Here is source code of the Program to Demonstrate Button with Rounded Corners in Android. The program is successfully compiled and run on a Windows system using Eclipse Ide. The program output is also shown below.
In order to Demonstrate Button with Rounded Corners i have defined a style for my text view in /res/drawable folder with name mystyle and applied this as a background to my Button , the following code demonstrates this.

Main Activity

package com.example.text_view_rounded;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.widget.VideoView;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button but = (Button) findViewById(R.id.button1);
but.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), "On Click",
Toast.LENGTH_LONG).show();
}
});
}

@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;
}

}

mystyle

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item android:state_focused="true" android:state_pressed="true"><shape>
<stroke android:width="2.3dp" android:color="#a7bf42" />

<corners android:radius="10dp" />
</shape></item>
<item android:state_focused="false" android:state_pressed="true"><shape>
<stroke android:width="2.3dp" android:color="#a7bf42" />

<corners android:radius="10dp" />
</shape></item>
<item android:state_focused="true" android:state_pressed="false"><shape>
<stroke android:width="0.7dp" android:color="#000000" />

<corners android:radius="15dp" />
</shape></item>
<item android:state_focused="false" android:state_pressed="false"><shape>
<gradient android:angle="270" android:centerColor="#F6EBC9" android:endColor="#a7bf42" android:startColor="#a7bf42" />

<stroke android:width="0.7dp" android:color="#000000" />

<corners android:radius="15dp" />
</shape></item>
<item android:state_enabled="true"><shape>
<padding android:bottom="4dp" android:left="4dp" android:right="4dp" android:top="4dp" />
</shape></item>

</selector>

Activity_Main

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:text="Round Cornered Button"
android:background="@drawable/mystyle"/>

</RelativeLayout>