org.base64coder.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
//
// Please contact the author if you need another license.
// This module is provided "as is", without warranties of any kind.
package org.base64coder;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
/**
* 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.
*/
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 {
Arrays.fill(map2, (byte) -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) {
try {
return new String(encode(s.getBytes("UTF-8")));
} catch (UnsupportedEncodingException ex) {
throw new RuntimeException(ex);
}
}
/**
* 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