How to display a timer in a TextView in Android?

int time=30;
TextView textTimer = (TextView)findViewById(R.id.timer);

new CountDownTimer(30000, 1000) {

    public void onTick(long millisUntilFinished) {  
        textTimer.setText("0:"+checkDigit(time));
        time--;         
    }

    public void onFinish() {
        textTimer.setText("try again");
    }

}.start();



public String checkDigit(int number) {
    return number <= 9 ? "0" + number : String.valueOf(number);
}

Try code:

import java.util.Timer;
import java.util.TimerTask;

import android.os.Bundle;
import android.widget.TextView;
import android.app.Activity;

public class MainActivity extends Activity {

    public int seconds = 60;
    public int minutes = 10;

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

        //Declare the timer
        Timer t = new Timer();
        //Set the schedule function and rate
        t.scheduleAtFixedRate(new TimerTask() {

            @Override
            public void run() {
                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        TextView tv = (TextView) findViewById(R.id.main_timer_text);
                        tv.setText(String.valueOf(minutes)+":"+String.valueOf(seconds));
                        seconds -= 1;

                        if(seconds == 0)
                        {
                            tv.setText(String.valueOf(minutes)+":"+String.valueOf(seconds));

                            seconds=60;
                            minutes=minutes-1;

                        }



                    }

                });
            }

        }, 0, 1000);
    }

}

XML File

<?xml version="1.0" encoding="utf-8"?>
<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"
    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">

    <TextView
        android:id="@+id/mtextTimer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/buttonSend"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Start" />
</LinearLayout>

Activity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private TextView textTimer;

    private Button StartTimer;


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

        //Initializing the views
        textTimer = (TextView) findViewById(R.id.mtextTimer);

        StartTimer = (Button) findViewById(R.id.buttonSend);

        StartTimer.setOnClickListener(this);


    }


    @Override
    public void onClick(View v) {


        long maxTimeInMilliseconds = 30000;// in your case

        startTimer(maxTimeInMilliseconds, 1000);

    }

    public void startTimer(final long finish, long tick) {
        CountDownTimer t;
        t = new CountDownTimer(finish, tick) {

            public void onTick(long millisUntilFinished) {
                long remainedSecs = millisUntilFinished / 1000;
                textTimer.setText("" + (remainedSecs / 60) + ":" + (remainedSecs % 60));// manage it accordign to you
            }

            public void onFinish() {
                textTimer.setText("00:00:00");
                Toast.makeText(MainActivity.this, "Finish", Toast.LENGTH_SHORT).show();

                cancel();
            }
        }.start();
    }
}