001    package biweekly.util;
002    
003    import java.util.Date;
004    
005    /*
006     Copyright (c) 2013, Michael Angstadt
007     All rights reserved.
008    
009     Redistribution and use in source and binary forms, with or without
010     modification, are permitted provided that the following conditions are met: 
011    
012     1. Redistributions of source code must retain the above copyright notice, this
013     list of conditions and the following disclaimer. 
014     2. Redistributions in binary form must reproduce the above copyright notice,
015     this list of conditions and the following disclaimer in the documentation
016     and/or other materials provided with the distribution. 
017    
018     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
019     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
020     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
021     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
022     ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
023     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
024     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
025     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
026     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
027     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
028     */
029    
030    /**
031     * A period of time.
032     * @author Michael Angstadt
033     */
034    public final class Period {
035            private final Date startDate;
036            private final Date endDate;
037            private final Duration duration;
038    
039            /**
040             * Creates a new time period.
041             * @param startDate the start date
042             * @param endDate the end date
043             */
044            public Period(Date startDate, Date endDate) {
045                    this.startDate = copy(startDate);
046                    this.endDate = copy(endDate);
047                    duration = null;
048            }
049    
050            /**
051             * Creates a new time period.
052             * @param startDate the start date
053             * @param duration the length of time after the start date
054             */
055            public Period(Date startDate, Duration duration) {
056                    this.startDate = copy(startDate);
057                    this.duration = duration;
058                    endDate = null;
059            }
060    
061            /**
062             * Copies an existing time period.
063             * @param period the period to copy
064             */
065            public Period(Period period) {
066                    this.startDate = period.startDate;
067                    this.endDate = period.endDate;
068                    this.duration = period.duration;
069            }
070    
071            /**
072             * Gets the start date.
073             * @return the start date
074             */
075            public Date getStartDate() {
076                    return copy(startDate);
077            }
078    
079            /**
080             * Gets the end date. This will be null if a duration was defined.
081             * @return the end date or null if not set
082             */
083            public Date getEndDate() {
084                    return copy(endDate);
085            }
086    
087            /**
088             * Gets the length of time after the start date. This will be null if an end
089             * date was defined.
090             * @return the duration or null if not set
091             */
092            public Duration getDuration() {
093                    return duration;
094            }
095    
096            @Override
097            public int hashCode() {
098                    final int prime = 31;
099                    int result = 1;
100                    result = prime * result + ((duration == null) ? 0 : duration.hashCode());
101                    result = prime * result + ((endDate == null) ? 0 : endDate.hashCode());
102                    result = prime * result + ((startDate == null) ? 0 : startDate.hashCode());
103                    return result;
104            }
105    
106            @Override
107            public boolean equals(Object obj) {
108                    if (this == obj)
109                            return true;
110                    if (obj == null)
111                            return false;
112                    if (getClass() != obj.getClass())
113                            return false;
114                    Period other = (Period) obj;
115                    if (duration == null) {
116                            if (other.duration != null)
117                                    return false;
118                    } else if (!duration.equals(other.duration))
119                            return false;
120                    if (endDate == null) {
121                            if (other.endDate != null)
122                                    return false;
123                    } else if (!endDate.equals(other.endDate))
124                            return false;
125                    if (startDate == null) {
126                            if (other.startDate != null)
127                                    return false;
128                    } else if (!startDate.equals(other.startDate))
129                            return false;
130                    return true;
131            }
132    
133            private Date copy(Date date) {
134                    return (date == null) ? null : new Date(date.getTime());
135            }
136    }