deleting file content once data sent to server android

Question

I have implemented a kind of cache in which when app is not connected with internet I write the data on file, but once it gets internet and send all the data to server, I want to remove all the content from the file. I open that file in append mode and it seems like it is not removing content from file. Here is my code....

  if (!(isNetworkAvailable())) {
                    try {

                        firstConnect = true;
                        outputStream = ctx.openFileOutput("cache.txt", Context.MODE_APPEND);

                        outputStream.write(new String().getBytes());
                        outputStream.write(data.getBytes());
                        outputStream.write("new_data".getBytes());
                        outputStream.flush();
                        outputStream.close();
                        Log.d(TAG, "OCIUFNF");
                    } catch (IOException exception) {
                        exception.printStackTrace();
                    }

This code is executed everytime I collect data and there is no connectivity.

Here is my broadcast reciever that triggers on connectivity change

class NetworkReceiver extends BroadcastReceiver {
    public void onReceive(Context c, Intent intent) {

        String action  = intent.getAction();
        connectionManager = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo net = connectionManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        if(action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
                sendFileData();
        }

    }
}

protected void sendFileData() {
    StringBuilder total = new StringBuilder();
    if(firstConnect) {
        try {
            FileInputStream inputStream = service.openFileInput("cache.txt");
            BufferedReader r = new BufferedReader(new InputStreamReader(inputStream));
            String line;
            while ((line = r.readLine()) != null) {
                total.append(line);
            }
            r.close();
            inputStream.close();
        } catch (IOException exception) {
            exception.printStackTrace();
        }
        String[] parts = total.toString().split("new_data");
        for (int i = 1; i < parts.length; i++) {
            if(!(parts[i].toString().equals(parts[i-1]))) {
                Intent cacheIntent = new Intent(ctx, serviceRequest.class);
                cacheIntent.putExtra("Data", parts[i]);
                ctx.startService(cacheIntent);
            }
        }
        try {
            FileOutputStream writer = new FileOutputStream("cache.txt");
            writer.write(new String().getBytes());
            writer.close();
            Log.d(TAG, "ddjdbdjhd");
            //outputStream.write(new String().getBytes());
        }catch (IOException exception){
            exception.printStackTrace();
        }
        firstConnect = false;
    }

}

but it is not working, any idea where I am doing wrong or good solution thanks

What is the error you get? Or is it like no error but no output? — Vilas, Jan 12 '15 at 06:09

score 1 · Answer 1 · edited May 23 '17 at 12:27

1

You can delete the entire file once you have uploaded the file contents successfully. You can delete the file as follows.

File file = new File(selectedFilePath); boolean deleted = file.delete();

For more info, refer this thread.

How to delete a file from SD card?

If you want to delete the content of the file and not actual file, you can do as follows.

new RandomAccessFile(fileName).setLength(0);

OR

FileWriter (path, false);

The false will tell the writer to truncate the file instead of appending to it.

edited May 23 '17 at 12:27

Community

1
1

answered Jan 12 '15 at 06:17

Vilas

1,695
1
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13

but it throws the exception of java.io.FileNotFoundException: cache.txt: open failed: EROFS (Read-only file system) – user3290805 Jan 12 '15 at 09:25
what you tried to do? delete or remove content? can you post entire exception log? – Vilas Jan 12 '15 at 09:27

score 1 · Accepted Answer · answered Jan 12 '15 at 16:36

You have created the file using FileOutputStream with current context. So you can use the same way to delete the created file. for example in you case, it should be like this

 String[] parts = total.toString().split("new_data");
    for (int i = 1; i < parts.length; i++) {
        if(!(parts[i].toString().equals(parts[i-1]))) {
            Intent cacheIntent = new Intent(ctx, serviceRequest.class);
            cacheIntent.putExtra("Data", parts[i]);
            ctx.startService(cacheIntent);
        }
    }

       c**tx.deleteFile("cache.txt");**
        Log.d(TAG, "ddjdbdjhd");
        //outputStream.write(new String().getBytes());

    firstConnect = false;

this will delete and you can create new file everytime you add new data, so handle that situation.

deleting file content once data sent to server android

2 Answers2