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Apache Commons Compress defines an API for working with
compression and archive formats. These include bzip2, gzip, pack200,
LZMA, XZ, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4,
Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.commons.compress.archivers.zip;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.compress.utils.Charsets;
/**
* Static helper functions for robustly encoding filenames in zip files.
*/
public abstract class ZipEncodingHelper {
/**
* A class, which holds the high characters of a simple encoding
* and lazily instantiates a Simple8BitZipEncoding instance in a
* thread-safe manner.
*/
private static class SimpleEncodingHolder {
private final char [] highChars;
private Simple8BitZipEncoding encoding;
/**
* Instantiate a simple encoding holder.
*
* @param highChars The characters for byte codes 128 to 255.
*
* @see Simple8BitZipEncoding#Simple8BitZipEncoding(char[])
*/
SimpleEncodingHolder(final char [] highChars) {
this.highChars = highChars;
}
/**
* @return The associated {@link Simple8BitZipEncoding}, which
* is instantiated if not done so far.
*/
public synchronized Simple8BitZipEncoding getEncoding() {
if (this.encoding == null) {
this.encoding = new Simple8BitZipEncoding(this.highChars);
}
return this.encoding;
}
}
private static final Map simpleEncodings;
static {
final Map se =
new HashMap<>();
final char[] cp437_high_chars =
new char[] { 0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0,
0x00e5, 0x00e7, 0x00ea, 0x00eb, 0x00e8, 0x00ef,
0x00ee, 0x00ec, 0x00c4, 0x00c5, 0x00c9, 0x00e6,
0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5,
0x20a7, 0x0192, 0x00e1, 0x00ed, 0x00f3, 0x00fa,
0x00f1, 0x00d1, 0x00aa, 0x00ba, 0x00bf, 0x2310,
0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561,
0x2562, 0x2556, 0x2555, 0x2563, 0x2551, 0x2557,
0x255d, 0x255c, 0x255b, 0x2510, 0x2514, 0x2534,
0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f,
0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550,
0x256c, 0x2567, 0x2568, 0x2564, 0x2565, 0x2559,
0x2558, 0x2552, 0x2553, 0x256b, 0x256a, 0x2518,
0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580,
0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3,
0x00b5, 0x03c4, 0x03a6, 0x0398, 0x03a9, 0x03b4,
0x221e, 0x03c6, 0x03b5, 0x2229, 0x2261, 0x00b1,
0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248,
0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2,
0x25a0, 0x00a0 };
final SimpleEncodingHolder cp437 = new SimpleEncodingHolder(cp437_high_chars);
se.put("CP437", cp437);
se.put("Cp437", cp437);
se.put("cp437", cp437);
se.put("IBM437", cp437);
se.put("ibm437", cp437);
final char[] cp850_high_chars =
new char[] { 0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0,
0x00e5, 0x00e7, 0x00ea, 0x00eb, 0x00e8, 0x00ef,
0x00ee, 0x00ec, 0x00c4, 0x00c5, 0x00c9, 0x00e6,
0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
0x00ff, 0x00d6, 0x00dc, 0x00f8, 0x00a3, 0x00d8,
0x00d7, 0x0192, 0x00e1, 0x00ed, 0x00f3, 0x00fa,
0x00f1, 0x00d1, 0x00aa, 0x00ba, 0x00bf, 0x00ae,
0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x00c1,
0x00c2, 0x00c0, 0x00a9, 0x2563, 0x2551, 0x2557,
0x255d, 0x00a2, 0x00a5, 0x2510, 0x2514, 0x2534,
0x252c, 0x251c, 0x2500, 0x253c, 0x00e3, 0x00c3,
0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550,
0x256c, 0x00a4, 0x00f0, 0x00d0, 0x00ca, 0x00cb,
0x00c8, 0x0131, 0x00cd, 0x00ce, 0x00cf, 0x2518,
0x250c, 0x2588, 0x2584, 0x00a6, 0x00cc, 0x2580,
0x00d3, 0x00df, 0x00d4, 0x00d2, 0x00f5, 0x00d5,
0x00b5, 0x00fe, 0x00de, 0x00da, 0x00db, 0x00d9,
0x00fd, 0x00dd, 0x00af, 0x00b4, 0x00ad, 0x00b1,
0x2017, 0x00be, 0x00b6, 0x00a7, 0x00f7, 0x00b8,
0x00b0, 0x00a8, 0x00b7, 0x00b9, 0x00b3, 0x00b2,
0x25a0, 0x00a0 };
final SimpleEncodingHolder cp850 = new SimpleEncodingHolder(cp850_high_chars);
se.put("CP850", cp850);
se.put("Cp850", cp850);
se.put("cp850", cp850);
se.put("IBM850", cp850);
se.put("ibm850", cp850);
simpleEncodings = Collections.unmodifiableMap(se);
}
/**
* Grow a byte buffer, so it has a minimal capacity or at least
* the double capacity of the original buffer
*
* @param b The original buffer.
* @param newCapacity The minimal requested new capacity.
* @return A byte buffer r with
* r.capacity() = max(b.capacity()*2,newCapacity) and
* all the data contained in b copied to the beginning
* of r.
*
*/
static ByteBuffer growBuffer(final ByteBuffer b, final int newCapacity) {
b.limit(b.position());
b.rewind();
final int c2 = b.capacity() * 2;
final ByteBuffer on = ByteBuffer.allocate(c2 < newCapacity ? newCapacity : c2);
on.put(b);
return on;
}
/**
* The hexadecimal digits 0,...,9,A,...,F encoded as
* ASCII bytes.
*/
private static final byte[] HEX_DIGITS =
new byte [] {
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41,
0x42, 0x43, 0x44, 0x45, 0x46
};
/**
* Append %Uxxxx to the given byte buffer.
* The caller must assure, that bb.remaining()>=6.
*
* @param bb The byte buffer to write to.
* @param c The character to write.
*/
static void appendSurrogate(final ByteBuffer bb, final char c) {
bb.put((byte) '%');
bb.put((byte) 'U');
bb.put(HEX_DIGITS[(c >> 12)&0x0f]);
bb.put(HEX_DIGITS[(c >> 8)&0x0f]);
bb.put(HEX_DIGITS[(c >> 4)&0x0f]);
bb.put(HEX_DIGITS[c & 0x0f]);
}
/**
* name of the encoding UTF-8
*/
static final String UTF8 = "UTF8";
/**
* name of the encoding UTF-8
*/
static final ZipEncoding UTF8_ZIP_ENCODING = new FallbackZipEncoding(UTF8);
/**
* Instantiates a zip encoding.
*
* @param name The name of the zip encoding. Specify {@code null} for
* the platform's default encoding.
* @return A zip encoding for the given encoding name.
*/
public static ZipEncoding getZipEncoding(final String name) {
// fallback encoding is good enough for UTF-8.
if (isUTF8(name)) {
return UTF8_ZIP_ENCODING;
}
if (name == null) {
return new FallbackZipEncoding();
}
final SimpleEncodingHolder h = simpleEncodings.get(name);
if (h!=null) {
return h.getEncoding();
}
try {
final Charset cs = Charset.forName(name);
return new NioZipEncoding(cs);
} catch (final UnsupportedCharsetException e) {
return new FallbackZipEncoding(name);
}
}
/**
* Returns whether a given encoding is UTF-8. If the given name is null, then check the platform's default encoding.
*
* @param charsetName
* If the given name is null, then check the platform's default encoding.
*/
static boolean isUTF8(String charsetName) {
if (charsetName == null) {
// check platform's default encoding
charsetName = Charset.defaultCharset().name();
}
if (Charsets.UTF_8.name().equalsIgnoreCase(charsetName)) {
return true;
}
for (final String alias : Charsets.UTF_8.aliases()) {
if (alias.equalsIgnoreCase(charsetName)) {
return true;
}
}
return false;
}
}
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