Writing and reading a file from an SD card in Android

Question

I am making an Android application that will write a text file to an SD card from a text field after clicking a button and after receiving an SMS message containing the same text.

How to save a text file to an SD card and read from this text file after receiving SMS? This is the code that I still have:

import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.os.Environment; import android.telephony.gsm.SmsMessage; import android.widget.Toast; import android.media.MediaPlayer; public class IncomingSmsCaptureApp extends BroadcastReceiver { MediaPlayer mp1; @Override public void onReceive(Context context, Intent intent) { File sdcard = Environment.getExternalStorageDirectory(); //Get the text file File file = new File(sdcard,"Notes\file.txt"); //Read text from file String text = new String(); try { BufferedReader br = new BufferedReader(new FileReader(file)); String line; while ((line = br.readLine()) != null) { } } catch (IOException e) { //You'll need to add proper error handling here } //---get the SMS message passed in--- Bundle bundle = intent.getExtras(); SmsMessage[] msgs = null; String str = ""; String Message = ""; if (bundle != null) { //---retrieve the SMS message received--- Object[] pdus = (Object[]) bundle.get("pdus"); msgs = new SmsMessage[pdus.length]; for (int i=0; i<msgs.length; i++){ msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]); str += "SMS from " + msgs[i].getOriginatingAddress(); str += " :"; str += msgs[i].getMessageBody().toString(); str += "\n"; Message = msgs[i].getMessageBody().toString(); } //---display the new SMS message--- Toast.makeText(context, str, Toast.LENGTH_SHORT).show(); if (Message.equals("alarm")) { //Play alarm sound mp1 = MediaPlayer.create(context, R.raw.alarm); mp1.start(); } else { if (Message.equals(text)) { //Perform action } } } } } 

Answer 1

The following code will help you write text to a file and save it in the root directory

First get the text from your text box

 String text = myTextView.getText().toString(); 

Then write the following instructions for writing to a text file

 File logFile = new File(Environment.getExternalStorageDirectory().toString(), "myFile.txt"); if(!logFile.exists()) { logFile.createNewFile(); } BufferedWriter output = new BufferedWriter(new FileWriter(logFile)); output.write(text); output.close(); 

And your file will be saved in the root directory

Remember to add WRITE_EXTERNAL_STORAGE to your manifest

Answer 2

Here is some basic code that writes text from a TextView to a file on your SD card.

 File myFile = new File(Environment.getExternalStorageDirectory().toString(), "myFile.txt"); myFile.createNewFile(); FileOutputStream fOut = new FileOutputStream(myFile); OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut); myOutWriter.append(txtData.getText()); myOutWriter.close(); fOut.close(); 

Hope this helps!