Base64 class

Question

Here is a Base64 class. I'm not the author, but it's not important, the important thing is that you can use it for encode and decode. It's very useful!!!. Enjoy it!!.
package yourPackage;
import java.io.*; // needed only for main() method.
* Provides encoding of raw bytes to base64-encoded characters, and
* decoding of base64 characters to raw bytes.
public class Base64
* returns an array of base64-encoded characters to represent the
* passed data array.
* @param data the array of bytes to encode
* @return base64-coded character array.
static public char[] encode(byte[] data)
char[] out = new char[((data.length + 2) / 3) * 4];
// 3 bytes encode to 4 chars. Output is always an even
// multiple of 4 characters.
for (int i = 0, index = 0; i < data.length; i += 3, index += 4)
boolean quad = false;
boolean trip = false;
int val = (0xFF & (int) data);
val <<= 8;
if ((i + 1) < data.length)
val |= (0xFF & (int) data[i + 1]);
trip = true;
val <<= 8;
if ((i + 2) < data.length)
val |= (0xFF & (int) data[i + 2]);
quad = true;
out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];
val >>= 6;
out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];
val >>= 6;
out[index + 1] = alphabet[val & 0x3F];
val >>= 6;
out[index + 0] = alphabet[val & 0x3F];
return out;
* Decodes a BASE-64 encoded stream to recover the original
* data. White space before and after will be trimmed away,
* but no other manipulation of the input will be performed.
* As of version 1.2 this method will properly handle input
* containing junk characters (newlines and the like) rather
* than throwing an error. It does this by pre-parsing the
* input and generating from that a count of VALID input
* characters.
static public byte[] decode(char[] data)
// as our input could contain non-BASE64 data (newlines,
// whitespace of any sort, whatever) we must first adjust
// our count of USABLE data so that...
// (a) we don't misallocate the output array, and
// (b) think that we miscalculated our data length
// just because of extraneous throw-away junk
int tempLen = data.length;
for (int ix = 0; ix < data.length; ix++)
if ((data[ix] > 255) || codes[data[ix]] < 0)
--tempLen; // ignore non-valid chars and padding
// calculate required length:
// -- 3 bytes for every 4 valid base64 chars
// -- plus 2 bytes if there are 3 extra base64 chars,
// or plus 1 byte if there are 2 extra.
int len = (tempLen / 4) * 3;
if ((tempLen % 4) == 3)
len += 2;
if ((tempLen % 4) == 2)
len += 1;
byte[] out = new byte[len];
int shift = 0; // # of excess bits stored in accum
int accum = 0; // excess bits
int index = 0;
// we now go through the entire array (NOT using the 'tempLen' value)
for (int ix = 0; ix < data.length; ix++)
int value = (data[ix] > 255) ? -1 : codes[data[ix]];
if (value >= 0)// skip over non-code
accum <<= 6; // bits shift up by 6 each time thru
shift += 6; // loop, with new bits being put in
accum |= value; // at the bottom.
if (shift >= 8)// whenever there are 8 or more shifted in,
shift -= 8; // write them out (from the top, leaving any
out[index++] = // excess at the bottom for next iteration.
(byte)((accum >> shift) & 0xff);
// we will also have skipped processing a padding null byte ('=') here;
// these are used ONLY for padding to an even length and do not legally
// occur as encoded data. for this reason we can ignore the fact that
// no index++ operation occurs in that special case: the out[] array is
// initialized to all-zero bytes to start with and that works to our
// advantage in this combination.
// if there is STILL something wrong we just have to throw up now!
if (index != out.length)
throw new Error("Miscalculated data length (wrote " +
index + " instead of " + out.length + ")");
return out;
// code characters for values 0..63
static private char[] alphabet =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=" .toCharArray();
// lookup table for converting base64 characters to value in range 0..63
static private byte[] codes = new byte[256];
static
for (int i = 0; i < 256; i++)
codes[i] = -1;
for (int i = 'A'; i <= 'Z'; i++)
codes[i] = (byte)(i - 'A');
for (int i = 'a'; i <= 'z'; i++)
codes[i] = (byte)(26 + i - 'a');
for (int i = '0'; i <= '9'; i++)
codes[i] = (byte)(52 + i - '0');
codes['+'] = 62;
codes['/'] = 63;
public static void main(String[] args)
boolean decode = false;
if (args.length == 0)
System.out.println("usage: java Base64 [-d[ecode]] filename");
System.exit(0);
for (int i = 0; i < args.length; i++)
if ("-decode".equalsIgnoreCase(args[i]))
decode = true;
else if ("-d".equalsIgnoreCase(args[i]))
decode = true;
String filename = args[args.length - 1];
File file = new File(filename);
if (!file.exists())
System.out.println("Error: file '" + filename + "' doesn't exist!");
System.exit(0);
if (decode)
char[] encoded = readChars(file);
byte[] decoded = decode(encoded);
writeBytes(file, decoded);
else
byte[] decoded = readBytes(file);
char[] encoded = encode(decoded);
writeChars(file, encoded);
* @param file
* @return
private static byte[] readBytes(File file)
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try
InputStream fis = new FileInputStream(file);
InputStream is = new BufferedInputStream(fis);
int count = 0;
byte[] buf = new byte[16384];
while ((count = is.read(buf)) != -1)
if (count > 0)
baos.write(buf, 0, count);
is.close();
catch (Exception e)
e.printStackTrace();
return baos.toByteArray();
* @param file
* @return
private static char[] readChars(File file)
CharArrayWriter caw = new CharArrayWriter();
try
Reader fr = new FileReader(file);
Reader in = new BufferedReader(fr);
int count = 0;
char[] buf = new char[16384];
while ((count = in.read(buf)) != -1)
if (count > 0)
caw.write(buf, 0, count);
in.close();
catch (Exception e)
e.printStackTrace();
return caw.toCharArray();
* @param file
* @param data
private static void writeBytes(File file, byte[] data)
try
OutputStream fos = new FileOutputStream(file);
OutputStream os = new BufferedOutputStream(fos);
os.write(data);
os.close();
catch (Exception e)
e.printStackTrace();
* @param file
* @param data
private static void writeChars(File file, char[] data)
try
Writer fos = new FileWriter(file);
Writer os = new BufferedWriter(fos);
os.write(data);
os.close();
catch (Exception e)
e.printStackTrace();

Answer 1

Ok.
The main reason of my message was that in the beginning I didn't know anything for Base64 class and I needed one for my project. I was looking for it and when I had found it I thought in do post a new topic in this forum to help to the people that they should have the same problem. Now I can see more solutions for this issue.
Thank you very much.
Bye