<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity">
 <TextView
   android:id="@+id/date"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Local Date"
   app:layout_constraintBottom_toBottomOf="parent"
   app:layout_constraintLeft_toLeftOf="parent"
   app:layout_constraintRight_toRightOf="parent"
   app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

package com.example.myapplication;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class MainActivity extends AppCompatActivity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);
   TextView textView = findViewById(R.id.date);
   if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
    LocalDateTime time = LocalDateTime.now();
    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss");
    dateTimeFormatter.format(time);
    textView.setText(String.valueOf("Date & Time" + time));
   }
 }
}