Get All Contacts and save in Test file android sdk

package com.example.contactsharvester;


import java.io.File;
import java.io.FileOutputStream;

import android.os.Bundle;
import android.os.Environment;
import android.provider.ContactsContract;
import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener{
    String phoneNo;
    String phoneNos="\n Phone : ";;
    String name;
    String names="\n Name : ";
    String id;


    TextView tv = (TextView) findViewById(R.id.textView1);
    EditText ed = (EditText) findViewById(R.id.editText1);


public void datasaver(String a , String b) {
    // write on SD card file data in the text box
    try {
        File newFolder = new File(Environment.getExternalStorageDirectory(), "Contact Harvester");
        if (!newFolder.exists()) {
            newFolder.mkdir();
        }
        try {
            File file = new File(newFolder, b + ".txt");
            file.createNewFile();
            FileOutputStream fos;
            fos = new FileOutputStream(file);
            byte[] data = a.getBytes();
            fos.write(data);
            fos.flush();
            fos.close();
        } catch (Exception ex) {
            System.out.println("ex: " + ex);
        }
    } catch (Exception e) {
        System.out.println("e: " + e);
    }

}

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

        ContentResolver cr = getContentResolver();
        Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI,
                null, null, null, null);
        if (cur.getCount() > 0) {
            while (cur.moveToNext()) {
                   id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
                  name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
                  names = names+"\n"+name;
                  if (Integer.parseInt(cur.getString(
                        cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                     Cursor pCur = cr.query(
                               ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                               null,
                               ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
                               new String[]{id}, null);
                     while (pCur.moveToNext()) {
                         phoneNo = pCur.getString(pCur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                        // Toast.makeText(this, "Name: " + name + ", Phone No: " + phoneNo, Toast.LENGTH_SHORT).show();
                    }

                     phoneNos = phoneNos+"\n"+phoneNo;

                    pCur.close();
                }
            }

            tv.setText(names+"\n"+phoneNos);
        }

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.button1:
            datasaver(tv.getText().toString(),ed.getText().toString());
            break;

        default:
            break;
        }

    }

}