    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 {@link #write(byte[], int, int)} method to improve performance. They should also override
    029 * {@link #close()} to ensure that any necessary trailers are added.
    030 *
    031 * <p>
    032 * The normal sequence of calls when working with ArchiveOutputStreams is:
    033 * </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 *
    049 * @param <E> The type of {@link ArchiveEntry} consumed.
    050 */
    051public abstract class ArchiveOutputStream<E extends ArchiveEntry> extends OutputStream {
    052
    053    static final int BYTE_MASK = 0xFF;
    054
    055    /** Temporary buffer used for the {@link #write(int)} method. */
    056    private final byte[] oneByte = new byte[1];
    057
    058    /** Holds the number of bytes written to this stream. */
    059    private long bytesWritten;
    060
    061    /**
    062     * Whether this stream is able to write the given entry.
    063     *
    064     * <p>
    065     * Some archive formats support variants or details that are not supported (yet).
    066     * </p>
    067     *
    068     * @param archiveEntry the entry to test
    069     * @return This implementation always returns true.
    070     * @since 1.1
    071     */
    072    public boolean canWriteEntryData(final ArchiveEntry archiveEntry) {
    073        return true;
    074    }
    075
    076    /**
    077     * Closes the archive entry, writing any trailer information that may be required.
    078     *
    079     * @throws IOException if an I/O error occurs
    080     */
    081    public abstract void closeArchiveEntry() throws IOException;
    082
    083    /**
    084     * Increments the counter of already written bytes. 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. Doesn't increment if EOF has been hit ({@code written == -1}).
    094     *
    095     * @param written the number of bytes written
    096     * @since 1.1
    097     */
    098    protected void count(final long written) {
    099        if (written != -1) {
    100            bytesWritten += written;
    101        }
    102    }
    103
    104    /**
    105     * Creates an archive entry using the inputFile and entryName provided.
    106     *
    107     * @param inputFile the file to create the entry from
    108     * @param entryName name to use for the entry
    109     * @return the ArchiveEntry set up with details from the file
    110     *
    111     * @throws IOException if an I/O error occurs
    112     */
    113    public abstract E createArchiveEntry(File inputFile, String entryName) throws IOException;
    114
    115    /**
    116     * Creates an archive entry using the inputPath and entryName provided.
    117     * <p>
    118     * The default implementation calls simply delegates as:
    119     * </p>
    120     *
    121     * <pre>
    122     * return createArchiveEntry(inputFile.toFile(), entryName);
    123     * </pre>
    124     * <p>
    125     * Subclasses should override this method.
    126     * </p>
    127     *
    128     * @param inputPath the file to create the entry from
    129     * @param entryName name to use for the entry
    130     * @param options   options indicating how symbolic links are handled.
    131     * @return the ArchiveEntry set up with details from the file
    132     *
    133     * @throws IOException if an I/O error occurs
    134     * @since 1.21
    135     */
    136    public E createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
    137        return createArchiveEntry(inputPath.toFile(), entryName);
    138    }
    139
    140    /**
    141     * Finishes the addition of entries to this stream, without closing it. Additional data can be written, if the format supports it.
    142     *
    143     * @throws IOException if the user forgets to close the entry.
    144     */
    145    public abstract void finish() throws IOException;
    146
    147    /**
    148     * Gets the current number of bytes written to this stream.
    149     *
    150     * @return the number of written bytes
    151     * @since 1.1
    152     */
    153    public long getBytesWritten() {
    154        return bytesWritten;
    155    }
    156
    157    /**
    158     * Gets the current number of bytes written to this stream.
    159     *
    160     * @return the number of written bytes
    161     * @deprecated this method may yield wrong results for large 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. The caller must then write the content to the stream and call {@link #closeArchiveEntry()}
    170     * to complete the process.
    171     *
    172     * @param entry describes the entry
    173     * @throws IOException if an I/O error occurs
    174     */
    175    public abstract void putArchiveEntry(E entry) throws IOException;
    176
    177    /**
    178     * Writes a byte to the current archive entry.
    179     *
    180     * <p>
    181     * This method simply calls {@code write( byte[], 0, 1 )}.
    182     *
    183     * <p>
    184     * MUST be overridden if the {@link #write(byte[], int, int)} method 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}