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}