/*
*
* 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 org.apache.flex.utils;
/**
* 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.
*/
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
};
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;
}
}
public static class Encoder
{
private int work[] = { 0, 0, 0 };
private int count = 0;
private int line = 0;
private StringBuilder output;
private int wrap = 76;
public Encoder( int size )
{
output = new StringBuilder( size );
}
public Encoder( int size, int wrap )
{
output = new StringBuilder( size );
this.wrap = wrap;
}
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 ( (wrap != -1) && (( line += 4 ) == wrap ))
{
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;
}
}
public static void main(String[] args)
{
boolean printData = false;
int randomLimit = 500;
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);
}
Base64.Encoder encoder = new Base64.Encoder(100);
encoder.encode( raw );
String encoded = encoder.drain();
Base64.Decoder decoder = new Base64.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;
}
}
}
System.out.println(mesg);
if (printData)
{
System.out.println("Decoded: " + new String(raw));
System.out.println("Encoded: " + encoded);
System.out.println("Decoded: " + new String(check));
}
/*
if (args.length==0)
{
System.err.println("Usage: java util.Base64 filename");
System.exit(1);
}
File f = new File( args[0] );
URL url = FileUtils.toURL(f);
InputStream in = url.openStream();
Base64.Encoder enc = new Base64.Encoder(1024 * 4 / 3 + 2*1024/76);
byte data [] = new byte[1024];
while ( true )
{
int len = in.read( data );
if ( len == -1 )
break;
enc.encode( data, 0, len );
System.out.print( enc.drain() );
}
System.out.print( enc.flush() );
*/
}
}