lessthanoperator.java

来自「jakarta-taglibs」· Java 代码 · 共 119 行

/*
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed 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.taglibs.standard.lang.jstl;

/**
 *
 * <p>The implementation of the less than operator
 * 
 * @author Nathan Abramson - Art Technology Group
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: pierred $
 **/

public class LessThanOperator
  extends RelationalOperator
{
  //-------------------------------------
  // Singleton
  //-------------------------------------

  public static final LessThanOperator SINGLETON =
    new LessThanOperator ();

  //-------------------------------------
  /**
   *
   * Constructor
   **/
  public LessThanOperator ()
  {
  }

  //-------------------------------------
  // Expression methods
  //-------------------------------------
  /**
   *
   * Returns the symbol representing the operator
   **/
  public String getOperatorSymbol ()
  {
    return "<";
  }

  //-------------------------------------
  /**
   *
   * Applies the operator to the given value
   **/
  public Object apply (Object pLeft,
		       Object pRight,
		       Object pContext,
		       Logger pLogger)
    throws ELException
  {
    if (pLeft == pRight) {
      return Boolean.FALSE;
    }
    else if (pLeft == null ||
	     pRight == null) {
      return Boolean.FALSE;
    }
    else {
      return super.apply (pLeft, pRight, pContext, pLogger);
    }
  }

  //-------------------------------------
  /**
   *
   * Applies the operator to the given double values
   **/
  public boolean apply (double pLeft,
			double pRight,
			Logger pLogger)
  {
    return pLeft < pRight;
  }
  
  //-------------------------------------
  /**
   *
   * Applies the operator to the given long values
   **/
  public boolean apply (long pLeft,
			long pRight,
			Logger pLogger)
  {
    return pLeft < pRight;
  }
  
  //-------------------------------------
  /**
   *
   * Applies the operator to the given String values
   **/
  public boolean apply (String pLeft,
			String pRight,
			Logger pLogger)
  {
    return pLeft.compareTo (pRight) < 0;
  }

  //-------------------------------------
}