View Javadoc

1   /*
2    * Copyright (c) 2003, Henri Yandell
3    * All rights reserved.
4    * 
5    * Redistribution and use in source and binary forms, with or 
6    * without modification, are permitted provided that the 
7    * following conditions are met:
8    * 
9    * + Redistributions of source code must retain the above copyright notice, 
10   *   this list of conditions and the following disclaimer.
11   * 
12   * + Redistributions in binary form must reproduce the above copyright notice, 
13   *   this list of conditions and the following disclaimer in the documentation 
14   *   and/or other materials provided with the distribution.
15   * 
16   * + Neither the name of Genjava-Core nor the names of its contributors 
17   *   may be used to endorse or promote products derived from this software 
18   *   without specific prior written permission.
19   * 
20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
23   * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
30   * POSSIBILITY OF SUCH DAMAGE.
31   */
32  // OrderedSet.java
33  //package com.generationjava.collections;
34  package org.osjava.sj.loader.util;
35  
36  import java.util.Set;
37  import java.util.Collection;
38  import java.util.Iterator;
39  import java.util.List;
40  import java.util.LinkedList;
41  
42  /***
43   * An implementation of Set that guarentees ordering 
44   * remains constant.
45   */
46  class OrderedSet implements Set {
47  
48      private List list = null;
49  
50      public OrderedSet() {
51          this.list = new LinkedList();
52      }
53  
54      public OrderedSet(Collection c) {
55          this();
56          if(c != null) {
57              Iterator iterator = c.iterator();
58              while(iterator.hasNext()) {
59                  add(iterator.next());
60              }
61          }
62      }
63      
64      /***
65       * Create using the given List as the internal storage method.
66       */
67      public OrderedSet(List list) {
68          this.list = list;
69      }
70      
71      public boolean add(Object obj) {
72       // Adds the specified element to this set if it is not already present (optional operation).         
73           if(!contains(obj)) {
74               list.add(obj);
75               return true;
76           }
77          return false;
78      }
79  
80      public boolean addAll(Collection c) {
81       // Adds all of the elements in the specified collection to this set if they're not already present (optional operation).         
82          boolean ret = false;
83          if(c != null) {
84              Iterator iterator = c.iterator();
85              while(iterator.hasNext()) {
86                  if(add(iterator.next())) {
87                      ret = true;
88                  }
89              }
90          }
91          return ret;
92      }
93  
94      public void clear() {
95       // Removes all of the elements from this set (optional operation).         
96           list.clear();
97      }
98  
99      public boolean contains(Object obj) {
100      // Returns true if this set contains the specified element.         
101          return list.contains(obj);
102     }
103 
104     public boolean containsAll(Collection c) {
105      // Returns true if this set contains all of the elements of the specified collection.         
106          return list.containsAll(c);
107     }
108 
109     public boolean equals(Object obj) {
110      // Compares the specified object with this set for equality.
111          return list.equals(obj);
112     }
113 
114     public int hashCode() {
115      // Returns the hash code value for this set.         
116          return list.hashCode();
117     }
118 
119     public boolean isEmpty() {
120      // Returns true if this set contains no elements.         
121          return list.isEmpty();
122     }
123 
124     public Iterator iterator() {
125      // Returns an iterator over the elements in this set.         
126          return list.iterator();
127     }
128 
129     public boolean remove(Object obj) {
130      // Removes the specified element from this set if it is present (optional operation).         
131          return list.remove(obj);
132     }
133 
134     public boolean removeAll(Collection c) {
135      // Removes from this set all of its elements that are contained in the specified collection (optional operation).         
136          return list.removeAll(c);
137     }
138 
139     public boolean retainAll(Collection c) {
140      // Retains only the elements in this set that are contained in the specified collection (optional operation).         
141         boolean ret = false;
142         if(c != null) {
143             Iterator iterator = c.iterator();
144             while(iterator.hasNext()) {
145                 Object obj = iterator.next();
146                 if(!contains(obj)) {
147                     remove(obj);
148                     ret = true;
149                 }
150             }
151         }
152         return ret;
153     }
154 
155     public int size() {
156      // Returns the number of elements in this set (its cardinality).         
157          return list.size();
158     }
159 
160     public Object[] toArray() {              
161      // Returns an array containing all of the elements in this set.         
162          return list.toArray();
163     }
164 
165     public Object[] toArray(Object[] arr) {              
166      // Returns an array containing all of the elements in this set whose runtime type is that of the specified array.
167          return list.toArray(arr);
168     }
169 
170 }