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/*
* Copyright (c) 2011, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package org.jvnet.staxex;
import java.io.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
// for testing method
//import com.sun.xml.stream.writers.XMLStreamWriterImpl;
/**
* This class implements a BASE64 Encoder. It is implemented as
* a FilterOutputStream, so one can just wrap this class around
* any output stream and write bytes into this filter. The Encoding
* is done as the bytes are written out.
*
* @author John Mani
* @author Bill Shannon
* @author Martin Grebac
*/
public class Base64EncoderStream extends FilterOutputStream {
private byte[] buffer; // cache of bytes that are yet to be encoded
private int bufsize = 0; // size of the cache
private XMLStreamWriter outWriter;
public Base64EncoderStream(OutputStream out) {
super(out);
buffer = new byte[3];
}
/**
* Create a BASE64 encoder that encodes the specified input stream
* @param out
*/
public Base64EncoderStream(XMLStreamWriter outWriter, OutputStream out) {
super(out);
buffer = new byte[3];
this.outWriter = outWriter;
}
/**
* Encodes len bytes from the specified
* byte array starting at offset off to
* this output stream.
*
* @param b the data.
* @param off the start offset in the data.
* @param len the number of bytes to write.
* @exception IOException if an I/O error occurs.
*/
@Override
public void write(byte[] b, int off, int len) throws IOException {
for (int i = 0; i < len; i++)
write(b[off + i]);
}
/**
* Encodes b.length bytes to this output stream.
* @param b the data to be written.
* @exception IOException if an I/O error occurs.
*/
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
/**
* Encodes the specified byte to this output stream.
* @param c the byte.
* @exception IOException if an I/O error occurs.
*/
@Override
public void write(int c) throws IOException {
buffer[bufsize++] = (byte)c;
if (bufsize == 3) { // Encoding unit = 3 bytes
encode();
bufsize = 0;
}
}
/**
* Flushes this output stream and forces any buffered output bytes
* to be encoded out to the stream.
* @exception IOException if an I/O error occurs.
*/
@Override
public void flush() throws IOException {
if (bufsize > 0) { // If there's unencoded characters in the buffer ..
encode(); // .. encode them
bufsize = 0;
}
out.flush();
try {
outWriter.flush();
} catch (XMLStreamException ex) {
Logger.getLogger(Base64EncoderStream.class.getName()).log(Level.SEVERE, null, ex);
throw new IOException(ex);
}
}
/**
* Forces any buffered output bytes to be encoded out to the stream
* and closes this output stream
*/
@Override
public void close() throws IOException {
flush();
out.close();
}
/** This array maps the characters to their 6 bit values */
private final static char pem_array[] = {
'A','B','C','D','E','F','G','H', // 0
'I','J','K','L','M','N','O','P', // 1
'Q','R','S','T','U','V','W','X', // 2
'Y','Z','a','b','c','d','e','f', // 3
'g','h','i','j','k','l','m','n', // 4
'o','p','q','r','s','t','u','v', // 5
'w','x','y','z','0','1','2','3', // 6
'4','5','6','7','8','9','+','/' // 7
};
private void encode() throws IOException {
byte a, b, c;
char[] buf = new char[4];
if (bufsize == 1) {
a = buffer[0];
b = 0;
c = 0;
buf[0] = pem_array[(a >>> 2) & 0x3F];
buf[1] = pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)];
buf[2] = '='; // pad character
buf[3] = '='; // pad character
} else if (bufsize == 2) {
a = buffer[0];
b = buffer[1];
c = 0;
buf[0] = pem_array[(a >>> 2) & 0x3F];
buf[1] = pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)];
buf[2] = pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)];
buf[3] = '='; // pad character
} else {
a = buffer[0];
b = buffer[1];
c = buffer[2];
buf[0] = pem_array[(a >>> 2) & 0x3F];
buf[1] = pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)];
buf[2] = pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)];
buf[3] = pem_array[c & 0x3F];
}
try {
outWriter.writeCharacters(buf, 0, 4);
} catch (XMLStreamException ex) {
Logger.getLogger(Base64EncoderStream.class.getName()).log(Level.SEVERE, null, ex);
throw new IOException(ex);
}
}
// public static void main(String argv[]) throws Exception {
// FileInputStream infile = new FileInputStream(new File(argv[0]));
// StringWriter sw = new StringWriter();
// XMLStreamWriterImpl wi = new XMLStreamWriterImpl(sw, null);
// ByteArrayOutputStream baos = new ByteArrayOutputStream();
// Base64EncoderStream encoder = new Base64EncoderStream(wi, baos);
// int c;
//
// while ((c = infile.read()) != -1)
// encoder.write(c);
// encoder.close();
//
// System.out.println("SW: " + sw.toString());
// System.out.println("BAOS: " + baos.toString());
//
// }
}