001    /* 
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *   http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.felix.framework.cache;
020    
021    import org.apache.felix.moduleloader.*;
022    import java.io.IOException;
023    import java.io.InputStream;
024    import java.util.Enumeration;
025    import java.util.NoSuchElementException;
026    
027    public class ContentDirectoryContent implements IContent
028    {
029        private IContent m_content = null;
030        private String m_rootPath = null;
031    
032        public ContentDirectoryContent(IContent content, String path)
033        {
034            m_content = content;
035            // Add a '/' to the end if not present.
036            m_rootPath = (path.length() > 0) && (path.charAt(path.length() - 1) != '/')
037                ? path + "/" : path;
038        }
039    
040        public synchronized void close()
041        {
042            // We do not actually close the associated content
043            // from which we are filtering our directory because
044            // we assume that this will be close manually by
045            // the owner of that content.
046            m_content = null;
047        }
048    
049        public synchronized boolean hasEntry(String name) throws IllegalStateException
050        {
051            if ((name.length() > 0) && (name.charAt(0) == '/'))
052            {
053                name = name.substring(1);
054            }
055    
056            return m_content.hasEntry(m_rootPath + name);
057        }
058    
059        public synchronized Enumeration getEntries()
060        {
061            return new EntriesEnumeration(m_content.getEntries(), m_rootPath);
062        }
063    
064        public synchronized byte[] getEntryAsBytes(String name) throws IllegalStateException
065        {
066            if ((name.length() > 0) && (name.charAt(0) == '/'))
067            {
068                name = name.substring(1);
069            }
070    
071            return m_content.getEntryAsBytes(m_rootPath + name);
072        }
073    
074        public synchronized InputStream getEntryAsStream(String name)
075            throws IllegalStateException, IOException
076        {
077            if ((name.length() > 0) && (name.charAt(0) == '/'))
078            {
079                name = name.substring(1);
080            }
081    
082            return m_content.getEntryAsStream(m_rootPath + name);
083        }
084    
085        public IContent getEntryAsContent(String name)
086        {
087            if ((name.length() > 0) && (name.charAt(0) == '/'))
088            {
089                name = name.substring(1);
090            }
091    
092            return m_content.getEntryAsContent(m_rootPath + name);
093        }
094    
095        public String getEntryAsNativeLibrary(String name)
096        {
097            if ((name.length() > 0) && (name.charAt(0) == '/'))
098            {
099                name = name.substring(1);
100            }
101    
102            return m_content.getEntryAsNativeLibrary(m_rootPath + name);
103        }
104    
105        public String toString()
106        {
107            return "CONTENT DIR " + m_rootPath + " (" + m_content + ")";
108        }
109    
110        private static class EntriesEnumeration implements Enumeration
111        {
112            private Enumeration m_enumeration = null;
113            private String m_rootPath = null;
114            private String m_nextEntry = null;
115    
116            public EntriesEnumeration(Enumeration enumeration, String rootPath)
117            {
118                m_enumeration = enumeration;
119                m_rootPath = rootPath;
120                m_nextEntry = findNextEntry();
121            }
122    
123            public boolean hasMoreElements()
124            {
125                return (m_nextEntry != null);
126            }
127    
128            public Object nextElement()
129            {
130                if (m_nextEntry == null)
131                {
132                    throw new NoSuchElementException("No more elements.");
133                }
134                String currentEntry = m_nextEntry;
135                m_nextEntry = findNextEntry();
136                return currentEntry;
137            }
138    
139            private String findNextEntry()
140            {
141                // Find next entry that is inside the root directory.
142                while (m_enumeration.hasMoreElements())
143                {
144                    String next = (String) m_enumeration.nextElement();
145                    if (next.startsWith(m_rootPath) && !next.equals(m_rootPath))
146                    {
147                        // Strip off the root directory.
148                        return next.substring(m_rootPath.length());
149                    }
150                }
151                return null;
152            }
153        }
154    }