CODEWITHSUNDEEP
javaandroidfilefile-io
Sumit M Asok
Sumit M Asok

Reputation: 2950

Writing a file to sdcard

I'm trying to write a file from an Http post reply to a file on the sdcard. Everything works fine until the byte array of data is retrieved.

I've tried setting WRITE_EXTERNAL_STORAGE permission in the manifest and tried many different combinations of tutorials I found on the net.

All I could find was using the openFileOutput("",MODE_WORLD_READABLE) method, of the activity but how my app writes file is by using a thread. Specifically, a thread is invoked from another thread when a file has to be written, so giving an activity object didn't work even though I tried it.

The app has come a long way and I cannot change how the app is currently written.

Please, someone help me?

CODE:

File file = new File(bgdmanip.savLocation);
FileOutputStream filecon = null;
filecon = new FileOutputStream(file);

byte[] myByte;
myByte = Base64Coder.decode(seReply);

bos.write(myByte);
filecon.write(myByte);
myvals = x * 11024;

bgdmanip.savLocation holds the whole files path. seReply is a string reply from HttpPost response. The second set of code is looped with reference to x. The file is created but remains 0 bytes.

Upvotes: 21

Views: 54155

Answers (3)

gtangil
gtangil

Reputation: 747

Here is a sample:

// Log used as debug
File log = new File(Environment.getExternalStorageDirectory(), "Log.txt");
try {
    out = new BufferedWriter(new FileWriter(log.getAbsolutePath(), false));
    out.write(new Date().toString());
    out.write(" : \n");
} catch (Exception e) {
    Log.e(TAG, "Error opening Log.", e);
}

Upvotes: 3

Pir Fahim Shah
Pir Fahim Shah

Reputation: 10623

//------------------------------WRITING DATA TO THE FILE ---------------------------------      

btnWriteSDFile.setOnClickListener(new OnClickListener() 
    {
    public void onClick(View v)
    {       

        try {
            File myFile = new File("/sdcard/mysdfile.txt");
            myFile.createNewFile();
            FileOutputStream fOut = new FileOutputStream(myFile);
            OutputStreamWriter myOutWriter =new OutputStreamWriter(fOut);
            myOutWriter.append(txtData.getText());
            myOutWriter.close();
            fOut.close();
            Toast.makeText(v.getContext(),"Done writing SD 'mysdfile.txt'", Toast.LENGTH_SHORT).show();
            txtData.setText("");
        } 
        catch (Exception e) 
        {
            Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
        }
    }


    }); 

//---------------------------READING DATA FROM THE FILE PLACED IN SDCARD-------------------//       
        btnReadSDFile.setOnClickListener(new OnClickListener()
        {

        public void onClick(View v) 
        {

        try {

            File myFile = new File("/sdcard/mysdfile.txt");
            FileInputStream fIn = new FileInputStream(myFile);
            BufferedReader myReader = new BufferedReader(new InputStreamReader(fIn));
            String aDataRow = "";
            String aBuffer = "";
            while ((aDataRow = myReader.readLine()) != null) 
            {
                aBuffer += aDataRow ;
            }
            txtData.setText(aBuffer);
            myReader.close();
            Toast.makeText(v.getContext(),"Done reading SD 'mysdfile.txt'",Toast.LENGTH_SHORT).show();
        } 
        catch (Exception e)
        {
            Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
        }
        }
        });

ALONG WITH THIS ALSO WRITE THIS PERMISSION IN Android.Manifest

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Upvotes: 29

Erich Douglass
Erich Douglass

Reputation: 51992

The openFileOutput() method writes data to your application's private data area (not the SD card), so that's probably not what you want. You should be able to call Environment.getExternalStorageDirectory() to get the root path to the SD card and use that to create a FileOutputStream. From there, just use the standard java.io routines.

Upvotes: 22

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