| /* |
| * Copyright 2002,2004 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.commons.jelly.expression; |
| |
| import org.apache.commons.jelly.JellyContext; |
| |
| /** <p><code>ConstantExpression</code> represents a constant expression.</p> |
| * |
| * <p> In other words, {@link #evaluate} returns a value independent of the context. </p> |
| * |
| * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> |
| * @version $Revision: 1.9 $ |
| */ |
| public class ConstantExpression extends ExpressionSupport { |
| |
| /** The value of this expression */ |
| private Object value; |
| |
| /** Base constructor |
| */ |
| public ConstantExpression() { |
| } |
| |
| /** Convenience constructor sets <code>value</code> property. |
| */ |
| public ConstantExpression(Object value) { |
| this.value = value; |
| } |
| |
| public String toString() { |
| return super.toString() + "[value=" + value +"]"; |
| } |
| |
| public String getExpressionText() { |
| return value == null ? "null" : value.toString(); |
| } |
| |
| /** |
| * Evaluate expression against given context. |
| * |
| * @param context evaluate expression against this context |
| * @return current value of <code>value</code> property |
| */ |
| public Object evaluate(JellyContext context) { |
| return value; |
| } |
| |
| /** Gets the constant value of this expression */ |
| public Object getValue() { |
| return value; |
| } |
| |
| /** Sets the constant value of this expression */ |
| public void setValue(Object value) { |
| this.value = value; |
| } |
| } |