1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.el;
18
19 /**
20 *
21 * <p>An expression representing a null literal value
22 *
23 * @author Nathan Abramson - Art Technology Group
24 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: bayard $
25 **/
26
27 public class NullLiteral
28 extends Literal
29 {
30 //-------------------------------------
31 // Member variables
32 //-------------------------------------
33
34 public static final NullLiteral SINGLETON = new NullLiteral ();
35
36 //-------------------------------------
37 /**
38 *
39 * Constructor
40 **/
41 public NullLiteral ()
42 {
43 super (null);
44 }
45
46 //-------------------------------------
47 // Expression methods
48 //-------------------------------------
49 /**
50 *
51 * Returns the expression in the expression language syntax
52 **/
53 public String getExpressionString ()
54 {
55 return "null";
56 }
57
58 //-------------------------------------
59 }