|
/*
* 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.
*/
/**
* <p>Represents a range of {@link Number} objects.</p>
*
* <p>This class uses <code>double</code> comparisons. This means that it
* is unsuitable for dealing with large <code>Long</code>, <code>BigDecimal</code>
* or <code>BigInteger</code> numbers.</p>
*
* @author <a href="mailto:chrise@esha.com">Christopher Elkins</a>
* @author Stephen Colebourne
* @since 1.0
* @version $Revision: 437554 $ $Date: 2006-08-27 23:21:41 -0700 (Sun, 27 Aug 2006) $
*
*
*/
public final class NumberRange {
/* The minimum number in this range. */
private final Number min;
/* The maximum number in this range. */
private final Number max;
/**
* <p>Constructs a new <code>NumberRange</code> using
* <code>number</code> as both the minimum and maximum in
* this range.</p>
*
* @param num the number to use for this range
* @throws NullPointerException if the number is <code>null</code>
*/
public NumberRange(Number num) {
if (num == null) {
throw new NullPointerException("The number must not be null");
}
this.min = num;
this.max = num;
}
/**
* <p>Constructs a new <code>NumberRange</code> with the specified
* minimum and maximum numbers.</p>
*
* <p><em>If the maximum is less than the minimum, the range will be constructed
* from the minimum value to the minimum value, not what you would expect!.</em></p>
*
* @param min the minimum number in this range
* @param max the maximum number in this range
* @throws NullPointerException if either the minimum or maximum number is
* <code>null</code>
*/
public NumberRange(Number min, Number max) {
if (min == null) {
throw new NullPointerException("The minimum value must not be null");
} else if (max == null) {
throw new NullPointerException("The maximum value must not be null");
}
if (max.doubleValue() < min.doubleValue()) {
this.min = this.max = min;
} else {
this.min = min;
this.max = max;
}
}
/**
* <p>Returns the minimum number in this range.</p>
*
* @return the minimum number in this range
*/
public Number getMinimum() {
return min;
}
/**
* <p>Returns the maximum number in this range.</p>
*
* @return the maximum number in this range
*/
public Number getMaximum() {
return max;
}
/**
* <p>Tests whether the specified <code>number</code> occurs within
* this range using <code>double</code> comparison.</p>
*
* @param number the number to test
* @return <code>true</code> if the specified number occurs within this
* range; otherwise, <code>false</code>
*/
public boolean includesNumber(Number number) {
if (number == null) {
return false;
} else {
return !(min.doubleValue() > number.doubleValue()) &&
!(max.doubleValue() < number.doubleValue());
}
}
/**
* <p>Tests whether the specified range occurs entirely within this
* range using <code>double</code> comparison.</p>
*
* @param range the range to test
* @return <code>true</code> if the specified range occurs entirely within
* this range; otherwise, <code>false</code>
*/
public boolean includesRange(NumberRange range) {
if (range == null) {
return false;
} else {
return includesNumber(range.min) && includesNumber(range.max);
}
}
/**
* <p>Tests whether the specified range overlaps with this range
* using <code>double</code> comparison.</p>
*
* @param range the range to test
* @return <code>true</code> if the specified range overlaps with this
* range; otherwise, <code>false</code>
*/
public boolean overlaps(NumberRange range) {
if (range == null) {
return false;
} else {
return range.includesNumber(min) || range.includesNumber(max) ||
includesRange(range);
}
}
/**
* <p>Indicates whether some other <code>Object</code> is
* "equal" to this one.</p>
*
* @param obj the reference object with which to compare
* @return <code>true</code> if this object is the same as the obj
* argument; <code>false</code> otherwise
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
} else if (!(obj instanceof NumberRange)) {
return false;
} else {
NumberRange range = (NumberRange)obj;
return min.equals(range.min) && max.equals(range.max);
}
}
/**
* <p>Returns a hash code value for this object.</p>
*
* @return a hash code value for this object
*/
public int hashCode() {
int result = 17;
result = 37 * result + min.hashCode();
result = 37 * result + max.hashCode();
return result;
}
/**
* <p>Returns the string representation of this range.</p>
*
* <p>This string is the string representation of the minimum and
* maximum numbers in the range, separated by a hyphen. If a number
* is negative, then it is enclosed in parentheses.</p>
*
* @return the string representation of this range
*/
public String toString() {
StringBuffer sb = new StringBuffer();
if (min.doubleValue() < 0) {
sb.append('(')
.append(min)
.append(')');
} else {
sb.append(min);
}
sb.append('-');
if (max.doubleValue() < 0) {
sb.append('(')
.append(max)
.append(')');
} else {
sb.append(max);
}
return sb.toString();
}
}
|