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17
18 package javax.el;
19
20 import java.beans.FeatureDescriptor  ;
21 import java.util.ArrayList ;
22 import java.util.Arrays ;
23 import java.util.Collections ;
24 import java.util.Iterator ;
25 import java.util.List ;
26
27 public class ListELResolver extends ELResolver {
28
29 private final boolean readOnly;
30
31 private final static Class UNMODIFIABLE = Collections.unmodifiableList(
32 new ArrayList ()).getClass();
33
34 public ListELResolver() {
35 this.readOnly = false;
36 }
37
38 public ListELResolver(boolean readOnly) {
39 this.readOnly = readOnly;
40 }
41
42 public Object getValue(ELContext context, Object base, Object property)
43 throws NullPointerException , PropertyNotFoundException, ELException {
44 if (context == null) {
45 throw new NullPointerException ();
46 }
47
48 if (base instanceof List ) {
49 context.setPropertyResolved(true);
50 List list = (List ) base;
51 int idx = coerce(property);
52 if (idx < 0 || idx >= list.size()) {
53 return null;
54 }
55 return list.get(idx);
56 }
57
58 return null;
59 }
60
61 public Class <?> getType(ELContext context, Object base, Object property)
62 throws NullPointerException , PropertyNotFoundException, ELException {
63 if (context == null) {
64 throw new NullPointerException ();
65 }
66
67 if (base instanceof List ) {
68 context.setPropertyResolved(true);
69 List list = (List ) base;
70 int idx = coerce(property);
71 if (idx < 0 || idx >= list.size()) {
72 return null;
73 }
74 Object obj = list.get(idx);
75 return (obj != null) ? obj.getClass() : null;
76 }
77
78 return null;
79 }
80
81 public void setValue(ELContext context, Object base, Object property,
82 Object value) throws NullPointerException ,
83 PropertyNotFoundException, PropertyNotWritableException,
84 ELException {
85 if (context == null) {
86 throw new NullPointerException ();
87 }
88
89 if (base instanceof List ) {
90 context.setPropertyResolved(true);
91 List list = (List ) base;
92
93 if (this.readOnly) {
94 throw new PropertyNotWritableException(message(context,
95 "resolverNotWriteable", new Object [] { base.getClass()
96 .getName() }));
97 }
98
99 int idx = coerce(property);
100 try {
101 list.set(idx, value);
102 } catch (UnsupportedOperationException e) {
103 throw new PropertyNotWritableException(e);
104 } catch (IndexOutOfBoundsException e) {
105 throw new PropertyNotFoundException(e);
106 }
107 }
108 }
109
110 public boolean isReadOnly(ELContext context, Object base, Object property)
111 throws NullPointerException , PropertyNotFoundException, ELException {
112 if (context == null) {
113 throw new NullPointerException ();
114 }
115
116 if (base instanceof List ) {
117 context.setPropertyResolved(true);
118 List list = (List ) base;
119 int idx = coerce(property);
120 if (idx < 0 || idx >= list.size()) {
121 throw new PropertyNotFoundException(
122 new ArrayIndexOutOfBoundsException (idx).getMessage());
123 }
124 return this.readOnly || UNMODIFIABLE.equals(list.getClass());
125 }
126
127 return this.readOnly;
128 }
129
130 public Iterator <FeatureDescriptor > getFeatureDescriptors(ELContext context, Object base) {
131 if (base instanceof List ) {
132 FeatureDescriptor [] descs = new FeatureDescriptor [((List ) base).size()];
133 for (int i = 0; i < descs.length; i++) {
134 descs[i] = new FeatureDescriptor ();
135 descs[i].setDisplayName("["+i+"]");
136 descs[i].setExpert(false);
137 descs[i].setHidden(false);
138 descs[i].setName(""+i);
139 descs[i].setPreferred(true);
140 descs[i].setValue(RESOLVABLE_AT_DESIGN_TIME, Boolean.FALSE);
141 descs[i].setValue(TYPE, Integer .class);
142 }
143 return Arrays.asList(descs).iterator();
144 }
145 return null;
146 }
147
148 public Class <?> getCommonPropertyType(ELContext context, Object base) {
149 if (base != null && base instanceof List ) {
150 return Integer .class;
151 }
152 return null;
153 }
154
155 private final static int coerce(Object property) {
156 if (property instanceof Number ) {
157 return ((Number ) property).intValue();
158 }
159 if (property instanceof Character ) {
160 return ((Character ) property).charValue();
161 }
162 if (property instanceof Boolean ) {
163 return (((Boolean ) property).booleanValue() ? 1 : 0);
164 }
165 if (property instanceof String ) {
166 return Integer.parseInt((String ) property);
167 }
168 throw new IllegalArgumentException (property != null ? property
169 .toString() : "null");
170 }
171 }
172 |
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