Audio Recording in android

1)AudioRecordingActivity.java
====================
package com.mrs.audiorecording;

import java.io.File;
import java.io.IOException;

import com.dipak.audiorecording.R;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class AudioRecordingActivity extends Activity {
    private static final String AUDIO_RECORDER_FILE_EXT_3GP = ".3gp";
    private static final String AUDIO_RECORDER_FILE_EXT_MP4 = ".mp4";
    private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";

    private MediaRecorder recorder = null;
    private int currentFormat = 0;
    private int output_formats[] = { MediaRecorder.OutputFormat.MPEG_4,
            MediaRecorder.OutputFormat.THREE_GPP };
    private String file_exts[] = { AUDIO_RECORDER_FILE_EXT_MP4,
            AUDIO_RECORDER_FILE_EXT_3GP };

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

        setButtonHandlers();
        enableButtons(false);
        setFormatButtonCaption();
    }

    private void setButtonHandlers() {
        ((Button) findViewById(R.id.btnStart)).setOnClickListener(btnClick);
        ((Button) findViewById(R.id.btnStop)).setOnClickListener(btnClick);
        ((Button) findViewById(R.id.btnFormat)).setOnClickListener(btnClick);
    }

    private void enableButton(int id, boolean isEnable) {
        ((Button) findViewById(id)).setEnabled(isEnable);
    }

    private void enableButtons(boolean isRecording) {
        enableButton(R.id.btnStart, !isRecording);
        enableButton(R.id.btnFormat, !isRecording);
        enableButton(R.id.btnStop, isRecording);
    }

    private void setFormatButtonCaption() {
        ((Button) findViewById(R.id.btnFormat))
                .setText(getString(R.string.audio_format) + " ("
                        + file_exts[currentFormat] + ")");
    }

    private String getFilename() {
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath, AUDIO_RECORDER_FOLDER);

        if (!file.exists()) {
            file.mkdirs();
        }

        return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + file_exts[currentFormat]);
    }

    private void startRecording() {
        recorder = new MediaRecorder();

        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(output_formats[currentFormat]);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(getFilename());

        recorder.setOnErrorListener(errorListener);
        recorder.setOnInfoListener(infoListener);

        try{
            recorder.prepare();
            recorder.start();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void stopRecording() {
        if (null != recorder) {
            recorder.stop();
            recorder.reset();
            recorder.release();
            recorder = null;
        }
    }

    private void displayFormatDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        String formats[] = { "MPEG 4", "3GPP" };

        builder.setTitle(getString(R.string.choose_format_title))
                .setSingleChoiceItems(formats, currentFormat,
                        new DialogInterface.OnClickListener() {

                            @Override
                            public void onClick(DialogInterface dialog,
                                    int which) {
                                currentFormat = which;
                                setFormatButtonCaption();

                                dialog.dismiss();
                            }
                        }).show();
    }

    private MediaRecorder.OnErrorListener errorListener = new MediaRecorder.OnErrorListener() {
        @Override
        public void onError(MediaRecorder mr, int what, int extra) {
            Toast.makeText(AudioRecordingActivity.this,
                    "Error: " + what + ", " + extra, Toast.LENGTH_SHORT).show();
        }
    };

    private MediaRecorder.OnInfoListener infoListener = new MediaRecorder.OnInfoListener() {
        @Override
        public void onInfo(MediaRecorder mr, int what, int extra) {
            Toast.makeText(AudioRecordingActivity.this,
                    "Warning: " + what + ", " + extra, Toast.LENGTH_SHORT)
                    .show();
        }
    };

    private View.OnClickListener btnClick = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.btnStart: {
                Toast.makeText(AudioRecordingActivity.this, "Start Recording",
                        Toast.LENGTH_SHORT).show();

                enableButtons(true);
                startRecording();

                break;
            }
            case R.id.btnStop: {
                Toast.makeText(AudioRecordingActivity.this, "Stop Recording",
                        Toast.LENGTH_SHORT).show();
                enableButtons(false);
                stopRecording();

                break;
            }
            case R.id.btnFormat: {
                displayFormatDialog();

                break;
            }
            }
        }
    };
}
2)main.xml
========
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="20dip">
   
    <ImageView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        android:scaleType="fitCenter"/>
   
        <TextView 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/app_info"
        android:layout_weight="1.0"
        android:textSize="20dip"/>
       
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
       
        <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/btnStart"
                android:text="@string/start_recording"
                android:layout_weight="1.0"/>
               
                <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/btnStop"
                android:text="@string/stop_recording"
                android:layout_weight="1.0"/>
               
        <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/btnFormat"
                android:text="Format (mp4)"
                android:layout_weight="1.0"/>
       
    </LinearLayout>
</LinearLayout>
3)manifest.xml
=========
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.dipak.audiorecording"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="10" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:smallScreens="true"
        android:xlargeScreens="true" />
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name="com.mrs.audiorecording.AudioRecordingActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>
4)strings.xml
=========
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="hello">Hello World, AudioRecordingActivity!</string>
    <string name="app_info">This is a sample application to record audio.\n\nTo start recording press \"Record\" button, to stop recording press \"Stop\" button.</string>
    <string name="app_name">Audio Recorder</string>
    <string name="choose_format_title">Choose Audio Format</string>
    <string name="start_recording">Record</string>
    <string name="stop_recording">Stop</string>
    <string name="audio_format">Format</string>

</resources>