClient();
RequestBody file_body = RequestBody.create(MediaType.parse(content_type),f);
RequestBody request_body = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("type",content_type)
.addFormDataPart("uploaded_file",file_path.substring(file_path.lastIndexOf("/")+1), file_body)
.build();
Request request = new Request.Builder()
.url("https://orwell-systems.000webhostapp.com/UploadToServer.php")
.post(request_body)
.build();
try {
Response response = client.newCall(request).execute();
if(!response.isSuccessful()){
throw new IOException("Error : "+response);
}
progress.dismiss();
} catch (IOException e) {
e.printStackTrace();
}
}
});
t.start();
}
}
private String getMimeType(String path) {
String extension = MimeTypeMap.getFileExtensionFromUrl(path);
return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
}
我的下载文件
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_student_download_file);
permission_check();
}
private void permission_check() {
if(ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);
return;
}
}
initialize();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if(requestCode == 100 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
initialize();
}else {
permission_check();
}
}
@Override
public void onBackPressed() {
Intent intent = new Intent(StudentDownloadFileActivity.this,StudentMainMenuActivity.class);
StudentDownloadFileActivity.this.startActivity(intent);
finish();
}
private void initialize() {
button = (Button) findViewById(R.id.button);
listView = (ListView) findViewById(R.id.listView);
arrayAdapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,files_on_server);
listView.setAdapter(arrayAdapter);
handler = new Handler();
progressDialog = new ProgressDialog(this);
progressDialog.setTitle("Downloading...");
progressDialog.setMax(100);
progressDialog.setCancelable(false);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Thread t = new Thread(new Runnable() {
@Override
public void run() {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url("https://orwell-systems.000webhostapp.com/DownloadFromServer.php?list_files").build();
Response response = null;
try {
response = client.newCall(request).execute();
JSONArray array = new JSONArray(response.body().string());
for (int i = 0; i <array.length(); i++){
String file_name = array.getString(i);
if(files_on_server.indexOf(file_name) == -1)
files_on_server.add(file_name);
}
handler.post(new Runnable() {
@Override
public void run() {
arrayAdapter.notifyDataSetChanged();
}
});
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
});
t.start();
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
selected_file = ((TextView)view).getText().toString();
Thread t = new Thread(new Runnable() {
@Override
public void run() {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url("https://orwell-systems.000webhostapp.com//uploads/" + selected_file).build();
Response response = null;
try {
response = client.newCall(request).execute();
float file_size = response.body().contentLength();
BufferedInputStream inputStream = new BufferedInputStream(response.body().byteStream());
OutputStream stream = new FileOutputStream(Environment.getExternalStorageDirectory()+"/Download/"+selected_file);
byte[] data = new byte[8192];
float total = 0;
int read_bytes=0;
handler.post(new Runnable() {
@Override
public void run() {
progressDialog.show();
}
});
while ( (read_bytes = inputStream.read(data)) != -1 ){
total = total + read_bytes;
stream.write( data, 0, read_bytes);
progressDialog.setProgress((int) ((total / file_size)*100));
}
progressDialog.dismiss();
stream.flush();
stream.close();
response.body().close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
t.start();
}
});
}
提前谢谢