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1   /*
2    * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  /**
27    * Given an enumeration of candidates, check whether each
28    * item in enumeration satifies the given filter.
29    * Each item is a Binding and the following is used to get its
30    * attributes for used by the filter:
31    *
32    *   ((DirContext)item.getObject()).getAttributes("").
33    * If item.getObject() is not an DirContext, the item is skipped
34    *
35    * The items in the enumeration are obtained one at a time as
36    * items from the search enumeration are requested.
37    *
38    * @author Rosanna Lee
39    */
40  
41  package com.sun.jndi.toolkit.dir;
42  
43  import javax.naming.*;
44  import javax.naming.directory.*;
45  import javax.naming.spi.DirectoryManager;
46  
47  import java.util.NoSuchElementException;
48  import java.util.Hashtable;
49  
50  final public class LazySearchEnumerationImpl
51          implements NamingEnumeration<SearchResult> {
52      private NamingEnumeration<Binding> candidates;
53      private SearchResult nextMatch = null;
54      private SearchControls cons;
55      private AttrFilter filter;
56      private Context context;
57      private Hashtable<String, Object> env;
58      private boolean useFactory = true;
59  
60      public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates,
61          AttrFilter filter, SearchControls cons) throws NamingException {
62              this.candidates = candidates;
63              this.filter = filter;
64  
65              if(cons == null) {
66                  this.cons = new SearchControls();
67              } else {
68                  this.cons = cons;
69              }
70      }
71  
72      @SuppressWarnings("unchecked")      // For Hashtable clone: env.clone()
73      public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates,
74          AttrFilter filter, SearchControls cons,
75          Context ctx, Hashtable<String, Object> env, boolean useFactory)
76          throws NamingException {
77  
78              this.candidates = candidates;
79              this.filter = filter;
80              this.env = (Hashtable<String, Object>)
81                      ((env == null) ? null : env.clone());
82              this.context = ctx;
83              this.useFactory = useFactory;
84  
85              if(cons == null) {
86                  this.cons = new SearchControls();
87              } else {
88                  this.cons = cons;
89              }
90      }
91  
92  
93      public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates,
94          AttrFilter filter, SearchControls cons,
95          Context ctx, Hashtable<String, Object> env) throws NamingException {
96              this(candidates, filter, cons, ctx, env, true);
97      }
98  
99      public boolean hasMore() throws NamingException {
100         // find and do not remove from list
101         return findNextMatch(false) != null;
102     }
103 
104     public boolean hasMoreElements() {
105         try {
106             return hasMore();
107         } catch (NamingException e) {
108             return false;
109         }
110     }
111 
112     public SearchResult nextElement() {
113         try {
114             return findNextMatch(true);
115         } catch (NamingException e) {
116             throw new NoSuchElementException(e.toString());
117         }
118     }
119 
120     public SearchResult next() throws NamingException {
121         // find and remove from list
122         return (findNextMatch(true));
123     }
124 
125     public void close() throws NamingException {
126         if (candidates != null) {
127             candidates.close();
128         }
129     }
130 
131     private SearchResult findNextMatch(boolean remove) throws NamingException {
132         SearchResult answer;
133         if (nextMatch != null) {
134             answer = nextMatch;
135             if (remove) {
136                 nextMatch = null;
137             }
138             return answer;
139         } else {
140             // need to find next match
141             Binding next;
142             Object obj;
143             Attributes targetAttrs;
144             while (candidates.hasMore()) {
145                 next = candidates.next();
146                 obj = next.getObject();
147                 if (obj instanceof DirContext) {
148                     targetAttrs = ((DirContext)(obj)).getAttributes("");
149                     if (filter.check(targetAttrs)) {
150                         if (!cons.getReturningObjFlag()) {
151                             obj = null;
152                         } else if (useFactory) {
153                             try {
154                                 // Give name only if context non-null,
155                                 // otherewise, name will be interpreted relative
156                                 // to initial context (not what we want)
157                                 Name nm = (context != null ?
158                                     new CompositeName(next.getName()) : null);
159                                 obj = DirectoryManager.getObjectInstance(obj,
160                                     nm, context, env, targetAttrs);
161                             } catch (NamingException e) {
162                                 throw e;
163                             } catch (Exception e) {
164                                 NamingException e2 = new NamingException(
165                                     "problem generating object using object factory");
166                                 e2.setRootCause(e);
167                                 throw e2;
168                             }
169                         }
170                         answer = new SearchResult(next.getName(),
171                             next.getClassName(), obj,
172                             SearchFilter.selectAttributes(targetAttrs,
173                                 cons.getReturningAttributes()),
174                             true);
175                         if (!remove)
176                             nextMatch = answer;
177                         return answer;
178                     }
179                 }
180             }
181             return null;
182         }
183     }
184 }