package com.sun.syndication.io.impl;
/*
* Copyright 2004 Sun Microsystems, Inc.
*
* Licensed 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.
*
*/
/**
* Encodes/decodes byte arrays and Strings into/from a base 64 String.
* <p>
* @author Alejandro Abdelnur
*
*/
public class Base64 {
/**
* Encodes a String into a base 64 String. The resulting encoding is chunked at 76 bytes.
* <p>
* @param s String to encode.
* @return encoded string.
*
*/
public static String encode(String s) {
byte[] sBytes = s.getBytes();
sBytes = encode(sBytes);
s = new String(sBytes);
return s;
}
/**
* Decodes a base 64 String into a String.
* <p>
* @param s String to decode.
* @return encoded string.
* @throws java.lang.IllegalArgumentException thrown if the given byte array was not valid com.sun.syndication.io.impl.Base64 encoding.
*
*/
public static String decode(String s) throws IllegalArgumentException {
s = s.replaceAll("\n", "");
s = s.replaceAll("\r", "");
byte[] sBytes = s.getBytes();
sBytes = decode(sBytes);
s = new String(sBytes);
return s;
}
private static final byte[] ALPHASET =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".getBytes();
private static final int I6O2 = 255 - 3;
private static final int O6I2 = 3;
private static final int I4O4 = 255 - 15;
private static final int O4I4 = 15;
private static final int I2O6 = 255 - 63;
private static final int O2I6 = 63;
/**
* Encodes a byte array into a base 64 byte array.
* <p>
* @param dData byte array to encode.
* @return encoded byte array.
*
*/
public static byte[] encode(byte[] dData) {
if (dData==null) {
throw new IllegalArgumentException("Cannot encode null");
}
byte[] eData = new byte[((dData.length+2)/3)*4];
int eIndex = 0;
for (int i = 0; i<dData.length; i += 3) {
int d1;
int d2=0;
int d3=0;
int e1;
int e2;
int e3;
int e4;
int pad=0;
d1 = dData[i];
if ((i+1)<dData.length) {
d2 = dData[i+1];
if ((i+2)<dData.length) {
d3 = dData[i+2];
}
else {
pad =1;
}
}
else {
pad =2;
}
e1 = ALPHASET[(d1&I6O2)>>2];
e2 = ALPHASET[(d1&O6I2)<<4 | (d2&I4O4)>>4];
e3 = ALPHASET[(d2&O4I4)<<2 | (d3&I2O6)>>6];
e4 = ALPHASET[(d3&O2I6)];
eData[eIndex++] = (byte)e1;
eData[eIndex++] = (byte)e2;
eData[eIndex++] = (pad<2) ?(byte)e3 : (byte)'=';
eData[eIndex++] = (pad<1) ?(byte)e4 : (byte)'=';
}
return eData;
}
private final static int[] CODES = new int[256];
static {
for (int i=0;i<CODES.length;i++) {
CODES[i] = 64;
}
for (int i=0;i<ALPHASET.length;i++) {
CODES[ALPHASET[i]] = i;
}
}
/**
* Dencodes a com.sun.syndication.io.impl.Base64 byte array.
* <p>
* @param eData byte array to decode.
* @return decoded byte array.
* @throws java.lang.IllegalArgumentException thrown if the given byte array was not valid com.sun.syndication.io.impl.Base64 encoding.
*
*/
public static byte[] decode(byte[] eData) {
if (eData==null) {
throw new IllegalArgumentException("Cannot decode null");
}
byte[] cleanEData = (byte[]) eData.clone();
int cleanELength = 0;
for (int i=0;i<eData.length;i++) {
if (eData[i]<256 && CODES[eData[i]]<64) {
cleanEData[cleanELength++] = eData[i];
}
}
int dLength = (cleanELength/4)*3;
switch (cleanELength%4) {
case 3:
dLength += 2;
break;
case 2:
dLength++;
break;
}
byte[] dData = new byte[dLength];
int dIndex = 0;
for (int i = 0; i < eData.length; i += 4) {
if ((i + 3) > eData.length) {
throw new IllegalArgumentException("byte array is not a valid com.sun.syndication.io.impl.Base64 encoding");
}
int e1 = CODES[cleanEData[i]];
int e2 = CODES[cleanEData[i+1]];
int e3 = CODES[cleanEData[i+2]];
int e4 = CODES[cleanEData[i+3]];
dData[dIndex++] = (byte) ((e1<<2)|(e2>>4));
if (dIndex<dData.length) {
dData[dIndex++] = (byte) ((e2<<4) | (e3>>2));
}
if (dIndex<dData.length) {
dData[dIndex++] = (byte) ((e3<<6) | (e4));
}
}
return dData;
}
public static void main(String[] args) throws Exception {
String s =
"\nPGRpdiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMTk5OS94aHRtbCI+V2UncmUgcHJvcG9zaW5nIDxhIGhy\n"+
"ZWY9Imh0dHA6Ly93d3cuZ29vZ2xlLmNvbS9jb3Jwb3JhdGUvc29mdHdhcmVfcHJpbmNpcGxlcy5odG1sIj5z\n"+
"b21lIGd1aWRlbGluZXMgPC9hPnRvIGhlbHAgY3VyYiB0aGUgcHJvYmxlbSBvZiBJbnRlcm5ldCBzb2Z0d2Fy\n"+
"ZSB0aGF0IGluc3RhbGxzIGl0c2VsZiB3aXRob3V0IHRlbGxpbmcgeW91LCBvciBiZWhhdmVzIGJhZGx5IG9u\n"+
"Y2UgaXQgZ2V0cyBvbiB5b3VyIGNvbXB1dGVyLiBXZSd2ZSBiZWVuIGhlYXJpbmcgYSBsb3Qgb2YgY29tcGxh\n"+
"aW50cyBhYm91dCB0aGlzIGxhdGVseSBhbmQgaXQgc2VlbXMgdG8gYmUgZ2V0dGluZyB3b3JzZS4gV2UgdGhp\n"+
"bmsgaXQncyBpbXBvcnRhbnQgdGhhdCB5b3UgcmV0YWluIGNvbnRyb2wgb2YgeW91ciBjb21wdXRlciBhbmQg\n"+
"dGhhdCB0aGVyZSBiZSBzb21lIGNsZWFyIHN0YW5kYXJkcyBpbiBvdXIgaW5kdXN0cnkuIExldCB1cyBrbm93\n"+
"IGlmIHlvdSB0aGluayB0aGVzZSBndWlkZWxpbmVzIGFyZSB1c2VmdWwgb3IgaWYgeW91IGhhdmUgc3VnZ2Vz\n"+
"dGlvbnMgdG8gaW1wcm92ZSB0aGVtLgo8YnIgLz4KPGJyIC8+Sm9uYXRoYW4gUm9zZW5iZXJnCjxiciAvPgo8\n"+
"L2Rpdj4K\n";
System.out.println(decode(s));
}
}