Androidでのタイマーカウントダウン

Question

Androidアプリケーション開発に新しい、私は何か間違いがあったら申し訳ありません。自分のコードごとにhomeActivityにアクセスするたびに、タイマーのカウントダウンを開始するにはどうすればいいですか。ありがとうございました。

public class homeActivity extends AppCompatActivity { 
    private TextView userEmail; // Declaring email textview 
    private TextView timerDisplay; // Declaring Timer Display textview 

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

     userEmail = (TextView) findViewById(R.id.userEmailID); 
     timerDisplay = (TextView) findViewById(R.id.timer); 
     // Retriving the the email id of the user which was passed from the sigin Activity 
     userEmail.setText(getIntent().getExtras().getString("Email")); 

     //use of a timer to display the notification 40 seconds as default for testing purposes 
     new CountDownTimer(40000, 1000) { 

      public void onTick(long millisUntilFinished) { 
       // Displaying the following timer on the textview 
       timerDisplay.setText("seconds remaining: " + millisUntilFinished/1000); 
      } 
      //once the timer stops the following notification message is being Displayed 
      public void onFinish() { 
       final String title1="Break!"; 
       String subject1="It is time to take a break"; 
       String body1="20 minutes have passed"; 

       // Break taken is displayed on the textview 
       timerDisplay.setText("Break Taken"); 
       // notification is diplayed 
       NotificationManager notif=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE); 
       Notification notify=new Notification.Builder 
         (getApplicationContext()).setContentTitle(title1).setContentText(body1). 
         setContentTitle(subject1).setSmallIcon(R.mipmap.iclauncher).build(); 

       notify.flags |= Notification.FLAG_AUTO_CANCEL; 
       notif.notify(0, notify); 
      } 
     }.start(); 
    } 

    // Directed to rate us Activity 
    public void rateusOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,rateUsActivity.class); 
     startActivity(intent); 
    } 

    // Directed to daily offers Activity 
    public void dailyOffersOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,dailyOffersActivity.class); 
     startActivity(intent); 
    } 

    // directed to statistics Activity 
    public void statisticsOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,statisticsActivity.class); 
     startActivity(intent); 
    } 

    // directed to privacy policy Activity 
    public void privacyPolicyOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,privacyPolicyActivity.class); 
     startActivity(intent); 
    } 

    // Directed back to sign in Activity 
    public void logoutOperation (View v){ 
     AlertDialog.Builder altDial = new AlertDialog.Builder (homeActivity.this); 
     altDial.setMessage("Are You Sure ? ").setCancelable(true) 
       .setPositiveButton("Yes", new DialogInterface.OnClickListener(){ 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         Intent intent = new Intent(homeActivity.this,MainActivity.class); 
         startActivity(intent); 
         finish(); 
        } 
       }) 
       .setNegativeButton("No", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         dialog.cancel(); 
        } 
       }); 
     AlertDialog alert = altDial.create(); 
     alert.setTitle("You want to Logout "); 
     alert.show(); 
    } 
} 

Answer 1

public class homeActivity extends AppCompatActivity 
{ 
    private TextView userEmail; // Declaring email textview 
    private TextView timerDisplay; // Declaring Timer Display textview 

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

     userEmail = (TextView) findViewById(R.id.userEmailID); 
     timerDisplay = (TextView) findViewById(R.id.timer); 
     // Retriving the the email id of the user which was passed from the sigin Activity 
     userEmail.setText(getIntent().getExtras().getString("Email")); 

     final CounterClass timer2 = new CounterClass(4000, 1000); 
       timer2.start(); 
    } 

    // Directed to rate us Activity 
    public void rateusOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,rateUsActivity.class); 
     startActivity(intent); 
    } 

    // Directed to daily offers Activity 
    public void dailyOffersOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,dailyOffersActivity.class); 
     startActivity(intent); 
    } 

    // directed to statistics Activity 
    public void statisticsOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,statisticsActivity.class); 
     startActivity(intent); 
    } 

    // directed to privacy policy Activity 
    public void privacyPolicyOperation (View v){ 
     Intent intent = new Intent(homeActivity.this,privacyPolicyActivity.class); 
     startActivity(intent); 
    } 

    // Directed back to sign in Activity 
    public void logoutOperation (View v){ 
     AlertDialog.Builder altDial = new AlertDialog.Builder (homeActivity.this); 
     altDial.setMessage("Are You Sure ? ").setCancelable(true) 
       .setPositiveButton("Yes", new DialogInterface.OnClickListener(){ 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         Intent intent = new Intent(homeActivity.this,MainActivity.class); 
         startActivity(intent); 
         finish(); 
        } 
       }) 
       .setNegativeButton("No", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         dialog.cancel(); 
        } 
       }); 
     AlertDialog alert = altDial.create(); 
     alert.setTitle("You want to Logout "); 
     alert.show(); 
    } 
public class CounterClass extends CountDownTimer 
    { 
     TextView conter; 
     public CounterClass(long millisInFuture, long countDownInterval) 
     { 
      super(millisInFuture, countDownInterval); 

     } 
     @Override 
     public void onFinish() 
     { 
      final String title1="Break!"; 
       String subject1="It is time to take a break"; 
       String body1="20 minutes have passed"; 

       // Break taken is displayed on the textview 
       timerDisplay.setText("Break Taken"); 
       // notification is diplayed 
       NotificationManager notif=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE); 
       Notification notify=new Notification.Builder 
         (getApplicationContext()).setContentTitle(title1).setContentText(body1). 
         setContentTitle(subject1).setSmallIcon(R.mipmap.iclauncher).build(); 

       notify.flags |= Notification.FLAG_AUTO_CANCEL; 
       notif.notify(0, notify); 
     } 
     @SuppressLint("NewApi") 
     @TargetApi(Build.VERSION_CODES.GINGERBREAD) 
     @Override 
     public void onTick(long millisUntilFinished) 
     { 
      long millis = millisUntilFinished; 
      String hms = String.format("%02d:%02d", 
        TimeUnit.MILLISECONDS.toMinutes(millis) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(millis)), 
        TimeUnit.MILLISECONDS.toSeconds(millis) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))); 

      timerDisplay.setText(hms); 
     } 
    } 

}