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Java > Open Source Codes > org > apache > jetspeed > om > registry > base > PortletIterator


1 /*
2  * Copyright 2000-2001,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.jetspeed.om.registry.base;
18
19 import java.util.Iterator JavaDoc;
20 import java.util.Vector JavaDoc;
21
22 import java.util.NoSuchElementException JavaDoc;
23 import java.lang.UnsupportedOperationException JavaDoc;
24 import java.lang.IllegalStateException JavaDoc;
25
26 import org.apache.jetspeed.services.Registry;
27
28
29 /**
30  * PortletIterator - seamless iterator over nested vectors of portlet collections
31  *
32  *
33  * @author <a HREF="mailto:taylor@apache.org">David Sean Taylor</a>
34  * @version $Id: PortletIterator.java,v 1.3 2004/02/23 03:08:26 jford Exp $
35  */
36 public class PortletIterator implements Iterator JavaDoc
37 {
38     protected BasePortletEntry entry;
39     protected String JavaDoc method;
40     protected Vector JavaDoc vector ;
41     protected int index = 0;
42
43     public PortletIterator(BasePortletEntry entry, String JavaDoc method)
44     {
45         this.entry = entry;
46         this.method = method;
47         this.vector = getVector();
48     }
49
50     public boolean hasNext()
51     {
52         int size = vector.size();
53
54         if (size == 0)
55             return false;
56
57         if (index >= size)
58         {
59             entry = getParentEntry(entry);
60             if (entry == null)
61                 return false;
62             vector = getVector();
63
64             if (vector == null)
65             {
66                 return false;
67             }
68             index = 0;
69             if (vector.size() == 0)
70                 return false;
71         }
72         return true;
73     }
74
75     public void remove() throws IllegalStateException JavaDoc, UnsupportedOperationException JavaDoc
76     {
77         throw new UnsupportedOperationException JavaDoc("The remove() method is not supported");
78     }
79
80     protected BasePortletEntry getParentEntry(BasePortletEntry entry)
81     {
82         String JavaDoc parentName = entry.getParent();
83         if (parentName == null || parentName.equals(""))
84             return null;
85
86         BasePortletEntry parent = null;
87         parent = (BasePortletEntry)Registry.getEntry( Registry.PORTLET, entry.getParent() );
88         return parent;
89     }
90
91     public Object JavaDoc next() throws NoSuchElementException JavaDoc
92     {
93         Object JavaDoc o = vector.elementAt(index);
94         index++;
95         return o;
96     }
97
98     protected Vector JavaDoc getVector()
99     {
100         try
101         {
102             this.vector = (Vector JavaDoc)this.entry.getClass().getMethod(this.method, null).invoke(this.entry, null);
103         }
104         catch (Exception JavaDoc e)
105         {
106             this.vector = null;
107         }
108
109         return this.vector;
110     }
111 }
112
113
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