1 /*
2 * Copyright (c) 2011. The Apache Software Foundation
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 package org.apache.expreval.expr.literal;
22
23 import org.apache.expreval.expr.node.GenericValue;
24 import org.apache.expreval.expr.node.ObjectValue;
25
26 import java.io.Serializable;
27
28 public class NullLiteral extends GenericLiteral<Serializable> implements ObjectValue {
29
30 public NullLiteral() {
31 super(null);
32 }
33
34 protected Class<? extends GenericValue> getReturnType() {
35 return ObjectValue.class;
36 }
37
38 public String asString() {
39 return "NULL";
40 }
41 }