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 /** Temporary buffer used for the {@link #write(int)} method */ 052 private final byte[] oneByte = new byte[1]; 053 static final int BYTE_MASK = 0xFF; 054 055 /** holds the number of bytes written to this stream */ 056 private long bytesWritten; 057 // Methods specific to ArchiveOutputStream 058 059 /** 060 * Writes the headers for an archive entry to the output stream. 061 * The caller must then write the content to the stream and call 062 * {@link #closeArchiveEntry()} to complete the process. 063 * 064 * @param entry describes the entry 065 * @throws IOException if an I/O error occurs 066 */ 067 public abstract void putArchiveEntry(ArchiveEntry entry) throws IOException; 068 069 /** 070 * Closes the archive entry, writing any trailer information that may 071 * be required. 072 * @throws IOException if an I/O error occurs 073 */ 074 public abstract void closeArchiveEntry() throws IOException; 075 076 /** 077 * Finishes the addition of entries to this stream, without closing it. 078 * Additional data can be written, if the format supports it. 079 * 080 * @throws IOException if the user forgets to close the entry. 081 */ 082 public abstract void finish() throws IOException; 083 084 /** 085 * Create an archive entry using the inputFile and entryName provided. 086 * 087 * @param inputFile the file to create the entry from 088 * @param entryName name to use for the entry 089 * @return the ArchiveEntry set up with details from the file 090 * 091 * @throws IOException if an I/O error occurs 092 */ 093 public abstract ArchiveEntry createArchiveEntry(File inputFile, String entryName) throws IOException; 094 095 /** 096 * Create an archive entry using the inputPath and entryName provided. 097 * 098 * The default implementation calls simply delegates as: 099 * <pre>return createArchiveEntry(inputFile.toFile(), entryName);</pre> 100 * 101 * Subclasses should override this method. 102 * 103 * @param inputPath the file to create the entry from 104 * @param entryName name to use for the entry 105 * @param options options indicating how symbolic links are handled. 106 * @return the ArchiveEntry set up with details from the file 107 * 108 * @throws IOException if an I/O error occurs 109 * @since 1.21 110 */ 111 public ArchiveEntry createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException { 112 return createArchiveEntry(inputPath.toFile(), entryName); 113 } 114 115 // Generic implementations of OutputStream methods that may be useful to sub-classes 116 117 /** 118 * Writes a byte to the current archive entry. 119 * 120 * <p>This method simply calls {@code write( byte[], 0, 1 )}. 121 * 122 * <p>MUST be overridden if the {@link #write(byte[], int, int)} method 123 * is not overridden; may be overridden otherwise. 124 * 125 * @param b The byte to be written. 126 * @throws IOException on error 127 */ 128 @Override 129 public void write(final int b) throws IOException { 130 oneByte[0] = (byte) (b & BYTE_MASK); 131 write(oneByte, 0, 1); 132 } 133 134 /** 135 * Increments the counter of already written bytes. 136 * Doesn't increment if EOF has been hit ({@code written == -1}). 137 * 138 * @param written the number of bytes written 139 */ 140 protected void count(final int written) { 141 count((long) written); 142 } 143 144 /** 145 * Increments the counter of already written bytes. 146 * Doesn't increment if EOF has been hit ({@code written == -1}). 147 * 148 * @param written the number of bytes written 149 * @since 1.1 150 */ 151 protected void count(final long written) { 152 if (written != -1) { 153 bytesWritten = bytesWritten + written; 154 } 155 } 156 157 /** 158 * Returns the current number of bytes written to this stream. 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 * Returns the current number of bytes written to this stream. 170 * @return the number of written bytes 171 * @since 1.1 172 */ 173 public long getBytesWritten() { 174 return bytesWritten; 175 } 176 177 /** 178 * Whether this stream is able to write the given entry. 179 * 180 * <p>Some archive formats support variants or details that are 181 * not supported (yet).</p> 182 * 183 * @param archiveEntry 184 * the entry to test 185 * @return This implementation always returns true. 186 * @since 1.1 187 */ 188 public boolean canWriteEntryData(final ArchiveEntry archiveEntry) { 189 return true; 190 } 191}