BAEL-1683-Guide to Java Clock class

core-java/src/main/java/com/baeldung/clock/ClockExample.java

@@ -0,0 +1,83 @@
+package com.baeldung.clock;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneId;
+
+public class ClockExample {
+
+	public static void main(String[] args) {
+
+		// gets systemUTC
+		Clock clockUTC = Clock.systemUTC();
+		System.out.println("UTC time :: " + clockUTC.instant());
+
+		// using system()
+		Clock clockSystem = Clock.system(ZoneId.of("Asia/Kolkata"));
+		System.out.println(clockSystem.instant());
+
+		// gets systemDefaultZone
+		Clock clockSystemDefault = Clock.systemDefaultZone();
+		System.out.println(clockSystemDefault);
+		clockSystemDefault = Clock.system(ZoneId.systemDefault());
+		System.out.println(clockSystemDefault);
+
+		// gets instant from system default zone
+		Clock clockInstant = Clock.systemDefaultZone();
+		Instant instant = clockInstant.instant();
+		System.out.println(instant);
+
+		// gets millis
+		Clock millis = Clock.systemDefaultZone();
+		System.out.println(millis.millis());
+		System.out.println(System.currentTimeMillis());
+
+		// using offset
+
+		Clock baseClock = Clock.systemDefaultZone();
+		// result clock will be later than baseClock
+		Clock clock5 = Clock.offset(baseClock, Duration.ofHours(72));
+		System.out.println(clock5.instant());
+
+		// result clock will be same as baseClock
+		clock5 = Clock.offset(baseClock, Duration.ZERO);
+		System.out.println(clock5.instant());
+
+		// result clock will be earlier than baseClock
+		clock5 = Clock.offset(baseClock, Duration.ofHours(-72));
+		System.out.println(clock5.instant());
+
+		// using tick
+		Clock clockDefaultZone = Clock.systemDefaultZone();
+		Clock clocktick = Clock.tick(clockDefaultZone, Duration.ofSeconds(30));
+		System.out.println("Clock Default Zone : " + clockDefaultZone.instant());
+		System.out.println("Clock tick : " + clocktick.instant());
+
+		// using tickMinutes
+		Clock tickMinutes = Clock.tickMinutes(ZoneId.of("Asia/Kolkata"));
+		System.out.println(tickMinutes.instant());
+		tickMinutes = Clock.tick(Clock.system(ZoneId.of("Asia/Kolkata")), Duration.ofMinutes(1));
+		System.out.println(tickMinutes.instant());
+
+		// using tickSeconds
+		ZoneId zoneId = ZoneId.of("Asia/Calcutta");
+		Clock tickSeconds = Clock.tickSeconds(zoneId);
+		System.out.println(tickSeconds.instant());
+		tickSeconds = Clock.tick(Clock.system(ZoneId.of("Asia/Kolkata")), Duration.ofSeconds(1));
+		System.out.println(tickSeconds.instant());
+
+		// using withZone
+		ZoneId zone1 = ZoneId.of("Asia/Singapore");
+		Clock clock11 = Clock.system(zone1);
+		System.out.println(clock11.instant());
+
+		ZoneId zone2 = ZoneId.of("Asia/Kolkata");
+		Clock clock21 = clock11.withZone(zone2);
+		System.out.println(clock21.instant());
+
+		ZoneId zone = clockDefaultZone.getZone();
+		System.out.println(zone.getId());
+
+	}
+}