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002 * Licensed to the Apache Software Foundation (ASF) under one   *
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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 *                                                              *
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013 * software distributed under the License is distributed on an  *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
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019
020package org.apache.james.mime4j.storage;
021
022import java.io.IOException;
023import java.io.InputStream;
024
025/**
026 * Can be used to read data that has been stored by a {@link StorageProvider}.
027 */
028public interface Storage {
029    /**
030     * Returns an <code>InputStream</code> that can be used to read the stored
031     * data. The input stream should be closed by the caller when it is no
032     * longer needed.
033     * <p>
034     * Note: The stream should NOT be wrapped in a
035     * <code>BufferedInputStream</code> by the caller. If the implementing
036     * <code>Storage</code> creates a stream which would benefit from being
037     * buffered it is the <code>Storage</code>'s responsibility to wrap it.
038     *
039     * @return an <code>InputStream</code> for reading the stored data.
040     * @throws IOException
041     *             if an I/O error occurs.
042     * @throws IllegalStateException
043     *             if this <code>Storage</code> instance has been deleted.
044     */
045    InputStream getInputStream() throws IOException;
046
047    /**
048     * Deletes the data held by this <code>Storage</code> as soon as possible.
049     * Deleting an already deleted <code>Storage</code> has no effect.
050     */
051    void delete();
052
053}