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API de l'application modulaire evasion-en-ligne
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.evasion.sam.codec;
import java.io.UnsupportedEncodingException;
/**
* Hex encoder and decoder. The charset used for certain operation can be set, the default is set in
* {@link #DEFAULT_CHARSET_NAME}
*
* @since 1.1
* @author Apache Software Foundation
* @version $Id: Hex.java 801639 2009-08-06 13:15:10Z niallp $
*/
public class Hex {
/**
* Default charset name is {@link CharEncoding#UTF_8}
*/
public static final String DEFAULT_CHARSET_NAME = "UTF-8";
/**
* Used to build output as Hex
*/
private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
/**
* Used to build output as Hex
*/
private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @return A char[] containing hexadecimal characters
*/
public static char[] encodeHex(byte[] data) {
return encodeHex(data, true);
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @param toLowerCase
* true converts to lowercase, false to uppercase
* @return A char[] containing hexadecimal characters
* @since 1.4
*/
public static char[] encodeHex(byte[] data, boolean toLowerCase) {
return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @param toDigits
* the output alphabet
* @return A char[] containing hexadecimal characters
* @since 1.4
*/
protected static char[] encodeHex(byte[] data, char[] toDigits) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
out[j++] = toDigits[0x0F & data[i]];
}
return out;
}
/**
* Converts an array of bytes into a String representing the hexadecimal values of each byte in order. The returned
* String will be double the length of the passed array, as it takes two characters to represent any given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @return A String containing hexadecimal characters
* @since 1.4
*/
public static String encodeHexString(byte[] data) {
return new String(encodeHex(data));
}
private final String charsetName;
/**
* Creates a new codec with the default charset name {@link #DEFAULT_CHARSET_NAME}
*/
public Hex() {
// use default encoding
this.charsetName = DEFAULT_CHARSET_NAME;
}
/**
* Creates a new codec with the given charset name.
*
* @param csName
* the charset name.
* @since 1.4
*/
public Hex(String csName) {
this.charsetName = csName;
}
/**
* Converts an array of bytes into an array of bytes for the characters representing the hexadecimal values of each
* byte in order. The returned array will be double the length of the passed array, as it takes two characters to
* represent any given byte.
*
* The conversion from hexadecimal characters to the returned bytes is performed with the charset named by
* {@link #getCharsetName()}.
*
*
* @param array
* a byte[] to convert to Hex characters
* @return A byte[] containing the bytes of the hexadecimal characters
* @throws IllegalStateException
* if the charsetName is invalid. This API throws {@link IllegalStateException} instead of
* {@link UnsupportedEncodingException} for backward compatibility.
* @see #encodeHex(byte[])
*/
public byte[] encode(byte[] array) {
return getBytesUnchecked(encodeHexString(array), getCharsetName());
}
/**
* Encodes the given string into a sequence of bytes using the named charset, storing the result into a new byte
* array.
*
* This method catches {@link UnsupportedEncodingException} and rethrows it as {@link IllegalStateException}, which
* should never happen for a required charset name. Use this method when the encoding is required to be in the JRE.
*
*
* @param string
* the String to encode
* @param charsetName
* The name of a required {@link java.nio.charset.Charset}
* @return encoded bytes
* @throws IllegalStateException
* Thrown when a {@link UnsupportedEncodingException} is caught, which should never happen for a
* required charset name.
* @see CharEncoding
* @see String#getBytes(String)
*/
public static byte[] getBytesUnchecked(String string, String charsetName) {
if (string == null) {
return null;
}
try {
return string.getBytes(charsetName);
} catch (UnsupportedEncodingException e) {
throw newIllegalStateException(charsetName, e);
}
}
private static IllegalStateException newIllegalStateException(String charsetName, UnsupportedEncodingException e) {
return new IllegalStateException(charsetName + ": " + e);
}
/**
* Converts a String or an array of bytes into an array of characters representing the hexadecimal values of each
* byte in order. The returned array will be double the length of the passed String or array, as it takes two
* characters to represent any given byte.
*
* The conversion from hexadecimal characters to bytes to be encoded to performed with the charset named by
* {@link #getCharsetName()}.
*
*
* @param object
* a String, or byte[] to convert to Hex characters
* @return A char[] containing hexadecimal characters
* @throws EncoderException
* Thrown if the given object is not a String or byte[]
* @see #encodeHex(byte[])
*/
public Object encode(Object object) throws EncoderException {
try {
byte[] byteArray = object instanceof String ? ((String) object).getBytes(getCharsetName()) : (byte[]) object;
return encodeHex(byteArray);
} catch (ClassCastException e) {
throw new EncoderException(e.getMessage(), e);
} catch (UnsupportedEncodingException e) {
throw new EncoderException(e.getMessage(), e);
}
}
/**
* Gets the charset name.
*
* @return the charset name.
* @since 1.4
*/
public String getCharsetName() {
return this.charsetName;
}
/**
* Returns a string representation of the object, which includes the charset name.
*
* @return a string representation of the object.
*/
public String toString() {
return super.toString() + "[charsetName=" + this.charsetName + "]";
}
}