Java tutorial
/* * Copyright (c) 2014 Hewlett-Packard Development Company, L.P. * * 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 com.hpcloud.util; import java.io.Serializable; import java.util.HashMap; import java.util.Map; import java.util.concurrent.TimeUnit; import java.util.regex.Pattern; import javax.annotation.concurrent.Immutable; import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility; import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.databind.annotation.JsonSerialize; import com.fasterxml.jackson.databind.ser.std.ToStringSerializer; import com.google.common.base.Preconditions; /** * Duration unit, consisting of length and time unit. */ @Immutable @JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, isGetterVisibility = Visibility.NONE) @JsonSerialize(using = ToStringSerializer.class) public class Duration implements Serializable { private static final long serialVersionUID = -2047960773448166416L; /** A duration of Long.MAX_VALUE Days */ public static final Duration INFINITE = new Duration(); static final Pattern PATTERN = Pattern.compile("[\\d]+[\\s]*(" + "ns|nanosecond(s)?|" + "us|microsecond(s)?|" + "ms|millisecond(s)?|" + "s|second(s)?|" + "m|minute(s)?|" + "h|hour(s)?|" + "d|day(s)?" + ')'); private static final Map<String, TimeUnit> SUFFIXES; public final long length; public final TimeUnit timeUnit; public final boolean finite; static { SUFFIXES = new HashMap<String, TimeUnit>(); SUFFIXES.put("ns", TimeUnit.NANOSECONDS); SUFFIXES.put("nanosecond", TimeUnit.NANOSECONDS); SUFFIXES.put("nanoseconds", TimeUnit.NANOSECONDS); SUFFIXES.put("us", TimeUnit.MICROSECONDS); SUFFIXES.put("microsecond", TimeUnit.MICROSECONDS); SUFFIXES.put("microseconds", TimeUnit.MICROSECONDS); SUFFIXES.put("ms", TimeUnit.MILLISECONDS); SUFFIXES.put("millisecond", TimeUnit.MILLISECONDS); SUFFIXES.put("milliseconds", TimeUnit.MILLISECONDS); SUFFIXES.put("s", TimeUnit.SECONDS); SUFFIXES.put("second", TimeUnit.SECONDS); SUFFIXES.put("seconds", TimeUnit.SECONDS); SUFFIXES.put("m", TimeUnit.MINUTES); SUFFIXES.put("minute", TimeUnit.MINUTES); SUFFIXES.put("minutes", TimeUnit.MINUTES); SUFFIXES.put("h", TimeUnit.HOURS); SUFFIXES.put("hour", TimeUnit.HOURS); SUFFIXES.put("hours", TimeUnit.HOURS); SUFFIXES.put("d", TimeUnit.DAYS); SUFFIXES.put("day", TimeUnit.DAYS); SUFFIXES.put("days", TimeUnit.DAYS); } /** Infinite constructor. */ private Duration() { finite = false; this.length = Long.MAX_VALUE; this.timeUnit = TimeUnit.DAYS; } private Duration(long length, TimeUnit timeUnit) { this.length = length; this.timeUnit = Preconditions.checkNotNull(timeUnit); finite = length == Long.MAX_VALUE && TimeUnit.DAYS.equals(timeUnit) ? false : true; } public static Duration days(long count) { return new Duration(count, TimeUnit.DAYS); } public static Duration hours(long count) { return new Duration(count, TimeUnit.HOURS); } public static Duration inf() { return INFINITE; } public static Duration infinite() { return INFINITE; } public static Duration microseconds(long count) { return new Duration(count, TimeUnit.MICROSECONDS); } public static Duration millis(long count) { return new Duration(count, TimeUnit.MILLISECONDS); } public static Duration milliseconds(long count) { return new Duration(count, TimeUnit.MILLISECONDS); } public static Duration mins(long count) { return new Duration(count, TimeUnit.MINUTES); } public static Duration minutes(long count) { return new Duration(count, TimeUnit.MINUTES); } public static Duration nanos(long count) { return new Duration(count, TimeUnit.NANOSECONDS); } public static Duration nanoseconds(long count) { return new Duration(count, TimeUnit.NANOSECONDS); } public static Duration of(long count, TimeUnit unit) { return new Duration(count, unit); } @JsonCreator public static Duration of(String duration) { Preconditions.checkArgument(PATTERN.matcher(duration).matches(), "Invalid duration: %s", duration); int i = 0; for (; i < duration.length(); i++) if (Character.isLetter(duration.charAt(i))) break; String unit = duration.subSequence(0, i).toString().trim(); String dur = duration.subSequence(i, duration.length()).toString(); return new Duration(Long.parseLong(unit), SUFFIXES.get(dur)); } public static Duration seconds(long count) { return new Duration(count, TimeUnit.SECONDS); } public static Duration secs(long count) { return new Duration(count, TimeUnit.SECONDS); } @Override public boolean equals(Object obj) { if (this == obj) return true; if ((obj == null) || (getClass() != obj.getClass())) return false; final Duration duration = (Duration) obj; return (length == duration.length) && (timeUnit == duration.timeUnit); } @Override public int hashCode() { return (31 * (int) (length ^ (length >>> 32))) + timeUnit.hashCode(); } public long toDays() { return TimeUnit.DAYS.convert(length, timeUnit); } public long toHours() { return TimeUnit.HOURS.convert(length, timeUnit); } public long toMicros() { return TimeUnit.MICROSECONDS.convert(length, timeUnit); } public long toMicroseconds() { return TimeUnit.MICROSECONDS.convert(length, timeUnit); } public long toMillis() { return TimeUnit.MILLISECONDS.convert(length, timeUnit); } public long toMilliseconds() { return TimeUnit.MILLISECONDS.convert(length, timeUnit); } public long toMins() { return TimeUnit.MINUTES.convert(length, timeUnit); } public long toMinutes() { return TimeUnit.MINUTES.convert(length, timeUnit); } public long toNanos() { return TimeUnit.NANOSECONDS.convert(length, timeUnit); } public long toNanoseconds() { return TimeUnit.NANOSECONDS.convert(length, timeUnit); } public long toSeconds() { return TimeUnit.SECONDS.convert(length, timeUnit); } public long toSecs() { return TimeUnit.SECONDS.convert(length, timeUnit); } @Override public String toString() { String units = timeUnit.toString().toLowerCase(); if (length == 1) units = units.substring(0, units.length() - 1); return Long.toString(length) + ' ' + units; } }