framework/src/main/java/org/apache/felix/moduleloader/ContentDirectoryContent.java

/* 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.felix.moduleloader;

import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;

public class ContentDirectoryContent implements IContent
{
    private IContent m_content = null;
    private String m_rootPath = null;
    private boolean m_opened = false;

    public ContentDirectoryContent(IContent content, String path)
    {
        m_content = content;
        // Add a '/' to the end if not present.
        m_rootPath = (path.length() > 0) && (path.charAt(path.length() - 1) != '/')
            ? path + "/" : path;
    }

    protected void finalize()
    {
        if (m_content != null)
        {
            m_content.close();
        }
    }

    public void open()
    {
        m_content.open();
        m_opened = true;
    }

    public synchronized void close()
    {
        try
        {
            if (m_content != null)
            {
                m_content.close();
            }
        }
        catch (Exception ex)
        {
            System.err.println("JarContent: " + ex);
        }

        m_content = null;
        m_opened = false;
    }

    public synchronized boolean hasEntry(String name) throws IllegalStateException
    {
        if (!m_opened)
        {
            throw new IllegalStateException("ContentDirectoryContent is not open");
        }

        if ((name.length() > 0) && (name.charAt(0) == '/'))
        {
            name = name.substring(1);
        }

        return m_content.hasEntry(m_rootPath + name);
    }

    public synchronized byte[] getEntry(String name) throws IllegalStateException
    {
        if (!m_opened)
        {
            throw new IllegalStateException("ContentDirectoryContent is not open");
        }

        if ((name.length() > 0) && (name.charAt(0) == '/'))
        {
            name = name.substring(1);
        }

        return m_content.getEntry(m_rootPath + name);
    }

    public synchronized InputStream getEntryAsStream(String name)
        throws IllegalStateException, IOException
    {
        if (!m_opened)
        {
            throw new IllegalStateException("ContentDirectoryContent is not open");
        }

        if ((name.length() > 0) && (name.charAt(0) == '/'))
        {
            name = name.substring(1);
        }

        return m_content.getEntryAsStream(m_rootPath + name);
    }

    public synchronized Enumeration getEntries()
    {
        if (!m_opened)
        {
            throw new IllegalStateException("ContentDirectoryContent is not open");
        }

        return new EntriesEnumeration(m_content.getEntries(), m_rootPath);
    }

    public String toString()
    {
        return "CONTENT DIR " + m_rootPath + " (" + m_content + ")";
    }

    private static class EntriesEnumeration implements Enumeration
    {
        private Enumeration m_enumeration = null;
        private String m_rootPath = null;

        public EntriesEnumeration(Enumeration enumeration, String rootPath)
        {
            m_enumeration = enumeration;
            m_rootPath = rootPath;
        }

        public boolean hasMoreElements()
        {
            return m_enumeration.hasMoreElements();
        }

        public Object nextElement()
        {
            // We need to treat the specified path as the root of the
            // content, so we need to strip off the leading path from
            // each entry because it is automatically added back on
            // in the other calls above.
            return ((String) m_enumeration.nextElement()).substring(m_rootPath.length());
        }
    }
}