code: /*
   * 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>NumberRange</code> represents an inclusive range of 
   * {@link java.lang.Number} objects of the same type.</p>
   *
   * @author <a href="mailto:chrise@esha.com">Christopher Elkins</a>
   * @author Stephen Colebourne
   * @since 2.0 (previously in org.apache.commons.lang)
   * @version $Id: NumberRange.java 437554 2006-08-28 06:21:41Z bayard $
   */
  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;
  
      /**
       * <p>Constructs a new <code>NumberRange</code> using the specified
       * number as both the minimum and maximum in this range.</p>
       *
       * @param num the number to use for this range
       * @throws IllegalArgumentException if the number is <code>null</code>
       * @throws IllegalArgumentException if the number doesn't implement <code>Comparable</code>
       * @throws IllegalArgumentException if the number is <code>Double.NaN</code> or <code>Float.NaN</code>
       */
      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;
      }
  
      /**
       * <p>Constructs a new <code>NumberRange</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
       * {@link #getMinimumNumber()} and {@link #getMaximumNumber()} methods will return the
       * correct value.</p>
       * 
       * <p>This constructor is designed to be used with two <code>Number</code>
       * objects of the same type. If two objects of different types are passed in,
       * an exception is thrown.</p>
       *
       * @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 <code>null</code>
       * @throws IllegalArgumentException if the numbers are of different types
       * @throws IllegalArgumentException if the numbers don't implement <code>Comparable</code>
       */
      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
      //--------------------------------------------------------------------
  
      /**
       * <p>Returns the minimum number in this range.</p>
       *
       * @return the minimum number in this range
       */
      public Number getMinimumNumber() {
          return min;
      }
  
      /**
       * <p>Returns the maximum number in this range.</p>
       *
       * @return the maximum number in this range
       */
      public Number getMaximumNumber() {
          return max;
      }
  
      // Tests
      //--------------------------------------------------------------------
      
      /**
       * <p>Tests whether the specified <code>number</code> occurs within
       * this range.</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
       * @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
      //--------------------------------------------------------------------
  
      /**
       * <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 NumberRange == false) {
              return false;
          }
          NumberRange range = (NumberRange) obj;
          return min.equals(range.min) && max.equals(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();
              hashCode = 37 * hashCode + min.hashCode();
              hashCode = 37 * hashCode + max.hashCode();
          }
          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;
      }
  
  }
  