| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.commons.jxpath; |
| |
| import java.util.HashMap; |
| |
| /** |
| * A basic implementation of the Variables interface that uses a HashMap. |
| * |
| * @author Dmitri Plotnikov |
| * @version $Revision$ $Date$ |
| */ |
| public class BasicVariables implements Variables { |
| private static final long serialVersionUID = 2708263960832062725L; |
| |
| /** |
| * 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(); |
| } |
| } |