Source code: ognl/ListPropertyAccessor.java
1 //--------------------------------------------------------------------------
2 // Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
3 // All rights reserved.
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 // Redistributions of source code must retain the above copyright notice,
10 // this list of conditions and the following disclaimer.
11 // Redistributions in binary form must reproduce the above copyright
12 // notice, this list of conditions and the following disclaimer in the
13 // documentation and/or other materials provided with the distribution.
14 // Neither the name of the Drew Davidson nor the names of its contributors
15 // may be used to endorse or promote products derived from this software
16 // without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25 // OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 // AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
28 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
29 // DAMAGE.
30 //--------------------------------------------------------------------------
31 package ognl;
32
33 import java.util.*;
34
35 /**
36 * Implementation of PropertyAccessor that uses numbers and dynamic subscripts as
37 * properties to index into Lists.
38 * @author Luke Blanshard (blanshlu@netscape.net)
39 * @author Drew Davidson (drew@ognl.org)
40 */
41 public class ListPropertyAccessor extends ObjectPropertyAccessor
42 implements PropertyAccessor // This is here to make javadoc show this class as an implementor
43 {
44 public Object getProperty( Map context, Object target, Object name ) throws OgnlException
45 {
46 List list = (List)target;
47
48 if ( name instanceof String ) {
49 Object result;
50
51 if (name.equals("size")) {
52 result = new Integer(list.size());
53 } else {
54 if (name.equals("iterator")) {
55 result = list.iterator();
56 } else {
57 if (name.equals("isEmpty")) {
58 result = list.isEmpty() ? Boolean.TRUE : Boolean.FALSE;
59 } else {
60 result = super.getProperty( context, target, name );
61 }
62 }
63 }
64 return result;
65 }
66
67 if ( name instanceof Number )
68 return list.get( ((Number)name).intValue() );
69
70 if ( name instanceof DynamicSubscript )
71 {
72 int len = list.size();
73 switch ( ((DynamicSubscript)name).getFlag() )
74 {
75 case DynamicSubscript.FIRST: return len > 0? list.get(0) : null;
76 case DynamicSubscript.MID: return len > 0? list.get(len/2) : null;
77 case DynamicSubscript.LAST: return len > 0? list.get(len-1) : null;
78 case DynamicSubscript.ALL: return new ArrayList(list);
79 }
80 }
81
82 throw new NoSuchPropertyException( target, name );
83 }
84
85 public void setProperty( Map context, Object target, Object name, Object value ) throws OgnlException
86 {
87 if ( name instanceof String )
88 {
89 super.setProperty( context, target, name, value );
90 return;
91 }
92
93 List list = (List)target;
94
95 if ( name instanceof Number )
96 {
97 list.set( ((Number)name).intValue(), value );
98 return;
99 }
100
101 if ( name instanceof DynamicSubscript )
102 {
103 int len = list.size();
104 switch ( ((DynamicSubscript)name).getFlag() )
105 {
106 case DynamicSubscript.FIRST: if ( len > 0 ) list.set(0,value); return;
107 case DynamicSubscript.MID: if ( len > 0 ) list.set(len/2,value); return;
108 case DynamicSubscript.LAST: if ( len > 0 ) list.set(len-1,value); return;
109 case DynamicSubscript.ALL:
110 {
111 if ( !(value instanceof Collection) )
112 throw new OgnlException( "Value must be a collection" );
113 list.clear();
114 list.addAll( (Collection)value );
115 return;
116 }
117 }
118 }
119
120 throw new NoSuchPropertyException( target, name );
121 }
122 }