Java tutorial
/* * 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; /** * <p><code>DoubleRange</code> represents an inclusive range of <code>double</code>s.</p> * * @author Stephen Colebourne * @since 2.0 * @version $Id: DoubleRange.java 437554 2006-08-28 06:21:41Z bayard $ */ public final class DoubleRange extends Range implements Serializable { /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 71849363892740L; /** * The minimum number in this range (inclusive). */ private final double min; /** * The maximum number in this range (inclusive). */ private final double max; /** * Cached output minObject (class is immutable). */ private transient Double minObject = null; /** * Cached output maxObject (class is immutable). */ private transient Double maxObject = null; /** * Cached output hashCode (class is immutable). */ private transient int hashCode = 0; /** * Cached output toString (class is immutable). */ private transient String toString = null; /** * <p>Constructs a new <code>DoubleRange</code> using the specified * number as both the minimum and maximum in this range.</p> * * @param number the number to use for this range * @throws IllegalArgumentException if the number is <code>NaN</code> */ public DoubleRange(double number) { super(); if (Double.isNaN(number)) { throw new IllegalArgumentException("The number must not be NaN"); } this.min = number; this.max = number; } /** * <p>Constructs a new <code>DoubleRange</code> using the specified * number as both the minimum and maximum in this range.</p> * * @param number the number to use for this range, must not * be <code>null</code> * @throws IllegalArgumentException if the number is <code>null</code> * @throws IllegalArgumentException if the number is <code>NaN</code> */ public DoubleRange(Number number) { super(); if (number == null) { throw new IllegalArgumentException("The number must not be null"); } this.min = number.doubleValue(); this.max = number.doubleValue(); if (Double.isNaN(min) || Double.isNaN(max)) { throw new IllegalArgumentException("The number must not be NaN"); } if (number instanceof Double) { this.minObject = (Double) number; this.maxObject = (Double) number; } } /** * <p>Constructs a new <code>DoubleRange</code> with the specified * minimum and maximum numbers (both inclusive).</p> * * <p>The arguments may be passed in the order (min,max) or (max,min). The * getMinimum and getMaximum methods will return the correct values.</p> * * @param number1 first number that defines the edge of the range, inclusive * @param number2 second number that defines the edge of the range, inclusive * @throws IllegalArgumentException if either number is <code>NaN</code> */ public DoubleRange(double number1, double number2) { super(); if (Double.isNaN(number1) || Double.isNaN(number2)) { throw new IllegalArgumentException("The numbers must not be NaN"); } if (number2 < number1) { this.min = number2; this.max = number1; } else { this.min = number1; this.max = number2; } } /** * <p>Constructs a new <code>DoubleRange</code> with the specified * minimum and maximum numbers (both inclusive).</p> * * <p>The arguments may be passed in the order (min,max) or (max,min). The * getMinimum and getMaximum methods will return the correct values.</p> * * @param number1 first number that defines the edge of the range, inclusive * @param number2 second number that defines the edge of the range, inclusive * @throws IllegalArgumentException if either number is <code>null</code> * @throws IllegalArgumentException if either number is <code>NaN</code> */ public DoubleRange(Number number1, Number number2) { super(); if (number1 == null || number2 == null) { throw new IllegalArgumentException("The numbers must not be null"); } double number1val = number1.doubleValue(); double number2val = number2.doubleValue(); if (Double.isNaN(number1val) || Double.isNaN(number2val)) { throw new IllegalArgumentException("The numbers must not be NaN"); } if (number2val < number1val) { this.min = number2val; this.max = number1val; if (number2 instanceof Double) { this.minObject = (Double) number2; } if (number1 instanceof Double) { this.maxObject = (Double) number1; } } else { this.min = number1val; this.max = number2val; if (number1 instanceof Double) { this.minObject = (Double) number1; } if (number2 instanceof Double) { this.maxObject = (Double) number2; } } } // Accessors //-------------------------------------------------------------------- /** * <p>Returns the minimum number in this range.</p> * * @return the minimum number in this range */ public Number getMinimumNumber() { if (minObject == null) { minObject = new Double(min); } return minObject; } /** * <p>Gets the minimum number in this range as a <code>long</code>.</p> * * <p>This conversion can lose information for large values or decimals.</p> * * @return the minimum number in this range */ public long getMinimumLong() { return (long) min; } /** * <p>Gets the minimum number in this range as a <code>int</code>.</p> * * <p>This conversion can lose information for large values or decimals.</p> * * @return the minimum number in this range */ public int getMinimumInteger() { return (int) min; } /** * <p>Gets the minimum number in this range as a <code>double</code>.</p> * * @return the minimum number in this range */ public double getMinimumDouble() { return min; } /** * <p>Gets the minimum number in this range as a <code>float</code>.</p> * * <p>This conversion can lose information for large values.</p> * * @return the minimum number in this range */ public float getMinimumFloat() { return (float) min; } /** * <p>Returns the maximum number in this range.</p> * * @return the maximum number in this range */ public Number getMaximumNumber() { if (maxObject == null) { maxObject = new Double(max); } return maxObject; } /** * <p>Gets the maximum number in this range as a <code>long</code>.</p> * * <p>This conversion can lose information for large values or decimals.</p> * * @return the maximum number in this range */ public long getMaximumLong() { return (long) max; } /** * <p>Gets the maximum number in this range as a <code>int</code>.</p> * * <p>This conversion can lose information for large values or decimals.</p> * * @return the maximum number in this range */ public int getMaximumInteger() { return (int) max; } /** * <p>Gets the maximum number in this range as a <code>double</code>.</p> * * @return the maximum number in this range */ public double getMaximumDouble() { return max; } /** * <p>Gets the maximum number in this range as a <code>float</code>.</p> * * <p>This conversion can lose information for large values.</p> * * @return the maximum number in this range */ public float getMaximumFloat() { return (float) max; } // Tests //-------------------------------------------------------------------- /** * <p>Tests whether the specified <code>number</code> occurs within * this range using <code>double</code> comparison.</p> * * <p><code>null</code> is handled and returns <code>false</code>.</p> * * @param number the number to test, may be <code>null</code> * @return <code>true</code> if the specified number occurs within this range */ public boolean containsNumber(Number number) { if (number == null) { return false; } return containsDouble(number.doubleValue()); } /** * <p>Tests whether the specified <code>double</code> occurs within * this range using <code>double</code> comparison.</p> * * <p>This implementation overrides the superclass for performance as it is * the most common case.</p> * * @param value the double to test * @return <code>true</code> if the specified number occurs within this * range by <code>double</code> comparison */ public boolean containsDouble(double value) { return value >= min && value <= max; } // Range tests //-------------------------------------------------------------------- /** * <p>Tests whether the specified range occurs entirely within this range * using <code>double</code> comparison.</p> * * <p><code>null</code> is handled and returns <code>false</code>.</p> * * @param range the range to test, may be <code>null</code> * @return <code>true</code> if the specified range occurs entirely within this range * @throws IllegalArgumentException if the range is not of this type */ public boolean containsRange(Range range) { if (range == null) { return false; } return containsDouble(range.getMinimumDouble()) && containsDouble(range.getMaximumDouble()); } /** * <p>Tests whether the specified range overlaps with this range * using <code>double</code> comparison.</p> * * <p><code>null</code> is handled and returns <code>false</code>.</p> * * @param range the range to test, may be <code>null</code> * @return <code>true</code> if the specified range overlaps with this range */ public boolean overlapsRange(Range range) { if (range == null) { return false; } return range.containsDouble(min) || range.containsDouble(max) || containsDouble(range.getMinimumDouble()); } // Basics //-------------------------------------------------------------------- /** * <p>Compares this range to another object to test if they are equal.</p>. * * <p>To be equal, the class, minimum and maximum must be equal.</p> * * @param obj the reference object with which to compare * @return <code>true</code> if this object is equal */ public boolean equals(Object obj) { if (obj == this) { return true; } if (obj instanceof DoubleRange == false) { return false; } DoubleRange range = (DoubleRange) obj; return (Double.doubleToLongBits(min) == Double.doubleToLongBits(range.min) && Double.doubleToLongBits(max) == Double.doubleToLongBits(range.max)); } /** * <p>Gets a hashCode for the range.</p> * * @return a hash code value for this object */ public int hashCode() { if (hashCode == 0) { hashCode = 17; hashCode = 37 * hashCode + getClass().hashCode(); long lng = Double.doubleToLongBits(min); hashCode = 37 * hashCode + ((int) (lng ^ (lng >> 32))); lng = Double.doubleToLongBits(max); hashCode = 37 * hashCode + ((int) (lng ^ (lng >> 32))); } return hashCode; } /** * <p>Gets the range as a <code>String</code>.</p> * * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p> * * @return the <code>String</code> representation of this range */ public String toString() { if (toString == null) { StringBuffer buf = new StringBuffer(32); buf.append("Range["); buf.append(min); buf.append(','); buf.append(max); buf.append(']'); toString = buf.toString(); } return toString; } }