com.wealdtech.utils.WealdInterval.java Source code

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Here is the source code for com.wealdtech.utils.WealdInterval.java

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/*
 * Copyright 2012 - 2014 Weald Technology Trading Limited
 *
 * 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.wealdtech.utils;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Objects;
import com.google.common.collect.ComparisonChain;
import com.google.common.collect.Range;
import org.joda.time.DateTime;
import org.joda.time.Duration;
import org.joda.time.Interval;
import org.joda.time.Period;

import static com.wealdtech.Preconditions.checkNotNull;
import static com.wealdtech.Preconditions.checkState;

/**
 * A WealdInterval is similar to a Joda {@link org.joda.time.Interval} except that it retains the timezones of both the start and
 * the end times.  It also implements {@link Comparable} as per {@link IntervalOrdering}.
 * <p/>
 * A WealdInterval is considered to be a closed-open range, and as such the end must be after the start.
 */
public class WealdInterval implements Comparable<WealdInterval> {
    private final transient DateTime start;
    private final transient DateTime end;

    @JsonCreator
    public WealdInterval(@JsonProperty("start") final DateTime start, @JsonProperty("end") final DateTime end) {
        this.start = start;
        this.end = end;
        validate();
    }

    public WealdInterval(final DateTime start, final Duration duration) {
        this.start = start;
        this.end = start.plus(duration);
    }

    public WealdInterval(final DateTime start, final Period period) {
        this.start = start;
        this.end = start.plus(period);
    }

    public static WealdInterval fromRange(final Range<DateTime> range) {
        return new WealdInterval(range.lowerEndpoint(), range.upperEndpoint());
    }

    private void validate() {
        checkNotNull(start, "Start must be specified");
        checkNotNull(end, "End must be specified");
        checkState(!end.isBefore(start), "End cannot be before start");
    }

    public DateTime getStart() {
        return this.start;
    }

    public DateTime getEnd() {
        return this.end;
    }

    /**
     * Obtain a Joda {@link Interval} from this Weald interval.
     * <p/>
     * <b>N.B.</b>
     * This loses information about the timezone in which the end datetime resides so should be used with caution.
     * @return A Joda interval
     */
    @JsonIgnore
    public Interval getInterval() {
        return new Interval(this.start, this.end);
    }

    public Range<DateTime> toRange() {
        return Range.closedOpen(this.start, this.end);
    }

    // Standard object methods follow
    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("start", this.start).add("end", this.end).toString();
    }

    @Override
    public boolean equals(final Object that) {
        return that instanceof WealdInterval && this.compareTo((WealdInterval) that) == 0;
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(this.start, this.end);
    }

    public int compareTo(final WealdInterval that) {
        return ComparisonChain.start().compare(this.getInterval(), that.getInterval(), IntervalOrdering.INSTANCE)
                .result();
    }
}