esnull.java

来自「RESIN 3.2 最新源码」· Java 代码 · 共 78 行

/*
 * Copyright (c) 1998-2006 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 SoftwareFoundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.es;

public class ESNull extends ESBase {
  ESNull()
  {
    prototype = ESBase.esBase;
    className = "null";
  }

  public ESBase typeof() throws ESException
  {
    return ESString.create("object");
  }

  public Class getJavaType()
  {
    return Object.class;
  }

  public ESBase getProperty(ESString key) throws ESException
  {
    throw new ESNullException(className + " has no properties");
  }

  public void setProperty(ESString key, ESBase value) throws ESException
  {
    throw new ESNullException(className + " has no properties");
  }

  public double toNum() throws ESException
  {
    return 0;
  }

  public ESString toStr() throws ESException
  {
    return ESString.create("null");
  }

  public String toJavaString() throws ESException
  {
    return null;
  }

  public boolean ecmaEquals(ESBase b)
  {
    return this == b || b == esUndefined;
  }
}