i created a file and when i run the program, the data is been written in to the file but when i run the program again the new data over write on old data.
i need once the program is running and gathers data, these data are writable into the file in cascade next each other without overwriting on previous data in file.
this code running successful but when i run the program again the over writing happens which i don need that, i need to save previous data in side the file and write the new data next it and soon.
after edit this code its looks like:
public class MainActivity extends Activity {
File file;
File sdCard;
FileOutputStream fos;
OutputStreamWriter myOutWriter;
String FileName = "Output3.txt";
String eol;
OutputStream fos1;
FileWriter fw ;
BufferedWriter writer;
BufferedWriter bw ;
PrintWriter out;
EditText txtData;
Button btnWriteSDFile;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sdCard =getExternalFilesDir(null);
file = new File(sdCard,FileName);
txtData = (EditText) findViewById(R.id.editText1);
btnWriteSDFile = (Button) findViewById(R.id.button1);
btnWriteSDFile.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
try {
fos = new FileOutputStream(file);
myOutWriter =new OutputStreamWriter(fos);
eol = System.getProperty("line.separator");
writer = new BufferedWriter(myOutWriter);
writer.append(txtData.getText() + eol);// write this text.
writer.flush();
fos.close();
Toast.makeText(v.getContext(),"Done writing SD 'Output.txt'", Toast.LENGTH_SHORT).show();
txtData.setText("");
} catch (Exception e) {
// e.printStackTrace();
Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
}
finally{
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
});
}
please,can any one answer me?
Instead of using OutputStreamWriter use Filewriter FileWriter fileWritter = new FileWriter(file,true); when u pass true it appends the contents.try this
FileWriter myOutWriter = new FileWriter(file.getName(),true);
eol = System.getProperty("line.separator");
writer = new BufferedWriter(myOutWriter);
writer.write(txtData.getText() + eol);// write this text.
writer.close();
fos.close();
Change this line:
fos = new FileOutputStream(file);
To:
fos = new FileOutputStream(file, true);
This opens the file so that data can be appended.
JavaDocs for FileOutputStream
use
FileWriter writer = new FileWriter("yourfilename", true);
second parameter should be passed as true which will append data instead of overwriting
try {
File myFile = new File(Environment.getExternalStorageDirectory() + File.separator + "test.txt");
// this changed bye fos = new FileOutputStream(myFile) to
fos = new FileOutputStream(myFile,true);
//FileWriter writer = new FileWriter("yourfilename", true);
myOutWriter = new OutputStreamWriter(fos);
eol = System.getProperty("line.separator");
writer = new BufferedWriter(myOutWriter);
writer.append("\n");
writer.append(txtData.getText() + eol);// write this text.
writer.flush();
fos.close();
Toast.makeText(v.getContext(),
"Done writing SD 'Output.txt'", Toast.LENGTH_SHORT)
.show();
txtData.setText("");
} catch (Exception e) {
// e.printStackTrace();
Toast.makeText(v.getContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
} finally {
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Enjoye i have tested it is work for me.
Related
I want to write a .txt file to the phone so the user can access from file storage
This is what I have so far, but I found out it was only available to my app.
path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS);
public void Print() {
String print = "text"
printstring(print);
}
public void printstring(String s) {
try {
File file = new File(path, "fileName.txt");
FileOutputStream fileOutputStream = new FileOutputStream(file);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);
BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);
bufferedWriter.write(s);
bufferedWriter.close();
outputStreamWriter.close();
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText( MainActivity.getAppContext() , "Toast", 1000).show();
}
}
}
for those that need the answer, I figured it out.
public void printstring(String print) {
try {
File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS), "filename.txt");
FileOutputStream fileOutputStream = new FileOutputStream(file);
PrintWriter printWriter = new PrintWriter(fileOutputStream);
printWriter.write(print);
printWriter.close();
fileOutputStream.close();
Toast.makeText(MainActivity.getAppContext(), "save successful", Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(MainActivity.getAppContext(), "Toast", Toast.LENGTH_LONG).show();
}
then I need the following in the Manifest
<application android:requestLegacyExternalStorage="true" ... </application>
on top of the user permissions
How to append data one by one in existing file? Am using following code.. Append the data row order in file..How to solve this?
private String SaveText() {
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath()+File.separator+"GPS");
dir.mkdirs();
String fname = "gps.txt";
File file = new File (dir, fname);
FileOutputStream fos;
try {
fos = new FileOutputStream(file,true);
OutputStreamWriter out=new OutputStreamWriter(fos);
out.write(value1);
out.close();
fos.close();
Toast.makeText(getApplicationContext(), "Saved lat,long", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
return dir.getAbsolutePath();
}
Try this code
try{
OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file,true), "UTF-8");
BufferedWriter fbw = new BufferedWriter(writer);
fbw.write(value1);
fbw.newLine();
fbw.close();
Toast.makeText(getApplicationContext(), "Saved lat,long", Toast.LENGTH_SHORT).show();
}
catch (Exception e) {
e.printStackTrace();
}
Copy and paste this code.
public void SaveText(String sFileName, String sBody){
try
{
File root = new File(Environment.getExternalStorageDirectory(), "Notes");
if (!root.exists()) {
root.mkdirs();
}
File gpxfile = new File(root, sFileName);
FileWriter writer = new FileWriter(gpxfile);
writer.append(sBody);
writer.flush();
writer.close();
Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show();
}
catch(IOException e)
{
e.printStackTrace();
importError = e.getMessage();
iError();
}}
In JAVA 7 you can try:
try {
Files.write(Paths.get(dir+File.separator+fname), latLng.getBytes(), StandardOpenOption.APPEND);
} catch (IOException e) {
e.printStackTrace();
}
checkout Beautiful explanation :here
Could someone look at this snippet of code please and let me know what I'm doing wrong? It's a simple function that takes a string as parameter which it uses as a file name, adding ".txt" to the end of it.
The function checks if the file exists, creating it if it doesn't and then writes two lines of text to the file. Everything appears to be working and the file is created successfully on the sd card. However, after everything is done, the file is empty (and has a size of 0 bytes).
I suspect it's something obvious that I'm overlooking.
public void writeFile(String fileName) {
String myPath = new File(Environment.getExternalStorageDirectory(), "SubFolderName");
myPath.mkdirs();
File file = new File(myPath, fileName+".txt");
try {
if (!file.exists()) {
if (!file.createNewFile()) {
Toast.makeText(this, "Error Creating File", Toast.LENGTH_LONG).show();
return;
}
}
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_PRIVATE));
writer.append("First line").append('\n');
writer.append("Second line").append('\n');
writer.close();
}
catch (IOException e) {
// Do whatever
}
}
Hi I will show you the full code I use, works perfect.
I don't use
new OutputStreamWriter()
i use
new BufferedWriter()
here is my Snippet
public void writeToFile(Context context, String fileName, String data) {
Writer mwriter;
File root = Environment.getExternalStorageDirectory();
File dir = new File(root.getAbsolutePath() + File.separator + "myFolder");
if (!dir.isDirectory()) {
dir.mkdir();
}
try {
if (!dir.isDirectory()) {
throw new IOException(
"Unable to create directory myFolder. SD card mounted?");
}
File outputFile = new File(dir, fileName);
mwriter = new BufferedWriter(new FileWriter(outputFile));
mwriter.write(data); // DATA WRITE TO FILE
Toast.makeText(context.getApplicationContext(),
"successfully saved to: " + outputFile.getAbsolutePath(), Toast.LENGTH_LONG).show();
mwriter.close();
} catch (IOException e) {
Log.w("write log", e.getMessage(), e);
Toast.makeText(context, e.getMessage() + " Unable to write to external storage.",Toast.LENGTH_LONG).show();
}
}
-- Original Code --
That one took a while to find out. The javadocs
here brought me on the right track.
It says:
Parameters
name The name of the file to open; can not contain path separators.
mode Operating mode. Use 0 or MODE_PRIVATE for the default operation, MODE_APPEND to append to an existing file, MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE to control permissions.
The file is created, if it does not exist, but it is created in the private app space. You create the file somewhere on the sd card using File.createNewFile() but when you do context.openFileOutput() it creates always a private file in the private App space.
EDIT: Here's my code. I've expanded your method by writing and reading the lines and print what I got to logcat.
<pre>
public void writeFile(String fileName) {
try {
OutputStreamWriter writer = new OutputStreamWriter(
getContext().openFileOutput(fileName + ".txt", Context.MODE_PRIVATE));
writer.append("First line").append('\n');
writer.append("Second line").append('\n');
writer.close();
}
catch (IOException e) {
Log.e("STACKOVERFLOW", e.getMessage(), e);
return;
// Do whatever
}
// Now read the file
try {
BufferedReader is = new BufferedReader(
new InputStreamReader(
getContext().openFileInput(fileName + ".txt")));
for(String line = is.readLine(); line != null; line = is.readLine())
Log.d("STACKOVERFLOW", line);
is.close();
} catch (IOException e) {
Log.e("STACKOVERFLOW", e.getMessage(), e);
return;
// Do whatever
}
}
Change the mode from Context.MODE_PRIVATE to Context.MODE_APPEND in openFileOutput()
MODE_APPEND
MODE_PRIVATE
Instead of
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_PRIVATE));
Use
OutputStreamWriter writer = new OutputStreamWriter(openFileOutput(file.getName(), Context.MODE_APPEND));
UPDATE :
1.
FileOutputStream osr = new FileOutputStream(file.getName(), true); // this will set append flag to true
OutputStreamWriter writer = new OutputStreamWriter(osr);
BufferedWriter fbw = new BufferedWriter(writer);
fbw.write("First line");
fbw.newLine();
fbw.write("Second line");
fbw.newLine();
fbw.close();
Or 2.
private void writeFileToInternalStorage() {
FileOutputStream osr = new FileOutputStream(file.getName(), true); // this will set append flag to true
String eol = System.getProperty("line.separator");
BufferedWriter fbw = null;
try {
OutputStreamWriter writer = new OutputStreamWriter(osr);
fbw = new BufferedWriter(writer);
fbw.write("First line" + eol);
fbw.write("Second line" + eol);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fbw != null) {
try {
fbw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
I use the following code to save password in a txt file:
String FILE_NAME="lol.txt";
public void writeData(String password){
FileOutputStream fOut = null;
OutputStreamWriter osw = null;
try{
fOut = openFileOutput(FILE_NAME, Context.MODE_PRIVATE);
osw = new OutputStreamWriter(fOut);
osw.write(password);
osw.close();
fOut.close();
}catch(Exception e){
e.printStackTrace(System.err);
}
}
but When I retrive the password that I just Saved using toast its appears OK, but when I Log it into my LogCat I got Something like the following:
gana???????????????????????????????????? .... and more four lines.
I save the word gana into my file using save method which work as OnClikc method that set value of EditText as password as below:
public void save(View v){
password= txt.getText().toString();
writeData(password);
}
any Way or clue how can I solve this problem?
regards
Use below code to reading file
byte[] b = null;
try
{
//read file data...
FileInputStream myFile = openFileInput("lol.txt");
b = new byte[1024];
myFile.read(b);
Log.i("Pass", "File data is: " + new String(b).trim());
myFile.close();
}
catch (IOException e)
{
}
only difference with your code is that i am using new String(b).trim() to remove blank space.
with the below piece of code, I'm able to create a new file called output.txt and i'm able to write data. Problem is this file gets recreated once i close my app and then open my app again. As because i create this in onCreate().
But i would like to have the file created only once and then i would like to append the data there after.
private File outputFile = null;
FileOutputStream fOut = null;
OutputStreamWriter osw = null;
#Override
public void onCreate(Bundle savedInstanceState) {
....
if(outputFile == null)
outputFile = new File("/storage/new/output.txt");
if(osr==null){
try {
osr = new FileOutputStream(outputFile);
out = new DataOutputStream(osr);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
.....
try {
out.writeBytes(data);
out.flush();
//out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Try setting the append flag to true when constructing your FileOutputStream
osr = new FileOutputStream(outputFile, true);
Try,
FileOutputStream fileOut = openFileOutput(outputFile, MODE_APPEND);
OutputStreamWriter osw = new OutputStreamWriter(fileOut);
osw.writeBytes(data);
osw.flush();