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package org.apache.commons.compress.archivers.zip;

import java.io.IOException;
import java.nio.ByteBuffer;

An interface for encoders that do a pretty encoding of ZIP filenames.

There are mostly two implementations, one that uses java.nio Charset and one implementation, which copes with simple 8 bit charsets, because java-1.4 did not support Cp437 in java.nio.

The main reason for defining an own encoding layer comes from the problems with String.getBytes, which encodes unknown characters as ASCII quotation marks ('?'). Quotation marks are per definition an invalid filename on some operating systems like Windows, which leads to ignored ZIP entries.

All implementations should implement this interface in a reentrant way.

/** * An interface for encoders that do a pretty encoding of ZIP * filenames. * * <p>There are mostly two implementations, one that uses java.nio * {@link java.nio.charset.Charset Charset} and one implementation, * which copes with simple 8 bit charsets, because java-1.4 did not * support Cp437 in java.nio.</p> * * <p>The main reason for defining an own encoding layer comes from * the problems with {@link java.lang.String#getBytes(String) * String.getBytes}, which encodes unknown characters as ASCII * quotation marks ('?'). Quotation marks are per definition an * invalid filename on some operating systems like Windows, which * leads to ignored ZIP entries.</p> * * <p>All implementations should implement this interface in a * reentrant way.</p> */
public interface ZipEncoding {
Check, whether the given string may be losslessly encoded using this encoding.
Params:
  • name – A filename or ZIP comment.
Returns:Whether the given name may be encoded with out any losses.
/** * Check, whether the given string may be losslessly encoded using this * encoding. * * @param name A filename or ZIP comment. * @return Whether the given name may be encoded with out any losses. */
boolean canEncode(String name);
Encode a filename or a comment to a byte array suitable for storing it to a serialized zip entry.

Examples for CP 437 (in pseudo-notation, right hand side is C-style notation):

 encode("\u20AC_for_Dollar.txt") = "%U20AC_for_Dollar.txt"
 encode("\u00D6lf\u00E4sser.txt") = "\231lf\204sser.txt"
Params:
  • name – A filename or ZIP comment.
Throws:
Returns:A byte buffer with a backing array containing the encoded name. Unmappable characters or malformed character sequences are mapped to a sequence of utf-16 words encoded in the format %Uxxxx. It is assumed, that the byte buffer is positioned at the beginning of the encoded result, the byte buffer has a backing array and the limit of the byte buffer points to the end of the encoded result.
/** * Encode a filename or a comment to a byte array suitable for * storing it to a serialized zip entry. * * <p>Examples for CP 437 (in pseudo-notation, right hand side is * C-style notation):</p> * <pre> * encode("\u20AC_for_Dollar.txt") = "%U20AC_for_Dollar.txt" * encode("\u00D6lf\u00E4sser.txt") = "\231lf\204sser.txt" * </pre> * * @param name A filename or ZIP comment. * @return A byte buffer with a backing array containing the * encoded name. Unmappable characters or malformed * character sequences are mapped to a sequence of utf-16 * words encoded in the format <code>%Uxxxx</code>. It is * assumed, that the byte buffer is positioned at the * beginning of the encoded result, the byte buffer has a * backing array and the limit of the byte buffer points * to the end of the encoded result. * @throws IOException on error */
ByteBuffer encode(String name) throws IOException;
Params:
  • data – The byte values to decode.
Throws:
Returns:The decoded string.
/** * @param data The byte values to decode. * @return The decoded string. * @throws IOException on error */
String decode(byte [] data) throws IOException; }