DateFormattingTests.java

/*
 * Copyright 2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.example.myapi;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.TimeZone;

import org.junit.Test;

public class DateFormattingTests {

	private static final int ITERATIONS = 5000000;

	@Test
	public void testname() {

		LocalDateTime now = LocalDateTime.now();

		DateTimeFormatter formatter = DateTimeFormatter.ISO_DATE_TIME;

		long startTime = System.currentTimeMillis();

		for (int i = 0; i < ITERATIONS; i++) {
			formatter.format(now);
		}

		long duration = (System.currentTimeMillis() - startTime);

		System.out.println("Converting LocalDateTime took " + duration + "ms");
	}

	@Test
	public void testname2() {

		TimeZone tz = TimeZone.getTimeZone("UTC");
		DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'"); // Quoted "Z" to indicate UTC, no timezone offset
		df.setTimeZone(tz);

		Date now = new Date();

		long startTime = System.currentTimeMillis();

		for (int i = 0; i < ITERATIONS; i++) {
			df.format(now);
		}

		long duration = (System.currentTimeMillis() - startTime);

		System.out.println("Converting Date took " + duration + "ms");
	}
}

output.txt

Converting Date took 3944ms
Converting LocalDateTime took 18020ms