public class CDlowder extends Thread {
    @Override
    public void run() {
        for(int i = 0; i < 100; i++)
        {
            try {
                this.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            Log.d("ALERT!!", "now I is: " + i);
        }
    }
}

public class MainActivity extends AppCompatActivity {
    CDlowder cDlowder;
    TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button button = (Button) findViewById(R.id.button);
        Button buttonCancel = (Button)findViewById(R.id.button2);
        tv = (TextView)findViewById(R.id.textView);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                cDlowder = new CDlowder();
                cDlowder.run();
            }

        });

        buttonCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (cDlowder.isAlive() == true) {
                    cDlowder.interrupt();
                }
                tv.setText("I can do things");
            }
        });
    }
}