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 */
019package org.apache.commons.compress.archivers;
020
021import java.io.File;
022import java.io.IOException;
023import java.io.OutputStream;
024import java.nio.file.LinkOption;
025import java.nio.file.Path;
026
027/**
028 * Archive output stream implementations are expected to override the
029 * {@link #write(byte[], int, int)} method to improve performance.
030 * They should also override {@link #close()} to ensure that any necessary
031 * trailers are added.
032 *
033 * <p>The normal sequence of calls when working with ArchiveOutputStreams is:</p>
034 * <ul>
035 *   <li>Create ArchiveOutputStream object,</li>
036 *   <li>optionally write SFX header (Zip only),</li>
037 *   <li>repeat as needed:
038 *     <ul>
039 *       <li>{@link #putArchiveEntry(ArchiveEntry)} (writes entry header),
040 *       <li>{@link #write(byte[])} (writes entry data, as often as needed),
041 *       <li>{@link #closeArchiveEntry()} (closes entry),
042 *     </ul>
043 *   </li>
044 *   <li> {@link #finish()} (ends the addition of entries),</li>
045 *   <li> optionally write additional data, provided format supports it,</li>
046 *   <li>{@link #close()}.</li>
047 * </ul>
048 * @param <E> The type of {@link ArchiveEntry} consumed.
049 */
050public abstract class ArchiveOutputStream<E extends ArchiveEntry> extends OutputStream {
051
052    static final int BYTE_MASK = 0xFF;
053
054    /** Temporary buffer used for the {@link #write(int)} method. */
055    private final byte[] oneByte = new byte[1];
056
057    /** holds the number of bytes written to this stream. */
058    private long bytesWritten;
059
060    /**
061     * Whether this stream is able to write the given entry.
062     *
063     * <p>Some archive formats support variants or details that are
064     * not supported (yet).</p>
065     *
066     * @param archiveEntry
067     *            the entry to test
068     * @return This implementation always returns true.
069     * @since 1.1
070     */
071    public boolean canWriteEntryData(final ArchiveEntry archiveEntry) {
072        return true;
073    }
074
075    /**
076     * Closes the archive entry, writing any trailer information that may
077     * be required.
078     * @throws IOException if an I/O error occurs
079     */
080    public abstract void closeArchiveEntry() throws IOException;
081
082    /**
083     * Increments the counter of already written bytes.
084     * Doesn't increment if EOF has been hit ({@code written == -1}).
085     *
086     * @param written the number of bytes written
087     */
088    protected void count(final int written) {
089        count((long) written);
090    }
091
092    /**
093     * Increments the counter of already written bytes.
094     * Doesn't increment if EOF has been hit ({@code written == -1}).
095     *
096     * @param written the number of bytes written
097     * @since 1.1
098     */
099    protected void count(final long written) {
100        if (written != -1) {
101            bytesWritten = bytesWritten + written;
102        }
103    }
104
105    /**
106     * Creates an archive entry using the inputFile and entryName provided.
107     *
108     * @param inputFile the file to create the entry from
109     * @param entryName name to use for the entry
110     * @return the ArchiveEntry set up with details from the file
111     *
112     * @throws IOException if an I/O error occurs
113     */
114    public abstract E createArchiveEntry(File inputFile, String entryName) throws IOException;
115
116    /**
117     * Creates an archive entry using the inputPath and entryName provided.
118     * <p>
119     * The default implementation calls simply delegates as:
120     * </p>
121     * <pre>return createArchiveEntry(inputFile.toFile(), entryName);</pre>
122     * <p>
123     * Subclasses should override this method.
124     * </p>
125     *
126     * @param inputPath the file to create the entry from
127     * @param entryName name to use for the entry
128     * @param options options indicating how symbolic links are handled.
129     * @return the ArchiveEntry set up with details from the file
130     *
131     * @throws IOException if an I/O error occurs
132     * @since 1.21
133     */
134    public E createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
135        return createArchiveEntry(inputPath.toFile(), entryName);
136    }
137
138    /**
139     * Finishes the addition of entries to this stream, without closing it.
140     * Additional data can be written, if the format supports it.
141     *
142     * @throws IOException if the user forgets to close the entry.
143     */
144    public abstract void finish() throws IOException;
145
146    /**
147     * Gets the current number of bytes written to this stream.
148     *
149     * @return the number of written bytes
150     * @since 1.1
151     */
152    public long getBytesWritten() {
153        return bytesWritten;
154    }
155
156    /**
157     * Gets the current number of bytes written to this stream.
158     *
159     * @return the number of written bytes
160     * @deprecated this method may yield wrong results for large
161     * archives, use #getBytesWritten instead
162     */
163    @Deprecated
164    public int getCount() {
165        return (int) bytesWritten;
166    }
167
168    /**
169     * Writes the headers for an archive entry to the output stream.
170     * The caller must then write the content to the stream and call
171     * {@link #closeArchiveEntry()} to complete the process.
172     *
173     * @param entry describes the entry
174     * @throws IOException if an I/O error occurs
175     */
176    public abstract void putArchiveEntry(E entry) throws IOException;
177
178    /**
179     * Writes a byte to the current archive entry.
180     *
181     * <p>This method simply calls {@code write( byte[], 0, 1 )}.
182     *
183     * <p>MUST be overridden if the {@link #write(byte[], int, int)} method
184     * is not overridden; may be overridden otherwise.
185     *
186     * @param b The byte to be written.
187     * @throws IOException on error
188     */
189    @Override
190    public void write(final int b) throws IOException {
191        oneByte[0] = (byte) (b & BYTE_MASK);
192        write(oneByte, 0, 1);
193    }
194}