mutableinteger.java

Standord Classifier实现了一个基于Java的最大熵分类器。用于模式识别

package edu.stanford.nlp.util;

/** A class for Integer objects that you can change.
 *  @author Dan Klein
 */
public final class MutableInteger extends Number implements Comparable {

  private int i;

  // Mutable
  public void set(int i) { this.i = i; }
  public int hashCode() { return i; }

  /**
   * Compares this object to the specified object.  The result is
   * <code>true</code> if and only if the argument is not
   * <code>null</code> and is an <code>MutableInteger</code> object that
   * contains the same <code>int</code> value as this object.
   * Note that a MutableInteger isn't and can't be equal to an Integer.
   *
   * @param   obj   the object to compare with.
   * @return  <code>true</code> if the objects are the same;
   *          <code>false</code> otherwise.
   */
  public boolean equals(Object obj) {
    if (obj instanceof MutableInteger) {
      return i == ((MutableInteger)obj).i;
    }
    return false;
  }

  public String toString() {
    return Integer.toString(i);
  }

  // Comparable interface

  /**
   * Compares two <code>MutableInteger</code> objects numerically.
   *
   * @param   anotherMutableInteger   the <code>MutableInteger</code> to be
   *      compared.
   * @return Tthe value <code>0</code> if this <code>MutableInteger</code> is
   * equal to the argument <code>MutableInteger</code>; a value less than
   * <code>0</code> if this <code>MutableInteger</code> is numerically less
   * than the argument <code>MutableInteger</code>; and a value greater 
   * than <code>0</code> if this <code>MutableInteger</code> is numerically
   * greater than the argument <code>MutableInteger</code> (signed
   * comparison).
   */
  public int compareTo(MutableInteger anotherMutableInteger) {
    int thisVal = this.i;
    int anotherVal = anotherMutableInteger.i;
    return (thisVal<anotherVal ? -1 : (thisVal==anotherVal ? 0 : 1));
  }

  /**
   * Compares this <code>MutableInteger</code> object to another object.
   * If the object is an <code>MutableInteger</code>, this function behaves
   * like <code>compareTo(MutableInteger)</code>.  Otherwise, it throws a
   * <code>ClassCastException</code> (as <code>MutableInteger</code>
   * objects are only comparable to other <code>MutableInteger</code>
   * objects).
   *
   * @param   o the <code>Object</code> to be compared.
   * @return  0/-1/1
   * @exception <code>ClassCastException</code> if the argument is not an
   *  <code>MutableInteger</code>.
   * @see     java.lang.Comparable
   */
  public int compareTo(Object o) {
    return compareTo((MutableInteger)o);
  }

  // Number interface
  public int intValue() { return i; }
  public long longValue() { return (long)i; }
  public short shortValue() { return (short)i; }
  public byte byteValue() { return (byte)i; }
  public float floatValue() { return (float)i; }
  public double doubleValue() { return (double)i; }

  public MutableInteger() { this(0); }
  public MutableInteger(int i) { this.i=i; }

  private static final long serialVersionUID = 624465615824626762L;
}