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 */
049public abstract class ArchiveOutputStream extends OutputStream {
050
051    static final int BYTE_MASK = 0xFF;
052    /** Temporary buffer used for the {@link #write(int)} method */
053    private final byte[] oneByte = new byte[1];
054
055    /** holds the number of bytes written to this stream */
056    private long bytesWritten;
057    // Methods specific to ArchiveOutputStream
058
059    /**
060     * Whether this stream is able to write the given entry.
061     *
062     * <p>Some archive formats support variants or details that are
063     * not supported (yet).</p>
064     *
065     * @param archiveEntry
066     *            the entry to test
067     * @return This implementation always returns true.
068     * @since 1.1
069     */
070    public boolean canWriteEntryData(final ArchiveEntry archiveEntry) {
071        return true;
072    }
073
074    /**
075     * Closes the archive entry, writing any trailer information that may
076     * be required.
077     * @throws IOException if an I/O error occurs
078     */
079    public abstract void closeArchiveEntry() throws IOException;
080
081    /**
082     * Increments the counter of already written bytes.
083     * Doesn't increment if EOF has been hit ({@code written == -1}).
084     *
085     * @param written the number of bytes written
086     */
087    protected void count(final int written) {
088        count((long) written);
089    }
090
091    /**
092     * Increments the counter of already written bytes.
093     * 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 = bytesWritten + written;
101        }
102    }
103
104    /**
105     * Create 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 ArchiveEntry createArchiveEntry(File inputFile, String entryName) throws IOException;
114
115    // Generic implementations of OutputStream methods that may be useful to sub-classes
116
117    /**
118     * Create an archive entry using the inputPath and entryName provided.
119     *
120     * The default implementation calls simply delegates as:
121     * <pre>return createArchiveEntry(inputFile.toFile(), entryName);</pre>
122     *
123     * Subclasses should override this method.
124     *
125     * @param inputPath the file to create the entry from
126     * @param entryName name to use for the entry
127     * @param options options indicating how symbolic links are handled.
128     * @return the ArchiveEntry set up with details from the file
129     *
130     * @throws IOException if an I/O error occurs
131     * @since 1.21
132     */
133    public ArchiveEntry createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
134        return createArchiveEntry(inputPath.toFile(), entryName);
135    }
136
137    /**
138     * Finishes the addition of entries to this stream, without closing it.
139     * Additional data can be written, if the format supports it.
140     *
141     * @throws IOException if the user forgets to close the entry.
142     */
143    public abstract void finish() throws IOException;
144
145    /**
146     * Returns the current number of bytes written to this stream.
147     * @return the number of written bytes
148     * @since 1.1
149     */
150    public long getBytesWritten() {
151        return bytesWritten;
152    }
153
154    /**
155     * Returns the current number of bytes written to this stream.
156     * @return the number of written bytes
157     * @deprecated this method may yield wrong results for large
158     * archives, use #getBytesWritten instead
159     */
160    @Deprecated
161    public int getCount() {
162        return (int) bytesWritten;
163    }
164
165    /**
166     * Writes the headers for an archive entry to the output stream.
167     * The caller must then write the content to the stream and call
168     * {@link #closeArchiveEntry()} to complete the process.
169     *
170     * @param entry describes the entry
171     * @throws IOException if an I/O error occurs
172     */
173    public abstract void putArchiveEntry(ArchiveEntry entry) throws IOException;
174
175    /**
176     * Writes a byte to the current archive entry.
177     *
178     * <p>This method simply calls {@code write( byte[], 0, 1 )}.
179     *
180     * <p>MUST be overridden if the {@link #write(byte[], int, int)} method
181     * is not overridden; may be overridden otherwise.
182     *
183     * @param b The byte to be written.
184     * @throws IOException on error
185     */
186    @Override
187    public void write(final int b) throws IOException {
188        oneByte[0] = (byte) (b & BYTE_MASK);
189        write(oneByte, 0, 1);
190    }
191}