flex.messaging.util.Base64 Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
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 Base64
{
private static final char alphabet[] =
{
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/'
};
private static final int inverse[] =
{
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
};
/**
* @exclude
*/
public static class Decoder
{
private int filled = 0;
private byte data[];
private int count = 0;
private int work[] = {0, 0, 0, 0};
public Decoder()
{
data = new byte[256];
}
public void decode(String encoded)
{
int estimate = 1 + encoded.length() * 3 / 4;
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)
{
char c = encoded.charAt(i);
if (c == '=')
work[count++] = -1;
else if (inverse[c] != 64)
work[count++] = inverse[c];
else
continue;
if (count == 4)
{
count = 0;
data[filled++] = (byte)((work[0] << 2) | ((work[1] & 0xff) >> 4));
if (work[2] == -1)
break;
data[filled++] = (byte)((work[1] << 4) | ((work[2] & 0xff) >> 2));
if (work[3] == -1)
break;
data[filled++] = (byte)((work[2] << 6) | work[3]);
}
}
}
public byte[] drain()
{
byte[] r = new byte[filled];
System.arraycopy(data, 0, r, 0, filled);
filled = 0;
return r;
}
public byte[] flush() throws IllegalStateException
{
if (count > 0)
throw new IllegalStateException("a partial block (" + count + " of 4 bytes) was dropped, decoded data is probably truncated!");
return drain();
}
public void reset()
{
count = 0;
filled = 0;
}
}
/**
* @exclude
*/
public static class Encoder
{
private int work[] = {0, 0, 0};
private int count = 0;
private int line = 0;
private StringBuffer output;
public Encoder(int size)
{
output = new StringBuffer(size);
}
private void encodeBlock()
{
output.append(alphabet[(work[0] & 0xFF) >> 2]);
output.append(alphabet[((work[0] & 0x03) << 4) | ((work[1] & 0xF0) >> 4)]);
if (count > 1)
output.append(alphabet[((work[1] & 0x0F) << 2) | ((work[2] & 0xC0) >> 6)]);
else
output.append('=');
if (count > 2)
output.append(alphabet[work[2] & 0x3F]);
else
output.append('=');
if ((line += 4) == 76)
{
output.append('\n');
line = 0;
}
}
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))
{
work[count] = data[plainIndex];
count++;
if (count == work.length || ((offset + length) - plainIndex) == 1)
{
encodeBlock();
count = 0;
work[0] = 0;
work[1] = 0;
work[2] = 0;
}
plainIndex++;
}
}
public String drain()
{
String r = output.toString();
output.setLength(0);
return r;
}
public String flush()
{
if (count > 0)
encodeBlock();
String r = drain();
count = 0;
line = 0;
work[0] = 0;
work[1] = 0;
work[2] = 0;
return r;
}
}
}© 2015 - 2024 Weber Informatics LLC | Privacy Policy