I'm a newbie in programming on Android Studio. I'm trying to create a simple application to gain basic experience. In the application, I would need to store individual inputs to a file (ideally CSV) in internal memory. First of all, I am trying to save user data - my name and phone number. The save method looks like this:
public void save(View view)
{
String fileName = "user.csv";
ContextWrapper contextWrapper = new ContextWrapper(getApplicationContext());
File directory = contextWrapper.getDir(getFilesDir().getName(), ContextWrapper.MODE_PRIVATE);
File file = new File(directory, fileName);
String data = "FirstName,LastName,PhoneNumber";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(fileName, Context.MODE_PRIVATE);
outputStream.write(data.getBytes());
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
The data seems to be saved and I'm redirected to MainActivity. Here is the method:
protected void onCreate(Bundle savedInstanceState) {
File file = new File(getFilesDir(),"user.csv");
if(!file.exists()) {
Intent intent = new Intent(this, activity_login.class);
startActivity(intent);
}
else {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv_name = findViewById(R.id.tv_name);
TextView tv_phone = findViewById(R.id.tv_phone);
BufferedReader br = null;
try {
String sCurrentLine;
br = new BufferedReader(new FileReader("user.csv"));
while ((sCurrentLine = br.readLine()) != null) {
tv_name.setText(sCurrentLine);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
No value is stored in TextView tv_name and the box is empty. Where am I making mistake?
Thank you very much for your help!
For reading data saved use this method uses, UTF_8 ENCODING
public static String readAsString(InputStream is) throws IOException {
BufferedReader reader = null;
StringBuilder sb = new StringBuilder();
try {
String line;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
reader = new BufferedReader(new InputStreamReader(is,UTF_8));
}
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} finally {
if (reader != null) {
reader.close();
}
}
return sb.toString();
}
Use this method as follows, parsing file "user.csv".
public static String readFileAsString(File file) throws IOException {
return readAsString(new FileInputStream(file));
}
Fetch string and set textView
Use as this to read file:
FileInputStream fis = new FileInputStream("your full file path");
BufferedReader bfr = new BufferedReader(new InputStreamReader(fis));
Below is the code for creating .csv file and inserting data into it.
For more look into my answer :https://stackoverflow.com/a/48643905/8448886
CODE HERE:
String csv = (Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyCsvFile.csv"); // Here csv file name is MyCsvFile.csv
//by Hiting button csv will create inside phone storage.
buttonAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
CSVWriter writer = null;
try {
writer = new CSVWriter(new FileWriter(csv));
List<String[]> data = new ArrayList<String[]>();
data.add(new String[]{"Country", "Capital"});
data.add(new String[]{"India", "New Delhi"});
data.add(new String[]{"United States", "Washington D.C"});
data.add(new String[]{"Germany", "Berlin"});
writer.writeAll(data); // data is adding to csv
writer.close();
callRead();
} catch (IOException e) {
e.printStackTrace();
}
}
});
Related
I want to choose a file using the file chooser of android, then display its content in a EditText component.
I have this method where I open the file manager and search the file in Downloads
public void btnSearch(View view){
Intent fileIntent = new Intent(Intent.ACTION_GET_CONTENT);
fileIntent.setType("*/*");
fileIntent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityForResult(Intent.createChooser(fileIntent,"Seleccione"),FILE_SELECTED_CODE);
} catch (android.content.ActivityNotFoundException ex){
System.out.println( ex.getMessage());
Toast.makeText(this,"Install a File Manager. ", Toast.LENGTH_SHORT).show();
}
}
And then I use this method to read the content of the file
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(data == null)
return;
switch (requestCode){
case FILE_SELECTED_CODE:
if(resultCode == RESULT_OK){
Uri uri = data.getData();
String ruta = uri.getPath();
File archivo = new File(ruta);
try {
BufferedReader reader = new BufferedReader(new FileReader(archivo));
String linea = "";
String texto = "";
while((linea = reader.readLine()) != null){
texto += linea;
}
EditText tbxDatos = (EditText) findViewById(R.id.compDatos);
tbxDatos.setText(texto);
} catch(Exception e){
System.out.println( e.getMessage());
}
}
break;
}
super.onActivityResult(requestCode,resultCode,data);
}
But now I am having this exception when I select the file from the File Chooser:
Exception: /document/33 (No such file or directory)
Any ideas? Thank you.
Try this example Straight from the docs!!!
private String readTextFromUri(Uri uri) throws IOException {
InputStream inputStream = getContentResolver().openInputStream(uri);
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
fileInputStream.close();
parcelFileDescriptor.close();
return stringBuilder.toString();
}
I am trying to delete a specific line from a file, but when I run this, it returns me all the files, deleted. More specific i have a favorite button at a video fragment and i want when user press it ,to write the title of video in file (already done) and when unpress it to delete it....
my.java class is:
private void writeToFile(String g,Context context) {
try {
File file=new File("/data/data/com.holomedia.holomedia/config.txt");
FileOutputStream fos = new FileOutputStream(file,true);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fos);
if (!file.exists()) {outputStreamWriter.write(g);}
outputStreamWriter.append("\n"+g +"\n");
outputStreamWriter.close();
} catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
}
private void deleteToFile(String g,Context context) {
try {
File file=new File("/data/data/com.holomedia.holomedia/files/config.txt");
FileOutputStream fos = new FileOutputStream(file);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fos);
if (file.exists()) {
BufferedReader br = new BufferedReader(new FileReader(file));
StringBuilder text = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
if (!line.equals(g) && !g.equals("\n")){
text.append(line);
text.append('\n');
}
}
br.close();
outputStreamWriter.write(text.toString());
}
outputStreamWriter.close();
} catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.favorite:
if(showingFirst==true) {
Context context = getActivity();
CharSequence text = "Added to Favorites";
int duration = Toast.LENGTH_SHORT;
item.setIcon(R.drawable.heart_off);
Toast toast = Toast.makeText(context, text, duration);
toast.show();
writeToFile(title,context);
showingFirst=false;
} else {
Context context = getActivity();
CharSequence text = "Deleted from Favorites";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
deleteToFile(title,context);
item.setIcon(R.drawable.heart_wh);
showingFirst=true;
}
break;
case R.id.home:
Intent k=new Intent(getActivity(),MainActivity.class);
Log.i(TAG, "onNavigationItemSelected: ");
startActivity(k);
break;
}
return false;
}
So, problem lies at below line of codes where you are trying to open file for Read and Write simultaneously
File file=new File("/data/data/com.holomedia.holomedia/files/config.txt");
FileOutputStream fos = new FileOutputStream(file);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fos);
if (file.exists()) {
BufferedReader br = new BufferedReader(new FileReader(file));
Instead, I would suggest you to read your file completely and then at the end you should write to the file (overwrite).
try {
File file=new File("/data/data/com.holomedia.holomedia/files/config.txt");
if (file.exists()) {
BufferedReader br = new BufferedReader(new FileReader(file));
StringBuilder text = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
if (!line.equals(g) && !g.equals("\n")){
text.append(line);
text.append('\n');
}
}
br.close();
//start writing from here
FileOutputStream fos = new FileOutputStream(file);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fos);
outputStreamWriter.write(text.toString());
outputStreamWriter.flush();
outputStreamWriter.close();
}
} catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
This line:
FileOutputStream fos = new FileOutputStream(file);
resets contents of the file (ie replaces it with empty file). I recommend you add logging and/or debug your code so you will have a better understanding of what is going on.
I am making an app where I have my school balance set and can press dedicated buttons to take away certain amounts depending on what I purchase. I am having trouble with the balance. I have a way of updating it to what I want, however after I terminate the application I want it to stay the same in a TextView. I so far was able to make it save it to a file, or at least I hope I was, with the help of a video.
How could I on opening the app read the text file and set the TextView equal to what is in the file?
submitBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String submitAmount = amountEnter.getText().toString();
balance.setText(submitAmount);
String myBalance = balance.getText().toString();
try {
FileOutputStream fou = openFileOutput("balance.txt",
MODE_WORLD_READABLE);
OutputStreamWriter osw = new OutputStreamWriter(fou);
try {
osw.write(myBalance);
osw.flush();
osw.close();
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
});
You can save it in SharedPrefs
change it to
submitBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String submitAmount = amountEnter.getText().toString();
balance.setText(submitAmount);
PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).
edit().putString("balance", submitAmount).commit();
}
});
and you can get it by
String balance=PreferenceManager.getDefaultSharedPreferences(getApplicationContext())
.getString("balance","nothing_there");
Seeing your code, i assume that you know how to read/write a file in android. If not, then see it from here . https://stackoverflow.com/questions/12421814/how-can-i-read-a-text-file-in-android/ You can try the following code. THe readfile method is from the upper link. You just have to read the particular line/string from the file at onCreate method of the activity. Get the reference of your desired TextView and then set the text to TextView like below. I hope it helps you
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
String texts = readfile();
TextView textView = findViewById(R.id.text_view);
textView.setText(text);
}
private String readfile() {
File sdcard = Environment.getExternalStorageDirectory();
File file = new File(sdcard, "file.txt");
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append('\n');
}
br.close();
} catch (IOException e) {
//You'll need to add proper error handling here
}
return text.toString();
}
My project is list of music that user can set as ringtone.
All of my music is located in raw and it works correctly and also my ringtone name is a text in raw "zeallist".
My problem is that how to put my music in asset folder.
Here is my code that play music from raw:
public ArrayList<SongInfo> getAllSong(Context context) {
ArrayList<SongInfo> listSong = new ArrayList<SongInfo>();
RingtonesSharedPreferences pref = new RingtonesSharedPreferences(
context);
Field[] fields = R.raw.class.getFields();
for (int i = 0; i < fields.length - 1; i++) {
SongInfo info = new SongInfo();
try {
String name = fields[i].getName();
if (!name.equals("ringtones")) {
info.setFileName(name + ".mp3");
info.setFavorite(pref.getString(info.getFileName()));
int audioResource = R.raw.class.getField(name).getInt(name);
info.setAudioResource(audioResource);
}
// info.setName(name);
} catch (Exception e) {
}
listSong.add(info);
}
InputStream inputStream = context.getResources().openRawResource(
R.raw.zeallist);
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
try {
String line;
int i = 0;
while ((line = reader.readLine()) != null) {
listSong.get(i).setName(line);
i++;
}
} catch (Exception e) {
// TODO: handle exception
} finally {
try {
reader.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return listSong;
}
How to change this part of my code to read them from asset and return my listsong ?
Core part I have finished.Some details you need do yourself
public ArrayList<SongInfo> getAllSong(Context context) throws IOException {
ArrayList<SongInfo> listSong = new ArrayList<SongInfo>();
RingtonesSharedPreferences pref = new RingtonesSharedPreferences(context);
String[] files = context.getAssets().list("Your songs path");
for (int i = 0; i < files.length - 1; i++) {
SongInfo info = new SongInfo();
String name = files[i];
if (!name.equals("ringtones")) {
info.setFileName(name + ".mp3");
info.setFavorite(pref.getString(info.getFileName()));
/* int audioResource = R.raw.class.getField(name).getInt(name);
info.setAudioResource(audioResource);*/ //fileName is enough to you
}
// info.setName(name);
listSong.add(info);
}
InputStream inputStream = context.getAssets().open("Your zeallist path");
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
try {
String line;
int i = 0;
while ((line = reader.readLine()) != null) {
listSong.get(i).setName(line);
i++;
}
} catch (Exception e) {
// TODO: handle exception
} finally {
try {
reader.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return listSong;
}
When you want to play corresponding music, you could do like this
public void play(MediaPlayer mediaPlayer, Context context, String musicName) throws IOException {
AssetFileDescriptor assetFileDescriptor = context.getAssets().openFd(musicName);
mediaPlayer.setDataSource(assetFileDescriptor.getFileDescriptor(),
assetFileDescriptor.getStartOffset(),
assetFileDescriptor.getLength());
mediaPlayer.prepare();
mediaPlayer.start();
}
Hope this will solve your problem .
Right click on res folder and Create new folder called raw. Now copy paste few .MP3 files inside it. Check those links for better understanding.
link1
link2
From Assest folder
public void playBeep() {
try {
if (mp.isPlaying()) {
mp.stop();
mp.release();
mp = new MediaPlayer();
}
AssetFileDescriptor descriptor = getAssets().openFd("mysong.mp3");
mp.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
descriptor.close();
mp.prepare();
mp.setVolume(1f, 1f);
mp.setLooping(true);
mp.start();
} catch (Exception e) {
e.printStackTrace();
}
}
You can read file from asset using AssetManager
AssetManager assetManager = getAssets();
String[] files = assetManager.list("");
Note that this file is String array. So don't forget to initialize new file for each element of the array before iterating over it.
I just want to ask about my code whether it's right, because I can't load the text in my name.txt file.
Also I just want to know how to save the input text in my name.txt file.
load.setOnClickListener(new
View.OnClickListener() {
#Override
public void onClick
(View arg0) {
try{
StringBuffer sb=new StringBuffer();
FileInputStream fis=con.openFileInput("name.txt");
DataInputStream dis=new DataInputStream(fis);
String text=null;
while((text=dis.readLine())!=null)
sb.append(text+"\n");
dis.close();
et1.setText(sb.toString());
}catch
(IOException e){
Toast.makeText(con, "Could not find", Toast.LENGTH_LONG).show();
}
}
});
If you want to write data to file
static protected void writeToFile(String strToWrite)
{
try
{
BufferedWriter out = new BufferedWriter(new FileWriter("name.txt", true));
out.write(strToWrite);
out.close();
}
catch (IOException e) { e.printStackTrace();}
}
The code you have written is to read data from an existing file not to write in the file.
try
{
File file1 = new File(Environment.getExternalStorageDirectory() + "/dir/", "filename.extension");
FileWriter fw1 = new FileWriter(file1.getAbsoluteFile());
BufferedWriter bw1 = new BufferedWriter(fw1);
bw1.write("Stringtowritetofile");
bw1.close();
}