A long integer counter class : Debug « Development Class « Java

1. Java
2. Development Class
3. Debug

A long integer counter class

     

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 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

import java.io.Serializable;

/**
 * A long integer counter class.
 * 
 * @version <tt>$Revision: 2800 $</tt>
 * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
 */
public class LongCounter implements Serializable, Cloneable {
  /** The serialVersionUID */
  private static final long serialVersionUID = 1615297462859270139L;

  /** The current count */
  private long count;

  /**
   * Construct a LongCounter with a starting value.
   * 
   * @param count
   *          Starting value for counter.
   */
  public LongCounter(final long count) {
    this.count = count;
  }

  /**
   * Construct a LongCounter.
   */
  public LongCounter() {
  }

  /**
   * Increment the counter. (Optional operation)
   * 
   * @return The incremented value of the counter.
   */
  public long increment() {
    return ++count;
  }

  /**
   * Decrement the counter. (Optional operation)
   * 
   * @return The decremented value of the counter.
   */
  public long decrement() {
    return --count;
  }

  /**
   * Return the current value of the counter.
   * 
   * @return The current value of the counter.
   */
  public long getCount() {
    return count;
  }

  /**
   * Reset the counter to zero. (Optional operation)
   */
  public void reset() {
    this.count = 0;
  }

  /**
   * Check if the given object is equal to this.
   * 
   * @param obj
   *          Object to test equality with.
   * @return True if object is equal to this.
   */
  public boolean equals(final Object obj) {
    if (obj == this)
      return true;

    if (obj != null && obj.getClass() == getClass()) {
      return ((LongCounter) obj).count == count;
    }

    return false;
  }

  /**
   * Return a string representation of this.
   * 
   * @return A string representation of this.
   */
  public String toString() {
    return String.valueOf(count);
  }

  /**
   * Return a cloned copy of this object.
   * 
   * @return A cloned copy of this object.
   */
  public Object clone() {
    try {
      return super.clone();
    } catch (CloneNotSupportedException e) {
      throw new InternalError();
    }
  }

  // ///////////////////////////////////////////////////////////////////////
  // Wrappers //
  // ///////////////////////////////////////////////////////////////////////

  /**
   * Base wrapper class for other wrappers.
   */
  private static class Wrapper extends LongCounter {
    /** The serialVersionUID */
    private static final long serialVersionUID = 6720507617603163762L;

    /** The wrapped counter */
    protected final LongCounter counter;

    public Wrapper(final LongCounter counter) {
      this.counter = counter;
    }

    public long increment() {
      return counter.increment();
    }

    public long decrement() {
      return counter.decrement();
    }

    public long getCount() {
      return counter.getCount();
    }

    public void reset() {
      counter.reset();
    }

    public boolean equals(final Object obj) {
      return counter.equals(obj);
    }

    public String toString() {
      return counter.toString();
    }

    public Object clone() {
      return counter.clone();
    }
  }

  /**
   * Return a synchronized counter.
   * 
   * @param counter
   *          LongCounter to synchronize.
   * @return Synchronized counter.
   */
  public static LongCounter makeSynchronized(final LongCounter counter) {
    return new Wrapper(counter) {
      /** The serialVersionUID */
      private static final long serialVersionUID = 8903330696503363758L;

      public synchronized long increment() {
        return this.counter.increment();
      }

      public synchronized long decrement() {
        return this.counter.decrement();
      }

      public synchronized long getCount() {
        return this.counter.getCount();
      }

      public synchronized void reset() {
        this.counter.reset();
      }

      public synchronized int hashCode() {
        return this.counter.hashCode();
      }

      public synchronized boolean equals(final Object obj) {
        return this.counter.equals(obj);
      }

      public synchronized String toString() {
        return this.counter.toString();
      }

      public synchronized Object clone() {
        return this.counter.clone();
      }
    };
  }

  /**
   * Returns a directional counter.
   * 
   * @param counter
   *          LongCounter to make directional.
   * @param increasing
   *          True to create an increasing only or false to create a decreasing
   *          only.
   * @return A directional counter.
   */
  public static LongCounter makeDirectional(final LongCounter counter, final boolean increasing) {
    LongCounter temp;
    if (increasing) {
      temp = new Wrapper(counter) {
        /** The serialVersionUID */
        private static final long serialVersionUID = -8902748795144754375L;

        public long decrement() {
          throw new UnsupportedOperationException();
        }

        public void reset() {
          throw new UnsupportedOperationException();
        }
      };
    } else {
      temp = new Wrapper(counter) {
        /** The serialVersionUID */
        private static final long serialVersionUID = 2584758778978644599L;

        public long increment() {
          throw new UnsupportedOperationException();
        }
      };
    }

    return temp;
  }
}

   
    
    
    
    
  

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