1 package org.apache.commons.ognl;
2
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,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 /**
23 * This class has predefined instances that stand for OGNL's special "dynamic subscripts" for getting at the first,
24 * middle, or last elements of a list. In OGNL expressions, these subscripts look like special kinds of array indexes:
25 * [^] means the first element, [$] means the last, [|] means the middle, and [*] means the whole list.
26 *
27 * @author Luke Blanshard (blanshlu@netscape.net)
28 * @author Drew Davidson (drew@ognl.org)
29 */
30 public class DynamicSubscript
31 {
32 public static final int FIRST = 0;
33
34 public static final int MID = 1;
35
36 public static final int LAST = 2;
37
38 public static final int ALL = 3;
39
40 public static final DynamicSubscript first = new DynamicSubscript( FIRST );
41
42 public static final DynamicSubscript mid = new DynamicSubscript( MID );
43
44 public static final DynamicSubscript last = new DynamicSubscript( LAST );
45
46 public static final DynamicSubscript all = new DynamicSubscript( ALL );
47
48 private int flag;
49
50 private DynamicSubscript( int flag )
51 {
52 this.flag = flag;
53 }
54
55 public int getFlag()
56 {
57 return flag;
58 }
59
60 @Override
61 public String toString()
62 {
63 switch ( flag )
64 {
65 case FIRST:
66 return "^";
67 case MID:
68 return "|";
69 case LAST:
70 return "$";
71 case ALL:
72 return "*";
73 default:
74 return "?"; // Won't happen
75 }
76 }
77 }