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Base64.javaAPI DocJCIFS 1.3.17 API3921Tue Oct 18 15:26:24 BST 2011jcifs.util

Base64

public class Base64 extends Object

Fields Summary
private static final String
ALPHABET
Constructors Summary
Methods Summary
public static byte[]decode(java.lang.String string)
Decodes the supplied Base-64 encoded string.

param
string The Base-64 encoded string that is to be decoded.
return
A byte[] containing the decoded data block.

        int length = string.length();
        if (length == 0) return new byte[0];
        int pad = (string.charAt(length - 2) == '=") ? 2 :
                (string.charAt(length - 1) == '=") ? 1 : 0;
        int size = length * 3 / 4 - pad;
        byte[] buffer = new byte[size];
        int block;
        int i = 0;
        int index = 0;
        while (i < length) {
            block = (ALPHABET.indexOf(string.charAt(i++)) & 0xff) << 18 |
                    (ALPHABET.indexOf(string.charAt(i++)) & 0xff) << 12 |
                    (ALPHABET.indexOf(string.charAt(i++)) & 0xff) << 6 |
                    (ALPHABET.indexOf(string.charAt(i++)) & 0xff);
            buffer[index++] = (byte) (block >>> 16);
            if (index < size) buffer[index++] = (byte) ((block >>> 8) & 0xff);
            if (index < size) buffer[index++] = (byte) (block & 0xff);
        }
        return buffer;
public static java.lang.Stringencode(byte[] bytes)
Base-64 encodes the supplied block of data. Line wrapping is not applied on output.

param
bytes The block of data that is to be Base-64 encoded.
return
A String containing the encoded data.


                                           
         
        int length = bytes.length;
        if (length == 0) return "";
        StringBuffer buffer =
                new StringBuffer((int) Math.ceil((double) length / 3d) * 4);
        int remainder = length % 3;
        length -= remainder;
        int block;
        int i = 0;
        while (i < length) {
            block = ((bytes[i++] & 0xff) << 16) | ((bytes[i++] & 0xff) << 8) |
                    (bytes[i++] & 0xff);
            buffer.append(ALPHABET.charAt(block >>> 18));
            buffer.append(ALPHABET.charAt((block >>> 12) & 0x3f));
            buffer.append(ALPHABET.charAt((block >>> 6) & 0x3f));
            buffer.append(ALPHABET.charAt(block & 0x3f));
        }
        if (remainder == 0) return buffer.toString();
        if (remainder == 1) {
            block = (bytes[i] & 0xff) << 4;
            buffer.append(ALPHABET.charAt(block >>> 6));
            buffer.append(ALPHABET.charAt(block & 0x3f));
            buffer.append("==");
            return buffer.toString();
        }
        block = (((bytes[i++] & 0xff) << 8) | ((bytes[i]) & 0xff)) << 2;
        buffer.append(ALPHABET.charAt(block >>> 12));
        buffer.append(ALPHABET.charAt((block >>> 6) & 0x3f));
        buffer.append(ALPHABET.charAt(block & 0x3f));
        buffer.append("=");
        return buffer.toString();