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Protempa Framework is the core of Protempa.
/*
* #%L
* Protempa Framework
* %%
* Copyright (C) 2012 - 2013 Emory University
* %%
* 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.
* #L%
*/
package org.protempa.proposition.value;
import org.apache.commons.collections4.map.ReferenceMap;
import org.apache.commons.lang3.builder.ToStringBuilder;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.text.Format;
import java.util.Date;
import java.util.Map;
/**
* Represents dates and datetimes.
*
* @author Andrew Post
*/
public class DateValue implements OrderedValue, Comparable,
Serializable {
private static final AbsoluteTimeGranularity gran
= AbsoluteTimeGranularity.DAY;
private static final Map cache = new ReferenceMap<>();
private static final long serialVersionUID = 7939358587048726659L;
/**
* Parses a date from a string. Expects the format used by
* {@link AbsoluteTimeGranularity#DAY}'s getShortFormat().
*
* @param str a string representing a date.
* @return a date value, or null if no date could be parsed.
*/
public static DateValue parse(String str) {
return (DateValue) ValueType.DATEVALUE.parse(str);
}
/**
* Constructs a new date value from a Java date object. Uses a cache to
* reuse date value objects.
*
* @param date a {@link Date}. If null a new date value is
* created using the current time.
*
* @return a {@link DateValue}.
*/
public static DateValue getInstance(Date date) {
DateValue result;
if (date != null) {
synchronized (cache) {
result = cache.get(date);
if (result == null) {
result = new DateValue(date);
cache.put(date, result);
}
}
} else {
result = getInstance(new Date());
}
return result;
}
/**
* Constructs a new date value representing the current time.
*
* @return a {@link DateValue}.
*/
public static DateValue getInstance() {
return getInstance(null);
}
private Date date;
/**
* Constructs a new date value object representing the current time. Use
* {@link #getInstance() } instead to leverage a cache of frequently used
* date values.
*
* @return a {@link DateValue}.
*/
public DateValue() {
init(null);
}
/**
* Constructs a new date value from a Java date object. Use
* {@link #getInstance(Date) } instead to leverage a cache of frequently
* used date values.
*
* @return a {@link DateValue}.
*/
public DateValue(Date date) {
init(date);
}
private void init(Date date) {
if (date == null) {
date = new Date();
}
this.date = date;
}
/**
* Gets the date represented by this object as a Java {@link Date}.
*
* @return a {@link Date}.
*/
public Date getDate() {
return this.date;
}
@Override
public String getFormatted() {
return gran.getShortFormat().format(this.date);
}
/**
* Formats this date value with a custom {@link Format}. This method
* passes the format a {@link Date} object.
*
* @param format the custom format.
* @return a formatted date string.
*/
@Override
public String format(Format format) {
if (format == null) {
return getFormatted();
} else {
return format.format(this.date);
}
}
@Override
public ValueType getType() {
return ValueType.DATEVALUE;
}
/**
* Compares this date value and another date value according to their
* natural order, or checks this date value for membership in a value list.
*
* @param o a {@link Value}.
* @return {@link ValueComparator#GREATER_THAN},
* {@link ValueComparator#LESS_THAN} or {@link ValueComparator#EQUAL_TO}
* depending on whether this value is greater than, less than or equal to
* the value provided as argument. If the provided value is a value list,
* returns {@link ValueComparator#IN} if this date value is in the list, or
* {@link ValueComparator#NOT_IN} if this date value is not in the list.
* Otherwise, returns {@link ValueComparator#UNKNOWN}.
*/
@Override
public ValueComparator compare(Value o) {
if (o == null) {
return ValueComparator.NOT_EQUAL_TO;
}
switch (o.getType()) {
case DATEVALUE:
DateValue other = (DateValue) o;
int comp = compareTo(other);
return comp > 0 ? ValueComparator.GREATER_THAN
: (comp < 0 ? ValueComparator.LESS_THAN
: ValueComparator.EQUAL_TO);
case VALUELIST:
ValueList vl = (ValueList) o;
return vl.contains(this) ? ValueComparator.IN : ValueComparator.NOT_IN;
default:
return ValueComparator.NOT_EQUAL_TO;
}
}
@Override
public Value replace() {
DateValue result;
synchronized (cache) {
result = cache.get(this.date);
}
if (result != null) {
return result;
} else {
return this;
}
}
@Override
public void accept(ValueVisitor valueVisitor) {
if (valueVisitor == null) {
throw new IllegalArgumentException("valueVisitor cannot be null");
}
valueVisitor.visit(this);
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
@Override
public int compareTo(DateValue other) {
return this.date.compareTo(other.date);
}
private void writeObject(ObjectOutputStream s) throws IOException {
s.writeObject(this.date);
}
private void readObject(ObjectInputStream s) throws IOException,
ClassNotFoundException {
Date tmpDate = (Date) s.readObject();
init(tmpDate);
if (!cache.containsKey(tmpDate)) {
cache.put(tmpDate, this);
}
}
@Override
public int hashCode() {
return (date == null) ? 0 : date.hashCode();
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
DateValue other = (DateValue) obj;
if (date == null) {
if (other.date != null) {
return false;
}
} else if (!date.equals(other.date)) {
return false;
}
return true;
}
@Override
public DateValueBuilder asBuilder() {
return new DateValueBuilder(this);
}
}