org.apache.commons.lang.math.NumberRange Maven / Gradle / Ivy
/*
* 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 org.apache.commons.lang.math;
import java.io.Serializable;
import org.apache.commons.lang.text.StrBuilder;
/**
* NumberRange represents an inclusive range of
* {@link java.lang.Number} objects of the same type.
*
* @author Apache Software Foundation
* @author Christopher Elkins
* @since 2.0 (previously in org.apache.commons.lang)
* @version $Id: NumberRange.java 1057072 2011-01-10 01:55:57Z niallp $
*/
public final class NumberRange extends Range implements Serializable {
/**
* Required for serialization support.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = 71849363892710L;
/**
* The minimum number in this range.
*/
private final Number min;
/**
* The maximum number in this range.
*/
private final Number max;
/**
* Cached output hashCode (class is immutable).
*/
private transient int hashCode = 0;
/**
* Cached output toString (class is immutable).
*/
private transient String toString = null;
/**
* Constructs a new NumberRange using the specified
* number as both the minimum and maximum in this range.
*
* @param num the number to use for this range
* @throws IllegalArgumentException if the number is null
* @throws IllegalArgumentException if the number doesn't implement Comparable
* @throws IllegalArgumentException if the number is Double.NaN or Float.NaN
*/
public NumberRange(Number num) {
if (num == null) {
throw new IllegalArgumentException("The number must not be null");
}
if (num instanceof Comparable == false) {
throw new IllegalArgumentException("The number must implement Comparable");
}
if (num instanceof Double && ((Double) num).isNaN()) {
throw new IllegalArgumentException("The number must not be NaN");
}
if (num instanceof Float && ((Float) num).isNaN()) {
throw new IllegalArgumentException("The number must not be NaN");
}
this.min = num;
this.max = num;
}
/**
* Constructs a new NumberRange with the specified
* minimum and maximum numbers (both inclusive).
*
* The arguments may be passed in the order (min,max) or (max,min). The
* {@link #getMinimumNumber()} and {@link #getMaximumNumber()} methods will return the
* correct value.
*
* This constructor is designed to be used with two Number
* objects of the same type. If two objects of different types are passed in,
* an exception is thrown.
*
* @param num1 first number that defines the edge of the range, inclusive
* @param num2 second number that defines the edge of the range, inclusive
* @throws IllegalArgumentException if either number is null
* @throws IllegalArgumentException if the numbers are of different types
* @throws IllegalArgumentException if the numbers don't implement Comparable
*/
public NumberRange(Number num1, Number num2) {
if (num1 == null || num2 == null) {
throw new IllegalArgumentException("The numbers must not be null");
}
if (num1.getClass() != num2.getClass()) {
throw new IllegalArgumentException("The numbers must be of the same type");
}
if (num1 instanceof Comparable == false) {
throw new IllegalArgumentException("The numbers must implement Comparable");
}
if (num1 instanceof Double) {
if (((Double) num1).isNaN() || ((Double) num2).isNaN()) {
throw new IllegalArgumentException("The number must not be NaN");
}
} else if (num1 instanceof Float) {
if (((Float) num1).isNaN() || ((Float) num2).isNaN()) {
throw new IllegalArgumentException("The number must not be NaN");
}
}
int compare = ((Comparable) num1).compareTo(num2);
if (compare == 0) {
this.min = num1;
this.max = num1;
} else if (compare > 0) {
this.min = num2;
this.max = num1;
} else {
this.min = num1;
this.max = num2;
}
}
// Accessors
//--------------------------------------------------------------------
/**
* Returns the minimum number in this range.
*
* @return the minimum number in this range
*/
public Number getMinimumNumber() {
return min;
}
/**
* Returns the maximum number in this range.
*
* @return the maximum number in this range
*/
public Number getMaximumNumber() {
return max;
}
// Tests
//--------------------------------------------------------------------
/**
* Tests whether the specified number occurs within
* this range.
*
* null is handled and returns false.
*
* @param number the number to test, may be null
* @return true if the specified number occurs within this range
* @throws IllegalArgumentException if the number is of a different type to the range
*/
public boolean containsNumber(Number number) {
if (number == null) {
return false;
}
if (number.getClass() != min.getClass()) {
throw new IllegalArgumentException("The number must be of the same type as the range numbers");
}
int compareMin = ((Comparable) min).compareTo(number);
int compareMax = ((Comparable) max).compareTo(number);
return compareMin <= 0 && compareMax >= 0;
}
// Range tests
//--------------------------------------------------------------------
// use Range implementations
// Basics
//--------------------------------------------------------------------
/**
* Compares this range to another object to test if they are equal.
.
*
* To be equal, the class, minimum and maximum must be equal.
*
* @param obj the reference object with which to compare
* @return true if this object is equal
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof NumberRange == false) {
return false;
}
NumberRange range = (NumberRange) obj;
return min.equals(range.min) && max.equals(range.max);
}
/**
* Gets a hashCode for the range.
*
* @return a hash code value for this object
*/
public int hashCode() {
if (hashCode == 0) {
hashCode = 17;
hashCode = 37 * hashCode + getClass().hashCode();
hashCode = 37 * hashCode + min.hashCode();
hashCode = 37 * hashCode + max.hashCode();
}
return hashCode;
}
/**
* Gets the range as a String.
*
* The format of the String is 'Range[min,max]'.
*
* @return the String representation of this range
*/
public String toString() {
if (toString == null) {
StrBuilder buf = new StrBuilder(32);
buf.append("Range[");
buf.append(min);
buf.append(',');
buf.append(max);
buf.append(']');
toString = buf.toString();
}
return toString;
}
}