main.java.com.dragome.helpers.Base64Coder Maven / Gradle / Ivy
// Copyright 2003-2010 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
// www.source-code.biz, www.inventec.ch/chdh
//
// This module is multi-licensed and may be used under the terms
// of any of the following licenses:
//
// EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal
// LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html
// GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html
// AL, Apache License, V2.0 or later, http://www.apache.org/licenses
// BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php
// MIT, MIT License, http://www.opensource.org/licenses/MIT
//
// Please contact the author if you need another license.
// This module is provided "as is", without warranties of any kind.
package com.dragome.helpers;
/**
* A Base64 encoder/decoder.
*
*
* This class is used to encode and decode data in Base64 format as described in RFC 1521.
*
*
* Project home page: www.source-code.biz/base64coder/java
* Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
* Multi-licensed: EPL / LGPL / GPL / AL / BSD / MIT.
*/
public class Base64Coder
{
// The line separator string of the operating system.
private static final String systemLineSeparator= System.getProperty("line.separator");
// Mapping table from 6-bit nibbles to Base64 characters.
private static final char[] map1= new char[64];
static
{
int i= 0;
for (char c= 'A'; c <= 'Z'; c++)
map1[i++]= c;
for (char c= 'a'; c <= 'z'; c++)
map1[i++]= c;
for (char c= '0'; c <= '9'; c++)
map1[i++]= c;
map1[i++]= '+';
map1[i++]= '/';
}
// Mapping table from Base64 characters to 6-bit nibbles.
private static final byte[] map2= new byte[128];
static
{
for (int i= 0; i < map2.length; i++)
map2[i]= -1;
for (int i= 0; i < 64; i++)
map2[map1[i]]= (byte) i;
}
/**
* Encodes a string into Base64 format.
* No blanks or line breaks are inserted.
* @param s A String to be encoded.
* @return A String containing the Base64 encoded data.
*/
public static String encodeString(String s)
{
return new String(encode(s.getBytes()));
}
/**
* Encodes a byte array into Base 64 format and breaks the output into lines of 76 characters.
* This method is compatible with sun.misc.BASE64Encoder.encodeBuffer(byte[]).
* @param in An array containing the data bytes to be encoded.
* @return A String containing the Base64 encoded data, broken into lines.
*/
public static String encodeLines(byte[] in)
{
return encodeLines(in, 0, in.length, 76, systemLineSeparator);
}
/**
* Encodes a byte array into Base 64 format and breaks the output into lines.
* @param in An array containing the data bytes to be encoded.
* @param iOff Offset of the first byte in in to be processed.
* @param iLen Number of bytes to be processed in in, starting at iOff.
* @param lineLen Line length for the output data. Should be a multiple of 4.
* @param lineSeparator The line separator to be used to separate the output lines.
* @return A String containing the Base64 encoded data, broken into lines.
*/
public static String encodeLines(byte[] in, int iOff, int iLen, int lineLen, String lineSeparator)
{
int blockLen= (lineLen * 3) / 4;
if (blockLen <= 0)
throw new IllegalArgumentException();
int lines= (iLen + blockLen - 1) / blockLen;
int bufLen= ((iLen + 2) / 3) * 4 + lines * lineSeparator.length();
StringBuilder buf= new StringBuilder(bufLen);
int ip= 0;
while (ip < iLen)
{
int l= Math.min(iLen - ip, blockLen);
buf.append(encode(in, iOff + ip, l));
buf.append(lineSeparator);
ip+= l;
}
return buf.toString();
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @return A character array containing the Base64 encoded data.
*/
public static char[] encode(byte[] in)
{
return encode(in, 0, in.length);
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @param iLen Number of bytes to process in in.
* @return A character array containing the Base64 encoded data.
*/
public static char[] encode(byte[] in, int iLen)
{
return encode(in, 0, iLen);
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @param iOff Offset of the first byte in in to be processed.
* @param iLen Number of bytes to process in in, starting at iOff.
* @return A character array containing the Base64 encoded data.
*/
public static char[] encode(byte[] in, int iOff, int iLen)
{
int oDataLen= (iLen * 4 + 2) / 3; // output length without padding
int oLen= ((iLen + 2) / 3) * 4; // output length including padding
char[] out= new char[oLen];
int ip= iOff;
int iEnd= iOff + iLen;
int op= 0;
while (ip < iEnd)
{
int i0= in[ip++] & 0xff;
int i1= ip < iEnd ? in[ip++] & 0xff : 0;
int i2= ip < iEnd ? in[ip++] & 0xff : 0;
int o0= i0 >>> 2;
int o1= ((i0 & 3) << 4) | (i1 >>> 4);
int o2= ((i1 & 0xf) << 2) | (i2 >>> 6);
int o3= i2 & 0x3F;
out[op++]= map1[o0];
out[op++]= map1[o1];
out[op]= op < oDataLen ? map1[o2] : '=';
op++;
out[op]= op < oDataLen ? map1[o3] : '=';
op++;
}
return out;
}
/**
* Decodes a string from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param s A Base64 String to be decoded.
* @return A String containing the decoded data.
* @throws IllegalArgumentException If the input is not valid Base64 encoded data.
*/
public static String decodeString(String s)
{
return new String(decode(s));
}
/**
* Decodes a byte array from Base64 format and ignores line separators, tabs and blanks.
* CR, LF, Tab and Space characters are ignored in the input data.
* This method is compatible with sun.misc.BASE64Decoder.decodeBuffer(String).
* @param s A Base64 String to be decoded.
* @return An array containing the decoded data bytes.
* @throws IllegalArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] decodeLines(String s)
{
char[] buf= new char[s.length()];
int p= 0;
for (int ip= 0; ip < s.length(); ip++)
{
char c= s.charAt(ip);
if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
buf[p++]= c;
}
return decode(buf, 0, p);
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param s A Base64 String to be decoded.
* @return An array containing the decoded data bytes.
* @throws IllegalArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] decode(String s)
{
return decode(s.toCharArray());
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param in A character array containing the Base64 encoded data.
* @return An array containing the decoded data bytes.
* @throws IllegalArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] decode(char[] in)
{
return decode(in, 0, in.length);
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param in A character array containing the Base64 encoded data.
* @param iOff Offset of the first character in in to be processed.
* @param iLen Number of characters to process in in, starting at iOff.
* @return An array containing the decoded data bytes.
* @throws IllegalArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] decode(char[] in, int iOff, int iLen)
{
if (iLen % 4 != 0)
throw new IllegalArgumentException("Length of Base64 encoded input string is not a multiple of 4.");
while (iLen > 0 && in[iOff + iLen - 1] == '=')
iLen--;
int oLen= (iLen * 3) / 4;
byte[] out= new byte[oLen];
int ip= iOff;
int iEnd= iOff + iLen;
int op= 0;
while (ip < iEnd)
{
int i0= in[ip++];
int i1= in[ip++];
int i2= ip < iEnd ? in[ip++] : 'A';
int i3= ip < iEnd ? in[ip++] : 'A';
if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)
throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
int b0= map2[i0];
int b1= map2[i1];
int b2= map2[i2];
int b3= map2[i3];
if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
int o0= (b0 << 2) | (b1 >>> 4);
int o1= ((b1 & 0xf) << 4) | (b2 >>> 2);
int o2= ((b2 & 3) << 6) | b3;
out[op++]= (byte) o0;
if (op < oLen)
out[op++]= (byte) o1;
if (op < oLen)
out[op++]= (byte) o2;
}
return out;
}
// Dummy constructor.
private Base64Coder()
{
}
} // end class Base64Coder