BeanDoubleComparator.java

/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/sam/trunk/samigo-app/src/java/org/sakaiproject/tool/assessment/util/BeanDoubleComparator.java $
 * $Id: BeanDoubleComparator.java 121258 2013-03-15 15:03:36Z ottenhoff@longsight.com $
 ***********************************************************************************
 *
 * Copyright (c) 2005, 2006, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.tool.assessment.util;

import java.util.Map;

/**
 * DOCUMENTATION PENDING
 *
 * @author $author$
 * @version $Id: BeanDoubleComparator.java 121258 2013-03-15 15:03:36Z ottenhoff@longsight.com $
 */
public class BeanDoubleComparator
  extends BeanSortComparator
{
  private String propertyName;

  /**
   * The only public constructor.  Requires a valid property name for a a Java
   * Bean as a sole parameter.
   *
   * @param propertyName the property name for Java Bean to sort by
   */
  public BeanDoubleComparator(String propertyName)
  {
    this.propertyName = propertyName;
  }

  /**
   * Creates a new BeanDoubleComparator object.
   */
  protected BeanDoubleComparator()
  {
  }
  ;

  /**
   * standard compare method
   *
   * @param o1 object
   * @param o2 object
   *
   * @return lt, eq, gt zero depending on whether o1 numerically lt,eq,gt o2
   *
   * @throws java.lang.UnsupportedOperationException DOCUMENTATION PENDING
   */
  public int compare(Object o1, Object o2)
  {
    Map m1 = describeBean(o1);
    Map m2 = describeBean(o2);
    String s1 = (String) m1.get(propertyName);
    String s2 = (String) m2.get(propertyName);
    Double i1 = null;
    Double i2 = null;
    boolean firstDoubleValid = true;
    boolean secondDoubleValid = true;

    try
    {
    	i1 = new Double(s1);
    }
    catch (NumberFormatException e)
    {
    	firstDoubleValid = false;
    }

    try
    {
    	i2 = new Double(s2);
    }
    catch (NumberFormatException e)
    {
    	secondDoubleValid = false;
    }

    int returnValue=0;
    if (firstDoubleValid && secondDoubleValid) {
    	if (i1 != null) {
    		returnValue = i1.compareTo(i2);
    	}
    }
    if (firstDoubleValid && !secondDoubleValid) returnValue = 1;
    if (!firstDoubleValid && secondDoubleValid) returnValue = -1;
    if (!firstDoubleValid && !secondDoubleValid) returnValue = 0;

    return returnValue;
  }
}