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1
22 package org.jboss.util.collection;
23
24 import java.util.ArrayList  ;
25 import java.util.Collection ;
26 import java.util.Collections ;
27 import java.util.Iterator ;
28 import java.util.List ;
29 import java.util.ListIterator ;
30
31
37 public class LazyList implements List
38 {
39
40 private List delegate = Collections.EMPTY_LIST;
41
42 public void add(int index, Object element)
43 {
44 if (delegate instanceof ArrayList == false)
45 delegate = new ArrayList (delegate);
46 delegate.add(index, element);
47 }
48
49 public boolean add(Object o)
50 {
51 if (delegate == Collections.EMPTY_LIST)
52 {
53 delegate = Collections.singletonList(o);
54 return true;
55 }
56 else
57 {
58 if (delegate instanceof ArrayList == false)
59 delegate = new ArrayList (delegate);
60 return delegate.add(o);
61 }
62 }
63
64 public boolean addAll(Collection c)
65 {
66 if (delegate instanceof ArrayList == false)
67 delegate = new ArrayList (delegate);
68 return delegate.addAll(c);
69 }
70
71 public boolean addAll(int index, Collection c)
72 {
73 if (delegate instanceof ArrayList == false)
74 delegate = new ArrayList (delegate);
75 return delegate.addAll(index, c);
76 }
77
78 public void clear()
79 {
80 delegate = Collections.EMPTY_LIST;
81 }
82
83 public boolean contains(Object o)
84 {
85 return delegate.contains(o);
86 }
87
88 public boolean containsAll(Collection c)
89 {
90 return delegate.containsAll(c);
91 }
92
93 public Object get(int index)
94 {
95 return delegate.get(index);
96 }
97
98 public int indexOf(Object o)
99 {
100 return delegate.indexOf(o);
101 }
102
103 public boolean isEmpty()
104 {
105 return delegate.isEmpty();
106 }
107
108 public Iterator iterator()
109 {
110 return delegate.iterator();
111 }
112
113 public int lastIndexOf(Object o)
114 {
115 return delegate.lastIndexOf(o);
116 }
117
118 public ListIterator listIterator()
119 {
120 return delegate.listIterator();
121 }
122
123 public ListIterator listIterator(int index)
124 {
125 return delegate.listIterator(index);
126 }
127
128 public Object remove(int index)
129 {
130 if (delegate instanceof ArrayList == false)
131 delegate = new ArrayList (delegate);
132 return delegate.remove(index);
133 }
134
135 public boolean remove(Object o)
136 {
137 if (delegate instanceof ArrayList == false)
138 delegate = new ArrayList (delegate);
139 return delegate.remove(o);
140 }
141
142 public boolean removeAll(Collection c)
143 {
144 if (delegate instanceof ArrayList == false)
145 delegate = new ArrayList (delegate);
146 return delegate.remove(c);
147 }
148
149 public boolean retainAll(Collection c)
150 {
151 if (delegate instanceof ArrayList == false)
152 delegate = new ArrayList (delegate);
153 return delegate.retainAll(c);
154 }
155
156 public Object set(int index, Object element)
157 {
158 if (delegate instanceof ArrayList == false)
159 delegate = new ArrayList (delegate);
160 return delegate.set(index, element);
161 }
162
163 public int size()
164 {
165 return delegate.size();
166 }
167
168 public List subList(int fromIndex, int toIndex)
169 {
170 return delegate.subList(fromIndex, toIndex);
171 }
172
173 public Object [] toArray()
174 {
175 return delegate.toArray();
176 }
177
178 public Object [] toArray(Object [] a)
179 {
180 return delegate.toArray(a);
181 }
182 }
183 |
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