How to Read/Write String from a File in Android

0 votes

I want to save a file to the internal storage by getting the text inputted from EditText. Then I want the same file to return the inputted text in String form and save it to another String which is to be used later.

Here's the code:

package com.omm.easybalancerecharge;


import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final EditText num = (EditText) findViewById(R.id.sNum);
        Button ch = (Button) findViewById(R.id.rButton);
        TelephonyManager operator = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        String opname = operator.getNetworkOperatorName();
        TextView status = (TextView) findViewById(R.id.setStatus);
        final EditText ID = (EditText) findViewById(R.id.IQID);
        Button save = (Button) findViewById(R.id.sButton);

        final String myID = ""; //When Reading The File Back, I Need To Store It In This String For Later Use
save.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                //Get Text From EditText "ID" And Save It To Internal Memory
            }
        });
        if (opname.contentEquals("zain SA")) {
            status.setText("Your Network Is: " + opname);
        } else {
            status.setText("No Network");
        }
        ch.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                //Read From The Saved File Here And Append It To String "myID"


                String hash = Uri.encode("#");
                Intent intent = new Intent(Intent.ACTION_CALL);
                intent.setData(Uri.parse("tel:*141*" + /*Use The String With Data Retrieved Here*/ num.getText()
                        + hash));
                startActivity(intent);
            }
        });
    }
I have included comments to help you further analyze my points as to where I want the operations to be done/variables to be used.
Oct 3, 2018 in Java by Sushmita
• 6,890 points
2,131 views

1 answer to this question.

0 votes

Writing a File in android:

private void writeToFile(String data,Context context) {
    try {
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("config.txt", Context.MODE_PRIVATE));
        outputStreamWriter.write(data);
        outputStreamWriter.close();
    }
    catch (IOException e) {
        Log.e("Exception", "File write failed: " + e.toString());
    } 
}


Reading a File in android:

private String readFromFile(Context context) {

    String ret = "";

    try {
        InputStream inputStream = context.openFileInput("config.txt");

        if ( inputStream != null ) {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();

            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append(receiveString);
            }

            inputStream.close();
            ret = stringBuilder.toString();
        }
    }
catch (FileNotFoundException e) {
        Log.e("login activity", "File not found: " + e.toString());
    } catch (IOException e) {
        Log.e("login activity", "Can not read file: " + e.toString());
    }

    return ret;
}
answered Oct 3, 2018 by sharth
• 3,370 points

Related Questions In Java

0 votes
3 answers

How to read a Text File in Java?

You can use readAllLines and the join method to ...READ MORE

answered Jul 27, 2018 in Java by samarth295
• 2,190 points
275 views
0 votes
0 answers

Write a program that uses a while loop to read 10 integer numbers from file

Write a program that uses a while ...READ MORE

Apr 15 in Java by MIH
• 160 points
132 views
0 votes
1 answer

how to read csv file form sftp connection and store into string object in java code and convert into json.....post it using rest api

Hey, @Pooja, Before starting with anything you should ...READ MORE

answered May 12 in Java by Roshni
• 1,130 points
172 views
0 votes
1 answer

How to run a .java file from command line passing arguments in Maven?

Hello @kartik, You could run: mvn exec:exec -Dexec.args="arg1". This will ...READ MORE

answered Jun 3 in Java by Niroj
• 33,120 points
164 views
0 votes
1 answer

Write files to external public storage in Android

MediaStore has not discovered your newly-created files yet. ...READ MORE

answered Mar 1, 2019 in Java by developer_1
• 3,300 points
525 views
0 votes
2 answers

How can I get the filenames of all files in a folder which may or may not contain duplicates

List<String> results = new ArrayList<String>(); File[] files = ...READ MORE

answered Sep 12, 2018 in Java by Sushmita
• 6,890 points
705 views
0 votes
2 answers

Store String inside a File using Java

We can use Apache Commons IO. It ...READ MORE

answered Jul 20, 2018 in Java by Sushmita
• 6,890 points
81 views
0 votes
2 answers

How to read a text file in Java?

You can use Scanner class to read ...READ MORE

answered Aug 9, 2018 in Java by Parth
• 4,630 points
115 views
0 votes
2 answers

How can I convert a String variable to a primitive int in Java

 Here are two ways illustrating this: Integer x ...READ MORE

answered Aug 20, 2019 in Java by Sirajul
• 54,070 points
417 views
0 votes
3 answers

How to reverse a string in java?

public static String reverse(String s) { ...READ MORE

answered Aug 16, 2018 in Java by samarth295
• 2,190 points
179 views