AS時間関連①解説～今の時間を表示する～

package com.example.localdatetimeapp;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
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.textView);

        LocalDateTime ldt = LocalDateTime.now();
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd hh:mm:ss");
        textView.setText(ldt.format(dtf));
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:gravity="center_horizontal">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:layout_marginTop="160sp"/>

</LinearLayout>