/*
* Copyright 2005-2015 by BerryWorks Software, LLC. All rights reserved.
*
* This file is part of EDIReader. You may obtain a license for its use directly from
* BerryWorks Software, and you may also choose to use this software under the terms of the
* GPL version 3. Other products in the EDIReader software suite are available only by licensing
* with BerryWorks. Only those files bearing the GPL statement below are available under the GPL.
*
* EDIReader is free software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* EDIReader is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with EDIReader. If not,
* see <http://www.gnu.org/licenses/>.
*/
package com.berryworks.edireader.util.base64;
import java.io.IOException;
import java.io.InputStream;
import java.nio.CharBuffer;
/**
* Decodes a sequence of base-64 encoded bytes into an
* 8-bit byte sequence representing the original data.
*/
public abstract class AbstractDecoder extends AbstractEncoderDecoder {
private final DecoderFrontEnd frontEnd;
private final DecoderBackEnd backEnd;
private static final int BUFFER_SIZE = 1000;
public AbstractDecoder() {
frontEnd = new DecoderFrontEnd() {
@Override
protected void emit(byte value) {
backEnd.consume(value);
}
@Override
protected void endOfData() {
backEnd.endOfData();
}
};
final AbstractEncoderDecoder thisDecoder = this;
backEnd = new DecoderBackEnd() {
@Override
protected void emit(byte b) {
thisDecoder.emit(b);
}
};
}
@Override
public void consume(byte b) {
frontEnd.consume(b);
}
@Override
protected void endOfData() {
frontEnd.endOfData();
}
/**
* Reads base-64 encoded bytes from an input stream
* and directs their decoding.
*
* @param inputStream stream of chars to be decoded
* @throws IOException if an error occurs reading the inputStream
*/
public void decode(InputStream inputStream) throws IOException {
reset();
byte buffer[] = new byte[BUFFER_SIZE];
while (true) {
int n = inputStream.read(buffer);
if (n < 0) {
endOfData();
break;
} else if (n > 0)
for (int i = 0; i < n; i++)
consume(buffer[i]);
}
}
/**
* Directs the decoding of base-64 encoded bytes provided in an array.
*
* @param bytes to be decoded
*/
public void decode(byte[] bytes) {
reset();
for (byte aByte : bytes) consume(aByte);
endOfData();
}
public void decode(String s) {
CharBuffer charBuffer = CharBuffer.wrap(s);
decode(charset.encode(charBuffer).array());
}
@Override
protected void reset() {
frontEnd.reset();
backEnd.reset();
}
}