This Android Java Program lets you create a Count Down Timer Application.
Here is source code of the Program to create a Count Down Timer Application. The program is successfully compiled and run on a Windows system using Eclipse Ide. The program output is also shown below.

Main Activity


package com.example.contdowntimer;

import android.os.Bundle;
import android.os.CountDownTimer;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {

private santimer timer;
private Boolean timer_flag=false;
private final long startTime = 50000;
private final long interval = 1000;
private Button start;
private TextView text,time_eplapsed;
private long timeElapsed;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
start = (Button) findViewById(R.id.startbutton);
start.setOnClickListener(this);
text = (TextView) findViewById(R.id.timer);
time_eplapsed = (TextView) findViewById(R.id.timeElapsed);
timer = new santimer(startTime, interval);
text.setText(text.getText() + String.valueOf(startTime));
}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (!timer_flag) {
timer.start();
timer_flag = true;
start.setText("Start");
} else {
timer.cancel();
timer_flag = false;
start.setText("Reset");
}
}

private class santimer extends CountDownTimer {

public santimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
// TODO Auto-generated constructor stub

}

@Override
public void onFinish() {
// TODO Auto-generated method stub
text.setText("Time's up!");
time_eplapsed.setText("Time Elapsed: " + String.valueOf(startTime));
}

@Override
public void onTick(long millisUntilFinished) {
// TODO Auto-generated method stub
text.setText("Time remain:" + millisUntilFinished);
timeElapsed = startTime - millisUntilFinished;
time_eplapsed.setText("Time Elapsed: "
+ String.valueOf(timeElapsed));
}

}
}


MainXml

<LinearLayout 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:orientation="vertical" >

<Button
android:id="@+id/startbutton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Start"
android:textAlignment="center"
>
</Button>

<TableLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="10dp" >

<TableRow>

<TextView
android:id="@+id/timer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingRight="10dp"
android:text="Time: "
android:textSize="20dp" />
</TableRow>
</TableLayout>

<TextView
android:id="@+id/timeElapsed"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="Time elapsed: "
android:textSize="20dp" />

</LinearLayout>