Code to read and write Base64-encoded text.
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//package flex.messaging.util;
/**
* Code to read and write Base64-encoded text.
* Fairly special-purpose, not quite ready for
* general streaming as they don't let you
* drain less than everything that is currently
* available.
*
* @exclude
*/
public class Hex
{
private static final char digits[] =
{
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
public static class Decoder
{
private int filled = 0;
private byte data[];
private int work[] = {0, 0};
public Decoder()
{
data = new byte[256];
}
public void decode(String encoded)
{
int estimate = 1 + encoded.length() / 2;
if (filled + estimate > data.length)
{
int length = data.length * 2;
while (length < filled + estimate)
{
length *= 2;
}
byte[] newdata = new byte[length];
System.arraycopy(data, 0, newdata, 0, filled);
data = newdata;
}
for (int i = 0; i < encoded.length(); ++i)
{
work[0] = Character.digit(encoded.charAt(i), 16);
i++;
work[1] = Character.digit(encoded.charAt(i), 16);
data[filled++] = (byte) (((work[0] << 4) | (work[1])) & 0xff);
}
}
public byte[] drain()
{
byte[] r = new byte[filled];
System.arraycopy(data, 0, r, 0, filled);
filled = 0;
return r;
}
public byte[] flush() throws IllegalStateException
{
return drain();
}
public void reset()
{
filled = 0;
}
}
public static class Encoder
{
private StringBuffer output;
public Encoder(int size)
{
output = new StringBuffer(size * 2);
}
private void encodeBlock(byte work)
{
output.append(digits[(work & 0xF0) >>> 4]);
output.append(digits[(work & 0x0F)]);
}
public void encode(byte[] data)
{
encode(data, 0, data.length);
}
public void encode(byte[] data, int offset, int length)
{
int plainIndex = offset;
while (plainIndex < (offset + length))
{
encodeBlock(data[plainIndex]);
plainIndex++;
}
}
public String drain()
{
String r = output.toString();
output.setLength(0);
return r;
}
public String flush()
{
return drain();
}
}
public static void main(String[] args)
{
boolean printData = false;
int randomLimit = 500;
for (int myCount = 0; myCount < 10000; myCount++)
{
byte raw [] = new byte[(int)(Math.random() * randomLimit)];
for (int i = 0; i < raw.length; ++i)
{
if ((i % 1024) < 256)
raw[i] = (byte)(i % 1024);
else
raw[i] = (byte)((int)(Math.random() * 255) - 128);
}
Hex.Encoder encoder = new Hex.Encoder(100);
encoder.encode(raw);
String encoded = encoder.drain();
Hex.Decoder decoder = new Hex.Decoder();
decoder.decode(encoded);
byte check[] = decoder.flush();
String mesg = "Success!";
if (check.length != raw.length)
{
mesg = "***** length mismatch!";
}
else
{
for (int i = 0; i < check.length; ++i)
{
if (check[i] != raw[i])
{
mesg = "***** data mismatch!";
break;
}
}
}
if (mesg.indexOf("Success") == -1)
{
System.out.println(mesg + myCount);
break;
}
if (printData)
{
System.out.println("Decoded: " + new String(raw));
System.out.println("Encoded: " + encoded);
System.out.println("Decoded: " + new String(check));
}
}
}
}
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