com.caucho.servlets.ssi.SSIExpr Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 1998-2018 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source 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, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.servlets.ssi;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Represents a SSI expression
 */
abstract public class SSIExpr {
  /**
   * Evaluate as a string.
   */
  abstract public String evalString(HttpServletRequest request,
                                    HttpServletResponse response);
  /**
   * Evaluate as a boolean.
   */
  public boolean evalBoolean(HttpServletRequest request,
                             HttpServletResponse response)
  {
    String value = evalString(request, response);

    if (value == null
        || "".equals(value)
        || "null".equals(value)
        || "false".equals(value)
        || "0".equals(value)) {
      return false;
    }
    else
      return true;
  }
}