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.
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