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PubNub is a cross-platform client-to-client (1:1 and 1:many) push service in the cloud, capable of broadcasting real-time messages to millions of web and mobile clients simultaneously, in less than a quarter second!
package com.pubnub.api;
/**
* Simple base64 encoder, can be implemented in other platforms.
*
*/
class Base64Encoder {
// Mapping table from 6-bit nibbles to Base64 characters.
private static 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 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 with the Base64 encoded data.
*/
public static String encodeString(String s) {
return new String(encode(s.getBytes()));
}
/**
* Encodes a byte array into Base64 format. No blanks or line breaks are
* inserted.
*
* @param in
* an array containing the data bytes to be encoded.
* @return A character array with the Base64 encoded data.
*/
public static char[] encode(byte[] in) {
return encode(in, in.length);
}
/**
* Encodes a byte array into Base64 format. No blanks or line breaks are
* inserted.
*
* @param in
* an array containing the data bytes to be encoded.
* @param iLen
* number of bytes to process in in.
* @return A character array with the Base64 encoded data.
*/
public static char[] encode(byte[] in, 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 = 0;
int op = 0;
while (ip < iLen) {
int i0 = in[ip++] & 0xff;
int i1 = ip < iLen ? in[ip++] & 0xff : 0;
int i2 = ip < iLen ? 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;
}
private static String removeNewLine(String s) {
char[] sa = new char[s.length()];
int j = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) != '\n' && s.charAt(i) != ' ') {
sa[j++] = s.charAt(i);
}
}
return new String(sa).trim();
}
/**
* Decodes a string from Base64 format.
*
* @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.
*
* @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(removeNewLine(s).toCharArray());
}
/**
* Decodes a byte array from Base64 format. No blanks or line breaks are
* allowed within the Base64 encoded 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) {
int iLen = in.length;
if (iLen % 4 != 0)
throw new IllegalArgumentException(
"Length of Base64 encoded input string is not a multiple of 4.");
while (iLen > 0 && in[iLen - 1] == '=')
iLen--;
int oLen = (iLen * 3) / 4;
byte[] out = new byte[oLen];
int ip = 0;
int op = 0;
while (ip < iLen) {
int i0 = in[ip++];
int i1 = in[ip++];
int i2 = ip < iLen ? in[ip++] : 'A';
int i3 = ip < iLen ? 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;
}
/**
* This class is not instantiable.
*/
private Base64Encoder() {
}
} // end class Base64Encoder