| /* |
| * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//jxpath/src/java/org/apache/commons/jxpath/BasicVariables.java,v 1.3 2002/05/08 23:02:42 dmitri Exp $ |
| * $Revision: 1.3 $ |
| * $Date: 2002/05/08 23:02:42 $ |
| * |
| * ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 1999-2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Commons", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Group. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 2001, Plotnix, Inc, |
| * <http://www.plotnix.com/>. |
| * For more information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.commons.jxpath; |
| |
| import java.util.HashMap; |
| |
| /** |
| * A basic implementation of the Variables interface that uses a HashMap. |
| * |
| * @author Dmitri Plotnikov |
| * @version $Revision: 1.3 $ $Date: 2002/05/08 23:02:42 $ |
| */ |
| public class BasicVariables implements Variables { |
| |
| /** |
| * Contains the values of declared variables |
| */ |
| private HashMap vars = new HashMap(); |
| |
| /** |
| * Returns true if the variable has been defined, even if the |
| * value of the variable is null. |
| * |
| * @param varName is a variable name without the "$" sign |
| * |
| * @return true if the variable is declared |
| */ |
| public boolean isDeclaredVariable(String varName){ |
| return vars.containsKey(varName); |
| } |
| |
| /** |
| * Returns the value of the variable if it is defined, |
| * otherwise, throws IllegalArgumentException |
| * |
| * @param varName is a variable name without the "$" sign |
| * |
| * @return the value of the variable |
| */ |
| public Object getVariable(String varName){ |
| // Note that a variable may be defined with a null value |
| |
| if (vars.containsKey(varName)){ |
| return vars.get(varName); |
| } |
| |
| throw new IllegalArgumentException("No such variable: '" + varName + "'"); |
| } |
| |
| /** |
| * Defines a new variable with the specified value or modifies |
| * the value of an existing variable. |
| * |
| * @param varName is a variable name without the "$" sign |
| * @param value is the new value for the variable, which can be null |
| */ |
| public void declareVariable(String varName, Object value){ |
| vars.put(varName, value); |
| } |
| |
| /** |
| * Removes an existing variable. May throw UnsupportedOperationException. |
| * |
| * @param varName is a variable name without the "$" sign |
| */ |
| public void undeclareVariable(String varName){ |
| vars.remove(varName); |
| } |
| public String toString(){ |
| return vars.toString(); |
| } |
| } |