Java tutorial
/* * Copyright (c) 2015 Spotify AB. * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.spotify.heroic.common; import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonIgnore; import com.fasterxml.jackson.annotation.JsonProperty; import com.spotify.heroic.ObjectHasher; import com.spotify.heroic.time.Clock; import eu.toolchain.serializer.AutoSerialize; import lombok.Data; import lombok.EqualsAndHashCode; import org.apache.commons.lang3.time.FastDateFormat; import java.sql.Date; import static com.google.common.base.Preconditions.checkArgument; @AutoSerialize @Data @EqualsAndHashCode(of = { "start", "end" }) public class DateRange implements Comparable<DateRange> { private static final FastDateFormat FORMAT = FastDateFormat.getInstance("yyyy-MM-dd HH:mm:ss.SSS"); private final long start; private final long end; public DateRange(long start, long end) { checkArgument(start >= 0, "start must be a positive number"); if (end < start) { throw new IllegalArgumentException(String.format("start (%d) must come before end (%d)", start, end)); } this.start = start; this.end = end; } public long start() { return start; } public long end() { return end; } @JsonIgnore public boolean isEmpty() { return diff() == 0; } @JsonIgnore public boolean isNotEmpty() { return !isEmpty(); } public long diff() { return end - start; } /** * Creates a range that is rounded to the specified interval. * * @param interval Interval to round to. Return same range if 0. * @return Rounded date range. */ public DateRange rounded(long interval) { if (interval <= 0) { return this; } return new DateRange(start - start % interval, end - (end % interval)); } public boolean overlap(DateRange other) { if (end < other.start) { return false; } if (start > other.end) { return false; } return true; } @Override public int compareTo(DateRange other) { return Long.compare(start, other.start); } public DateRange join(DateRange other) { long start = Math.min(this.start, other.start); long end = Math.max(this.end, other.end); return new DateRange(start, end); } public boolean contains(long t) { return t >= start && t <= end; } /** * Modify this range with another range. * <p> * A modification asserts that the new range is a subset of the current range. Any span which * would cause the new range to become out of bounds will be cropped. * * @param range The constraints to modify this range against. * @return A new range representing the modified range. */ public DateRange modify(DateRange range) { return modify(range.getStart(), range.getEnd()); } /** * Modify the date range so that it fits within the given range (start - end). * * @param start Start value to fit this range into. * @param end End value (exclusive) to fit this range into. * @return A modified date range that fits within the given range. */ public DateRange modify(long start, long end) { return new DateRange(Math.max(this.start, start), Math.min(this.end, end - 1)); } public DateRange start(long start) { return new DateRange(start, this.end); } public DateRange end(long end) { return new DateRange(this.start, end); } public DateRange shift(long extent) { return new DateRange(Math.max(start + extent, 0), Math.max(end + extent, 0)); } @Override public String toString() { final Date start = new Date(this.start); final Date end = new Date(this.end); return "{" + FORMAT.format(start) + "}-{" + FORMAT.format(end) + "}"; } @JsonCreator public static DateRange create(@JsonProperty(value = "start", required = true) Long start, @JsonProperty(value = "end", required = true) Long end) { return new DateRange(start, end); } public static DateRange now(long now) { return new DateRange(now, now); } public static DateRange now(Clock clock) { return now(clock.currentTimeMillis()); } public void hashTo(final ObjectHasher hasher) { hasher.putObject(getClass(), () -> { hasher.putField("start", start, hasher.longValue()); hasher.putField("end", end, hasher.longValue()); }); } }