001 package org.apache.commons.ognl; 002 003 /* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022 /** 023 * This class has predefined instances that stand for OGNL's special "dynamic subscripts" for getting at the first, 024 * middle, or last elements of a list. In OGNL expressions, these subscripts look like special kinds of array indexes: 025 * [^] means the first element, [$] means the last, [|] means the middle, and [*] means the whole list. 026 * 027 * @author Luke Blanshard (blanshlu@netscape.net) 028 * @author Drew Davidson (drew@ognl.org) 029 */ 030 public class DynamicSubscript 031 { 032 public static final int FIRST = 0; 033 034 public static final int MID = 1; 035 036 public static final int LAST = 2; 037 038 public static final int ALL = 3; 039 040 public static final DynamicSubscript first = new DynamicSubscript( FIRST ); 041 042 public static final DynamicSubscript mid = new DynamicSubscript( MID ); 043 044 public static final DynamicSubscript last = new DynamicSubscript( LAST ); 045 046 public static final DynamicSubscript all = new DynamicSubscript( ALL ); 047 048 private int flag; 049 050 private DynamicSubscript( int flag ) 051 { 052 this.flag = flag; 053 } 054 055 public int getFlag() 056 { 057 return flag; 058 } 059 060 @Override 061 public String toString() 062 { 063 switch ( flag ) 064 { 065 case FIRST: 066 return "^"; 067 case MID: 068 return "|"; 069 case LAST: 070 return "$"; 071 case ALL: 072 return "*"; 073 default: 074 return "?"; // Won't happen 075 } 076 } 077 }