ojluni/src/test/java/nio/file/attribute/FileTimeTest.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /* @test
  * @bug 6844313 8011647
  * @summary Unit test for java.nio.file.FileTime
  */
 // Android-changed: Adapted from
 // jdk/test/java/nio/file/attribute/FileTime/Basic.java
 // Android-changed: Added package & Test import
 package test.java.nio.file.attribute;
 import org.testng.annotations.Test;

 import java.nio.file.attribute.FileTime;
 import java.time.Instant;
 import java.util.concurrent.TimeUnit;
 import static java.util.concurrent.TimeUnit.*;
 import java.util.Random;
 import java.util.EnumSet;

 // Android-changed: Renamed from "Basic"
 public class FileTimeTest {

     static final Random rand = new Random();

     // Android-changed: Removed args & added @Test
     @Test
     public static void main() {
         long now = System.currentTimeMillis();
         long tomorrowInDays = TimeUnit.DAYS.convert(now, MILLISECONDS) + 1;
         long yesterdayInDays = TimeUnit.DAYS.convert(now, MILLISECONDS) - 1;

         Instant nowInstant = Instant.ofEpochMilli(now);

         // equals
         eq(now, MILLISECONDS, now, MILLISECONDS);
         eq(now, MILLISECONDS, now*1000L, MICROSECONDS);
         neq(now, MILLISECONDS, 0, MILLISECONDS);
         neq(now, MILLISECONDS, 0, MICROSECONDS);

         eq(nowInstant, now, MILLISECONDS);
         eq(nowInstant, now*1000L, MICROSECONDS);
         neq(nowInstant, 0, MILLISECONDS);
         neq(nowInstant, 0, MICROSECONDS);

         // compareTo
         cmp(now, MILLISECONDS, now, MILLISECONDS, 0);
         cmp(now, MILLISECONDS, now*1000L, MICROSECONDS, 0);
         cmp(now, MILLISECONDS, now-1234, MILLISECONDS, 1);
         cmp(now, MILLISECONDS, now+1234, MILLISECONDS, -1);

         cmp(tomorrowInDays, DAYS, now, MILLISECONDS, 1);
         cmp(now, MILLISECONDS, tomorrowInDays, DAYS, -1);
         cmp(yesterdayInDays, DAYS, now, MILLISECONDS, -1);
         cmp(now, MILLISECONDS, yesterdayInDays, DAYS, 1);
         cmp(yesterdayInDays, DAYS, now, MILLISECONDS, -1);

         cmp(Long.MAX_VALUE, DAYS, Long.MAX_VALUE, NANOSECONDS, 1);
         cmp(Long.MAX_VALUE, DAYS, Long.MIN_VALUE, NANOSECONDS, 1);
         cmp(Long.MIN_VALUE, DAYS, Long.MIN_VALUE, NANOSECONDS, -1);
         cmp(Long.MIN_VALUE, DAYS, Long.MAX_VALUE, NANOSECONDS, -1);

         cmp(Instant.MIN, Long.MIN_VALUE, DAYS, 1);
         cmp(Instant.MIN, Long.MIN_VALUE, HOURS, 1);
         cmp(Instant.MIN, Long.MIN_VALUE, MINUTES, 1);
         cmp(Instant.MIN, Long.MIN_VALUE, SECONDS, 1);
         cmp(Instant.MIN, Instant.MIN.getEpochSecond() - 1, SECONDS, 1);
         cmp(Instant.MIN, Instant.MIN.getEpochSecond() - 100, SECONDS, 1);
         cmp(Instant.MIN, Instant.MIN.getEpochSecond(), SECONDS, 0);

         cmp(Instant.MAX, Long.MAX_VALUE, DAYS, -1);
         cmp(Instant.MAX, Long.MAX_VALUE, HOURS, -1);
         cmp(Instant.MAX, Long.MAX_VALUE, MINUTES, -1);
         cmp(Instant.MAX, Long.MAX_VALUE, SECONDS, -1);
         cmp(Instant.MAX, Instant.MAX.getEpochSecond() + 1, SECONDS, -1);
         cmp(Instant.MAX, Instant.MAX.getEpochSecond() + 100, SECONDS, -1);
         cmp(Instant.MAX, Instant.MAX.getEpochSecond(), SECONDS, 0);

         cmp(nowInstant, now, MILLISECONDS, 0);
         cmp(nowInstant, now*1000L, MICROSECONDS, 0);
         cmp(nowInstant, now-1234, MILLISECONDS, 1);
         cmp(nowInstant, now+1234, MILLISECONDS, -1);
         cmp(nowInstant, tomorrowInDays, DAYS, -1);
         cmp(nowInstant, yesterdayInDays, DAYS, 1);

         // to(TimeUnit)
         to(MILLISECONDS.convert(1, DAYS) - 1, MILLISECONDS);
         to(MILLISECONDS.convert(1, DAYS) + 0, MILLISECONDS);
         to(MILLISECONDS.convert(1, DAYS) + 1, MILLISECONDS);
         to(1, MILLISECONDS);
         to(0, MILLISECONDS);
         to(1, MILLISECONDS);
         to(MILLISECONDS.convert(-1, DAYS) - 1, MILLISECONDS);
         to(MILLISECONDS.convert(-1, DAYS) + 0, MILLISECONDS);
         to(MILLISECONDS.convert(-1, DAYS) + 1, MILLISECONDS);
         for (TimeUnit unit: TimeUnit.values()) {
             for (int i=0; i<100; i++) { to(rand.nextLong(), unit); }
             to(Long.MIN_VALUE, unit);
             to(Long.MAX_VALUE, unit);
         }

         // toInstant()
         int N = 1000;
         for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
             for (int i = 0; i < N; i++) {
                 long value = rand.nextLong();
                 FileTime ft = FileTime.from(value, unit);
                 Instant instant = ft.toInstant();
                 if (instant != Instant.MIN && instant != Instant.MAX) {
                     eqTime(value, unit, instant);
                 }
             }
         }
         for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
             long value = Long.MIN_VALUE;
             FileTime ft = FileTime.from(value, unit);
             Instant instant = ft.toInstant();
             if (unit.compareTo(TimeUnit.SECONDS) < 0) {
                 eqTime(value, unit, instant);
             } else if (!instant.equals(Instant.MIN)) {
                 throw new RuntimeException("should overflow to MIN");
             }
             value = Long.MAX_VALUE;
             ft = FileTime.from(value, unit);
             instant = ft.toInstant();
             if (unit.compareTo(TimeUnit.SECONDS) < 0) {
                 eqTime(value, unit, instant);
             } else if (!instant.equals(Instant.MAX)) {
                 throw new RuntimeException("should overflow to MAX");
             }
         }

         // from(Instant)
         final long MAX_SECOND = 31556889864403199L;
         for (int i = 0; i < N; i++) {
             long v = rand.nextLong();
             long secs = v % MAX_SECOND;
             Instant instant = Instant.ofEpochSecond(secs, rand.nextInt(1000_000_000));
             FileTime ft = FileTime.from(instant);
             if (!ft.toInstant().equals(instant) || ft.to(SECONDS)  != secs) {
                 throw new RuntimeException("from(Instant) failed");
             }
             long millis = v;
             instant = Instant.ofEpochMilli(millis);
             ft = FileTime.from(instant);
             if (!ft.toInstant().equals(instant) ||
                 ft.toMillis()  != instant.toEpochMilli()) {
                 throw new RuntimeException("from(Instant) failed");
             }
             long nanos = v;
             ft = FileTime.from(nanos, NANOSECONDS);
             secs = nanos / 1000_000_000;
             nanos = nanos % 1000_000_000;
             instant = Instant.ofEpochSecond(secs, nanos);
             if (!ft.equals(FileTime.from(instant))) {
                 throw new RuntimeException("from(Instant) failed");
             }
         }

         // toString
         ts(1L, DAYS, "1970-01-02T00:00:00Z");
         ts(1L, HOURS, "1970-01-01T01:00:00Z");
         ts(1L, MINUTES, "1970-01-01T00:01:00Z");
         ts(1L, SECONDS, "1970-01-01T00:00:01Z");
         ts(1L, MILLISECONDS, "1970-01-01T00:00:00.001Z");
         ts(1L, MICROSECONDS, "1970-01-01T00:00:00.000001Z");
         ts(1L, NANOSECONDS, "1970-01-01T00:00:00.000000001Z");
         ts(999999999L, NANOSECONDS, "1970-01-01T00:00:00.999999999Z");
         ts(9999999999L, NANOSECONDS, "1970-01-01T00:00:09.999999999Z");

         ts(-1L, DAYS, "1969-12-31T00:00:00Z");
         ts(-1L, HOURS, "1969-12-31T23:00:00Z");
         ts(-1L, MINUTES, "1969-12-31T23:59:00Z");
         ts(-1L, SECONDS, "1969-12-31T23:59:59Z");
         ts(-1L, MILLISECONDS, "1969-12-31T23:59:59.999Z");
         ts(-1L, MICROSECONDS, "1969-12-31T23:59:59.999999Z");
         ts(-1L, NANOSECONDS, "1969-12-31T23:59:59.999999999Z");
         ts(-999999999L, NANOSECONDS, "1969-12-31T23:59:59.000000001Z");
         ts(-9999999999L, NANOSECONDS, "1969-12-31T23:59:50.000000001Z");

         ts(-62135596799999L, MILLISECONDS, "0001-01-01T00:00:00.001Z");
         ts(-62135596800000L, MILLISECONDS, "0001-01-01T00:00:00Z");
         ts(-62135596800001L, MILLISECONDS, "-0001-12-31T23:59:59.999Z");

         ts(253402300799999L, MILLISECONDS, "9999-12-31T23:59:59.999Z");
         ts(-377642044800001L, MILLISECONDS, "-9999-12-31T23:59:59.999Z");

         // NTFS epoch in usec.
         ts(-11644473600000000L, MICROSECONDS, "1601-01-01T00:00:00Z");

         ts(Instant.MIN, "-1000000001-01-01T00:00:00Z");
         ts(Instant.MAX, "1000000000-12-31T23:59:59.999999999Z");

         try {
             FileTime.from(0L, null);
             throw new RuntimeException("NullPointerException expected");
         } catch (NullPointerException npe) { }
         try {
             FileTime.from(null);
             throw new RuntimeException("NullPointerException expected");
         } catch (NullPointerException npe) { }

         FileTime time = FileTime.fromMillis(now);
         if (time.equals(null))
             throw new RuntimeException("should not be equal to null");
         try {
             time.compareTo(null);
             throw new RuntimeException("NullPointerException expected");
         } catch (NullPointerException npe) { }

         // Instant + toMilli() overflow
         overflow(Long.MAX_VALUE,
                  FileTime.from(Instant.MAX).toMillis());
         overflow(Long.MAX_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000 + 1))
                          .toMillis());
         overflow(Long.MIN_VALUE,
                  FileTime.from(Instant.MIN).toMillis());
         overflow(Long.MIN_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000 - 1))
                          .toMillis());

         // Instant + to(TimeUnit) overflow
         overflow(Long.MAX_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000 + 1))
                          .to(MILLISECONDS));
         overflow(Long.MAX_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000,
                                                      MILLISECONDS.toNanos(1000)))
                     .to(MILLISECONDS));
         overflow(Long.MIN_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000 - 1))
                          .to(MILLISECONDS));
         overflow(Long.MIN_VALUE,
                  FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000,
                                                      -MILLISECONDS.toNanos(1)))
             .to(MILLISECONDS));
     }

     static void overflow(long minmax, long v) {
         if (v != minmax)
             throw new RuntimeException("saturates to Long.MIN/MAX_VALUE expected");
     }

     static void cmp(long v1, TimeUnit u1, long v2, TimeUnit u2, int expected) {
         int result = FileTime.from(v1, u1).compareTo(FileTime.from(v2, u2));
         if (result != expected)
             throw new RuntimeException("unexpected order");
     }

     static void cmp(Instant ins, long v2, TimeUnit u2, int expected) {
         int result = FileTime.from(ins).compareTo(FileTime.from(v2, u2));
         if (result != expected)
             throw new RuntimeException("unexpected order");
     }

     static void eq(long v1, TimeUnit u1, long v2, TimeUnit u2) {
         FileTime t1 = FileTime.from(v1, u1);
         FileTime t2 = FileTime.from(v2, u2);
         if (!t1.equals(t2))
             throw new RuntimeException("not equal");
         if (t1.hashCode() != t2.hashCode())
             throw new RuntimeException("hashCodes should be equal");
     }

     static void eq(Instant ins, long v2, TimeUnit u2) {
         FileTime t1 = FileTime.from(ins);
         FileTime t2 = FileTime.from(v2, u2);
         if (!t1.equals(t2))
             throw new RuntimeException("not equal");
         if (t1.hashCode() != t2.hashCode())
             throw new RuntimeException("hashCodes should be equal");
     }

     static void eqTime(long value, TimeUnit unit, Instant instant) {
         long secs = SECONDS.convert(value, unit);
         long nanos = NANOSECONDS.convert(value - unit.convert(secs, SECONDS), unit);
         if (nanos < 0) {    // normalize nanoOfSecond to positive
             secs -= 1;
             nanos += 1000_000_000;
         }
         if (secs != instant.getEpochSecond() || (int)nanos != instant.getNano()) {
             System.err.println(" ins=" + instant);
             throw new RuntimeException("ft and instant are not the same time point");
         }
     }

     static void neq(long v1, TimeUnit u1, long v2, TimeUnit u2) {
         FileTime t1 = FileTime.from(v1, u1);
         FileTime t2 = FileTime.from(v2, u2);
         if (t1.equals(t2))
             throw new RuntimeException("should not be equal");
     }

     static void neq(Instant ins, long v2, TimeUnit u2) {
         FileTime t1 = FileTime.from(ins);
         FileTime t2 = FileTime.from(v2, u2);
         if (t1.equals(t2))
             throw new RuntimeException("should not be equal");
     }

     static void to(long v, TimeUnit unit) {
         FileTime t = FileTime.from(v, unit);
         for (TimeUnit u: TimeUnit.values()) {
             long result = t.to(u);
             long expected = u.convert(v, unit);
             if (result != expected) {
                 throw new RuntimeException("unexpected result");
             }
         }
     }

     static void ts(long v, TimeUnit unit, String expected) {
         String result = FileTime.from(v, unit).toString();
         if (!result.equals(expected)) {
             System.err.format("FileTime.from(%d, %s).toString() failed\n", v, unit);
             System.err.format("Expected: %s\n", expected);
             System.err.format("     Got: %s\n", result);
             throw new RuntimeException();
         }
     }

     static void ts(Instant instant, String expected) {
         String result = FileTime.from(instant).toString();
         if (!result.equals(expected)) {
             System.err.format("FileTime.from(%s).toString() failed\n", instant);
             System.err.format("Expected: %s\n", expected);
             System.err.format("     Got: %s\n", result);
             throw new RuntimeException();
         }
     }
 }
	/*
	* Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/* @test
	* @bug 6844313 8011647
	* @summary Unit test for java.nio.file.FileTime
	*/
	// Android-changed: Adapted from
	// jdk/test/java/nio/file/attribute/FileTime/Basic.java
	// Android-changed: Added package & Test import
	package test.java.nio.file.attribute;
	import org.testng.annotations.Test;

	import java.nio.file.attribute.FileTime;
	import java.time.Instant;
	import java.util.concurrent.TimeUnit;
	import static java.util.concurrent.TimeUnit.*;
	import java.util.Random;
	import java.util.EnumSet;

	// Android-changed: Renamed from "Basic"
	public class FileTimeTest {

	static final Random rand = new Random();

	// Android-changed: Removed args & added @Test
	@Test
	public static void main() {
	long now = System.currentTimeMillis();
	long tomorrowInDays = TimeUnit.DAYS.convert(now, MILLISECONDS) + 1;
	long yesterdayInDays = TimeUnit.DAYS.convert(now, MILLISECONDS) - 1;

	Instant nowInstant = Instant.ofEpochMilli(now);

	// equals
	eq(now, MILLISECONDS, now, MILLISECONDS);
	eq(now, MILLISECONDS, now*1000L, MICROSECONDS);
	neq(now, MILLISECONDS, 0, MILLISECONDS);
	neq(now, MILLISECONDS, 0, MICROSECONDS);

	eq(nowInstant, now, MILLISECONDS);
	eq(nowInstant, now*1000L, MICROSECONDS);
	neq(nowInstant, 0, MILLISECONDS);
	neq(nowInstant, 0, MICROSECONDS);

	// compareTo
	cmp(now, MILLISECONDS, now, MILLISECONDS, 0);
	cmp(now, MILLISECONDS, now*1000L, MICROSECONDS, 0);
	cmp(now, MILLISECONDS, now-1234, MILLISECONDS, 1);
	cmp(now, MILLISECONDS, now+1234, MILLISECONDS, -1);

	cmp(tomorrowInDays, DAYS, now, MILLISECONDS, 1);
	cmp(now, MILLISECONDS, tomorrowInDays, DAYS, -1);
	cmp(yesterdayInDays, DAYS, now, MILLISECONDS, -1);
	cmp(now, MILLISECONDS, yesterdayInDays, DAYS, 1);
	cmp(yesterdayInDays, DAYS, now, MILLISECONDS, -1);

	cmp(Long.MAX_VALUE, DAYS, Long.MAX_VALUE, NANOSECONDS, 1);
	cmp(Long.MAX_VALUE, DAYS, Long.MIN_VALUE, NANOSECONDS, 1);
	cmp(Long.MIN_VALUE, DAYS, Long.MIN_VALUE, NANOSECONDS, -1);
	cmp(Long.MIN_VALUE, DAYS, Long.MAX_VALUE, NANOSECONDS, -1);

	cmp(Instant.MIN, Long.MIN_VALUE, DAYS, 1);
	cmp(Instant.MIN, Long.MIN_VALUE, HOURS, 1);
	cmp(Instant.MIN, Long.MIN_VALUE, MINUTES, 1);
	cmp(Instant.MIN, Long.MIN_VALUE, SECONDS, 1);
	cmp(Instant.MIN, Instant.MIN.getEpochSecond() - 1, SECONDS, 1);
	cmp(Instant.MIN, Instant.MIN.getEpochSecond() - 100, SECONDS, 1);
	cmp(Instant.MIN, Instant.MIN.getEpochSecond(), SECONDS, 0);

	cmp(Instant.MAX, Long.MAX_VALUE, DAYS, -1);
	cmp(Instant.MAX, Long.MAX_VALUE, HOURS, -1);
	cmp(Instant.MAX, Long.MAX_VALUE, MINUTES, -1);
	cmp(Instant.MAX, Long.MAX_VALUE, SECONDS, -1);
	cmp(Instant.MAX, Instant.MAX.getEpochSecond() + 1, SECONDS, -1);
	cmp(Instant.MAX, Instant.MAX.getEpochSecond() + 100, SECONDS, -1);
	cmp(Instant.MAX, Instant.MAX.getEpochSecond(), SECONDS, 0);

	cmp(nowInstant, now, MILLISECONDS, 0);
	cmp(nowInstant, now*1000L, MICROSECONDS, 0);
	cmp(nowInstant, now-1234, MILLISECONDS, 1);
	cmp(nowInstant, now+1234, MILLISECONDS, -1);
	cmp(nowInstant, tomorrowInDays, DAYS, -1);
	cmp(nowInstant, yesterdayInDays, DAYS, 1);

	// to(TimeUnit)
	to(MILLISECONDS.convert(1, DAYS) - 1, MILLISECONDS);
	to(MILLISECONDS.convert(1, DAYS) + 0, MILLISECONDS);
	to(MILLISECONDS.convert(1, DAYS) + 1, MILLISECONDS);
	to(1, MILLISECONDS);
	to(0, MILLISECONDS);
	to(1, MILLISECONDS);
	to(MILLISECONDS.convert(-1, DAYS) - 1, MILLISECONDS);
	to(MILLISECONDS.convert(-1, DAYS) + 0, MILLISECONDS);
	to(MILLISECONDS.convert(-1, DAYS) + 1, MILLISECONDS);
	for (TimeUnit unit: TimeUnit.values()) {
	for (int i=0; i<100; i++) { to(rand.nextLong(), unit); }
	to(Long.MIN_VALUE, unit);
	to(Long.MAX_VALUE, unit);
	}

	// toInstant()
	int N = 1000;
	for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
	for (int i = 0; i < N; i++) {
	long value = rand.nextLong();
	FileTime ft = FileTime.from(value, unit);
	Instant instant = ft.toInstant();
	if (instant != Instant.MIN && instant != Instant.MAX) {
	eqTime(value, unit, instant);
	}
	}
	}
	for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
	long value = Long.MIN_VALUE;
	FileTime ft = FileTime.from(value, unit);
	Instant instant = ft.toInstant();
	if (unit.compareTo(TimeUnit.SECONDS) < 0) {
	eqTime(value, unit, instant);
	} else if (!instant.equals(Instant.MIN)) {
	throw new RuntimeException("should overflow to MIN");
	}
	value = Long.MAX_VALUE;
	ft = FileTime.from(value, unit);
	instant = ft.toInstant();
	if (unit.compareTo(TimeUnit.SECONDS) < 0) {
	eqTime(value, unit, instant);
	} else if (!instant.equals(Instant.MAX)) {
	throw new RuntimeException("should overflow to MAX");
	}
	}

	// from(Instant)
	final long MAX_SECOND = 31556889864403199L;
	for (int i = 0; i < N; i++) {
	long v = rand.nextLong();
	long secs = v % MAX_SECOND;
	Instant instant = Instant.ofEpochSecond(secs, rand.nextInt(1000_000_000));
	FileTime ft = FileTime.from(instant);
	if (!ft.toInstant().equals(instant) \|\| ft.to(SECONDS) != secs) {
	throw new RuntimeException("from(Instant) failed");
	}
	long millis = v;
	instant = Instant.ofEpochMilli(millis);
	ft = FileTime.from(instant);
	if (!ft.toInstant().equals(instant) \|\|
	ft.toMillis() != instant.toEpochMilli()) {
	throw new RuntimeException("from(Instant) failed");
	}
	long nanos = v;
	ft = FileTime.from(nanos, NANOSECONDS);
	secs = nanos / 1000_000_000;
	nanos = nanos % 1000_000_000;
	instant = Instant.ofEpochSecond(secs, nanos);
	if (!ft.equals(FileTime.from(instant))) {
	throw new RuntimeException("from(Instant) failed");
	}
	}

	// toString
	ts(1L, DAYS, "1970-01-02T00:00:00Z");
	ts(1L, HOURS, "1970-01-01T01:00:00Z");
	ts(1L, MINUTES, "1970-01-01T00:01:00Z");
	ts(1L, SECONDS, "1970-01-01T00:00:01Z");
	ts(1L, MILLISECONDS, "1970-01-01T00:00:00.001Z");
	ts(1L, MICROSECONDS, "1970-01-01T00:00:00.000001Z");
	ts(1L, NANOSECONDS, "1970-01-01T00:00:00.000000001Z");
	ts(999999999L, NANOSECONDS, "1970-01-01T00:00:00.999999999Z");
	ts(9999999999L, NANOSECONDS, "1970-01-01T00:00:09.999999999Z");

	ts(-1L, DAYS, "1969-12-31T00:00:00Z");
	ts(-1L, HOURS, "1969-12-31T23:00:00Z");
	ts(-1L, MINUTES, "1969-12-31T23:59:00Z");
	ts(-1L, SECONDS, "1969-12-31T23:59:59Z");
	ts(-1L, MILLISECONDS, "1969-12-31T23:59:59.999Z");
	ts(-1L, MICROSECONDS, "1969-12-31T23:59:59.999999Z");
	ts(-1L, NANOSECONDS, "1969-12-31T23:59:59.999999999Z");
	ts(-999999999L, NANOSECONDS, "1969-12-31T23:59:59.000000001Z");
	ts(-9999999999L, NANOSECONDS, "1969-12-31T23:59:50.000000001Z");

	ts(-62135596799999L, MILLISECONDS, "0001-01-01T00:00:00.001Z");
	ts(-62135596800000L, MILLISECONDS, "0001-01-01T00:00:00Z");
	ts(-62135596800001L, MILLISECONDS, "-0001-12-31T23:59:59.999Z");

	ts(253402300799999L, MILLISECONDS, "9999-12-31T23:59:59.999Z");
	ts(-377642044800001L, MILLISECONDS, "-9999-12-31T23:59:59.999Z");

	// NTFS epoch in usec.
	ts(-11644473600000000L, MICROSECONDS, "1601-01-01T00:00:00Z");

	ts(Instant.MIN, "-1000000001-01-01T00:00:00Z");
	ts(Instant.MAX, "1000000000-12-31T23:59:59.999999999Z");

	try {
	FileTime.from(0L, null);
	throw new RuntimeException("NullPointerException expected");
	} catch (NullPointerException npe) { }
	try {
	FileTime.from(null);
	throw new RuntimeException("NullPointerException expected");
	} catch (NullPointerException npe) { }

	FileTime time = FileTime.fromMillis(now);
	if (time.equals(null))
	throw new RuntimeException("should not be equal to null");
	try {
	time.compareTo(null);
	throw new RuntimeException("NullPointerException expected");
	} catch (NullPointerException npe) { }

	// Instant + toMilli() overflow
	overflow(Long.MAX_VALUE,
	FileTime.from(Instant.MAX).toMillis());
	overflow(Long.MAX_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000 + 1))
	.toMillis());
	overflow(Long.MIN_VALUE,
	FileTime.from(Instant.MIN).toMillis());
	overflow(Long.MIN_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000 - 1))
	.toMillis());

	// Instant + to(TimeUnit) overflow
	overflow(Long.MAX_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000 + 1))
	.to(MILLISECONDS));
	overflow(Long.MAX_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MAX_VALUE / 1000,
	MILLISECONDS.toNanos(1000)))
	.to(MILLISECONDS));
	overflow(Long.MIN_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000 - 1))
	.to(MILLISECONDS));
	overflow(Long.MIN_VALUE,
	FileTime.from(Instant.ofEpochSecond(Long.MIN_VALUE / 1000,
	-MILLISECONDS.toNanos(1)))
	.to(MILLISECONDS));
	}

	static void overflow(long minmax, long v) {
	if (v != minmax)
	throw new RuntimeException("saturates to Long.MIN/MAX_VALUE expected");
	}

	static void cmp(long v1, TimeUnit u1, long v2, TimeUnit u2, int expected) {
	int result = FileTime.from(v1, u1).compareTo(FileTime.from(v2, u2));
	if (result != expected)
	throw new RuntimeException("unexpected order");
	}

	static void cmp(Instant ins, long v2, TimeUnit u2, int expected) {
	int result = FileTime.from(ins).compareTo(FileTime.from(v2, u2));
	if (result != expected)
	throw new RuntimeException("unexpected order");
	}

	static void eq(long v1, TimeUnit u1, long v2, TimeUnit u2) {
	FileTime t1 = FileTime.from(v1, u1);
	FileTime t2 = FileTime.from(v2, u2);
	if (!t1.equals(t2))
	throw new RuntimeException("not equal");
	if (t1.hashCode() != t2.hashCode())
	throw new RuntimeException("hashCodes should be equal");
	}

	static void eq(Instant ins, long v2, TimeUnit u2) {
	FileTime t1 = FileTime.from(ins);
	FileTime t2 = FileTime.from(v2, u2);
	if (!t1.equals(t2))
	throw new RuntimeException("not equal");
	if (t1.hashCode() != t2.hashCode())
	throw new RuntimeException("hashCodes should be equal");
	}

	static void eqTime(long value, TimeUnit unit, Instant instant) {
	long secs = SECONDS.convert(value, unit);
	long nanos = NANOSECONDS.convert(value - unit.convert(secs, SECONDS), unit);
	if (nanos < 0) { // normalize nanoOfSecond to positive
	secs -= 1;
	nanos += 1000_000_000;
	}
	if (secs != instant.getEpochSecond() \|\| (int)nanos != instant.getNano()) {
	System.err.println(" ins=" + instant);
	throw new RuntimeException("ft and instant are not the same time point");
	}
	}

	static void neq(long v1, TimeUnit u1, long v2, TimeUnit u2) {
	FileTime t1 = FileTime.from(v1, u1);
	FileTime t2 = FileTime.from(v2, u2);
	if (t1.equals(t2))
	throw new RuntimeException("should not be equal");
	}

	static void neq(Instant ins, long v2, TimeUnit u2) {
	FileTime t1 = FileTime.from(ins);
	FileTime t2 = FileTime.from(v2, u2);
	if (t1.equals(t2))
	throw new RuntimeException("should not be equal");
	}

	static void to(long v, TimeUnit unit) {
	FileTime t = FileTime.from(v, unit);
	for (TimeUnit u: TimeUnit.values()) {
	long result = t.to(u);
	long expected = u.convert(v, unit);
	if (result != expected) {
	throw new RuntimeException("unexpected result");
	}
	}
	}

	static void ts(long v, TimeUnit unit, String expected) {
	String result = FileTime.from(v, unit).toString();
	if (!result.equals(expected)) {
	System.err.format("FileTime.from(%d, %s).toString() failed\n", v, unit);
	System.err.format("Expected: %s\n", expected);
	System.err.format(" Got: %s\n", result);
	throw new RuntimeException();
	}
	}

	static void ts(Instant instant, String expected) {
	String result = FileTime.from(instant).toString();
	if (!result.equals(expected)) {
	System.err.format("FileTime.from(%s).toString() failed\n", instant);
	System.err.format("Expected: %s\n", expected);
	System.err.format(" Got: %s\n", result);
	throw new RuntimeException();
	}
	}
	}