as you provide me the code i make two class and run it but it fc..my error is also give below..pls take a look..

CsvSender class is


package contactlist.pkg;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.ContactsContract;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class CsvSender extends Activity {

    private boolean csv_status = false;

    @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            createCSV();
            if(csv_status)
              exportCSV();
        }
    private void createCSV() {
         CSVWriter writer = null;
         try {
			writer = new CSVWriter(new FileWriter(Environment.getExternalStorageDirectory().getAbsolutePath() + "/my_test_contact.csv"));
		} catch (IOException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
         String displayName;
         String number;
         long _id;
         String columns[] = new String[]{ ContactsContract.Contacts._ID,
                    ContactsContract.Contacts.DISPLAY_NAME };
         writer.writeColumnNames(); // Write column header
         Cursor cursor = getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
                    columns,
                    null,
                    null,
                    ContactsContract.Data.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
         startManagingCursor(cursor);
        if(cursor.moveToFirst()) {
            do {
                _id = Long.parseLong(cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID)));
                displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)).trim();
                number = getPrimaryNumber(_id);
                writer.writeNext((displayName + "/" + number).split("/"));
            } while(cursor.moveToNext());
            csv_status = true;
        } else {
            csv_status = false;
        }
        try {
             if(writer != null)
                 writer.close();
         } catch (IOException e) {
            Log.w("Test", e.toString());
         }

    }// Method  close.


    private void exportCSV() {
        if(csv_status == true) {
            //CSV file is created so we need to Export that ...
             final File CSVFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/my_test_contact.csv");
             //Log.i("SEND EMAIL TESTING", "Email sending");
             Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
             emailIntent.setType("text/csv");
             emailIntent .putExtra(android.content.Intent.EXTRA_SUBJECT, "Test contacts ");
             emailIntent .putExtra(android.content.Intent.EXTRA_TEXT, "\n\nAdroid developer\n Pankaj");
             emailIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("file://" + CSVFile.getAbsolutePath()));
             emailIntent.setType("message/rfc822"); // Shows all application that supports SEND activity
             try {
                 startActivity(Intent.createChooser(emailIntent, "Send mail..."));
             } catch (android.content.ActivityNotFoundException ex) {
                 Toast.makeText(getApplicationContext(), "Email client : " + ex.toString(), Toast.LENGTH_SHORT);
             }
         } else {
             Toast.makeText(getApplicationContext(), "Information not available to create CSV.", Toast.LENGTH_SHORT).show();
         }
    }
        /**
         * Get primary Number of requested  id.
         *
         * @return string value of primary number.
         */
        private String getPrimaryNumber(long _id) {
            String primaryNumber = null;
            try {
                Cursor cursor = getContentResolver().query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                        new String[]{Phone.NUMBER, Phone.TYPE},
                        ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = "+ _id, // We need to add more selection for phone type
                        null,
                        null);
                if(cursor != null || cursor.getCount() > 0) {
                    while(cursor.moveToNext()){
                        switch(cursor.getInt(cursor.getColumnIndex(Phone.TYPE))){
                            case Phone.TYPE_MOBILE :
                                primaryNumber = cursor.getString(cursor.getColumnIndex(Phone.NUMBER));
                                break;
                            case Phone.TYPE_HOME :
                                primaryNumber = cursor.getString(cursor.getColumnIndex(Phone.NUMBER));
                                break;
                            case Phone.TYPE_WORK :
                                primaryNumber = cursor.getString(cursor.getColumnIndex(Phone.NUMBER));
                                break;
                            case Phone.TYPE_OTHER :
                        }
                        if(primaryNumber != null)
                            break;
                    }
                }

				if(!cursor.isClosed() || cursor != null) {
                    cursor.deactivate();
                    cursor.close();
                }
            }  finally {


            }
            return primaryNumber;
        }
}


and CSVWriter class is




package contactlist.pkg;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;

public class CSVWriter {

    private PrintWriter pw;
    private char separator;
    private char quotechar;
    private char escapechar;
    private String lineEnd;

    /** The character used for escaping quotes. */
    public static final char DEFAULT_ESCAPE_CHARACTER = '"';

    /** The default separator to use if none is supplied to the constructor. */
    public static final char DEFAULT_SEPARATOR = ',';

    /**
     * The default quote character to use if none is supplied to the
     * constructor.
     */
    public static final char DEFAULT_QUOTE_CHARACTER = '"';

    /** The quote constant to use when you wish to suppress all quoting. */
    public static final char NO_QUOTE_CHARACTER = '\u0000';

    /** The escape constant to use when you wish to suppress all escaping. */
    public static final char NO_ESCAPE_CHARACTER = '\u0000';

    /** Default line terminator uses platform encoding. */
    public static final String DEFAULT_LINE_END = "\n";

    /** Default column name. */
    public static final String DEFAULT_COLUMN_NAME = "Contact Name,Phone Number,";

    /**
     * Constructs CSVWriter using a comma for the separator.
     *
     * @param writer
     *            the writer to an underlying CSV source.
     */
    public CSVWriter(Writer writer) {
        this(writer, DEFAULT_SEPARATOR, DEFAULT_QUOTE_CHARACTER,
            DEFAULT_ESCAPE_CHARACTER, DEFAULT_LINE_END);
    }

    /**
     * Constructs CSVWriter with supplied separator, quote char, escape char and line ending.
     *
     * @param writer
     *            the writer to an underlying CSV source.
     * @param separator
     *            the delimiter to use for separating entries
     * @param quotechar
     *            the character to use for quoted elements
     * @param escapechar
     *            the character to use for escaping quotechars or escapechars
     * @param lineEnd
     *                    the line feed terminator to use
     */
    public CSVWriter(Writer writer, char separator, char quotechar, char escapechar, String lineEnd) {
        this.pw = new PrintWriter(writer);
        this.separator = separator;
        this.quotechar = quotechar;
        this.escapechar = escapechar;
        this.lineEnd = lineEnd;
    }

    /**
     * Writes the next line to the file.
     *
     * @param nextLine
     *            a string array with each comma-separated element as a separate
     *            entry.
     */
    public void writeNext(String[] nextLine) {

        if (nextLine == null)
                return;

        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < nextLine.length; i++) {

            if (i != 0) {
                sb.append(separator);
            }

            String nextElement = nextLine[i];
            if (nextElement == null)
                continue;
            if (quotechar !=  NO_QUOTE_CHARACTER)
                sb.append(quotechar);
            for (int j = 0; j < nextElement.length(); j++) {
                char nextChar = nextElement.charAt(j);
                if (escapechar != NO_ESCAPE_CHARACTER && nextChar == quotechar) {
                        sb.append(escapechar).append(nextChar);
                } else if (escapechar != NO_ESCAPE_CHARACTER && nextChar == escapechar) {
                        sb.append(escapechar).append(nextChar);
                } else {
                    sb.append(nextChar);
                }
            }
            if (quotechar != NO_QUOTE_CHARACTER)
                sb.append(quotechar);
        }

        sb.append(lineEnd);
        pw.write(sb.toString());

    }

    public void writeColumnNames() {
        writeNext(DEFAULT_COLUMN_NAME.split(","));
    }

    /**
     * Flush underlying stream to writer.
     *
     * @throws IOException if bad things happen
     */
    public void flush() throws IOException {
        pw.flush();
    }

    /**
     * Close the underlying stream writer flushing any buffered content.
     *
     * @throws IOException if bad things happen
     *
     */
    public void close() throws IOException {
        pw.flush();
        pw.close();
    }

}





07-29 15:35:51.742: ERROR/AndroidRuntime(8062): Caused by: java.lang.NullPointerException
07-29 15:35:51.742: ERROR/AndroidRuntime(8062):     at contactlist.pkg.CsvSender.createCSV(CsvSender.java:47)
07-29 15:35:51.742: ERROR/AndroidRuntime(8062):     at contactlist.pkg.CsvSender.onCreate(CsvSender.java:30)
07-29 15:35:51.742: ERROR/AndroidRuntime(8062):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-29 15:35:51.742: ERROR/AndroidRuntime(8062):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)