org.openmdx.base.io.UTF8Writer Maven / Gradle / Ivy
/*
* ====================================================================
* Project: openMDX/Core, http://www.openmdx.org/
* Description: UTF8 Writer
* Owner: OMEX AG, Switzerland, http://www.omex.ch
* ====================================================================
*
* This software is published under the BSD license as listed below.
*
* Copyright (c) 2010, OMEX AG, Switzerland
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the openMDX team nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ------------------
*
* This product includes software developed by other organizations as
* listed in the NOTICE file.
*/
package org.openmdx.base.io;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
/**
* Write UTF-8 characters to an output stream without buffering
*
* The methods flush() and close()
* are not delegated on to the underlying stream on purpose!
*/
public class UTF8Writer extends Writer {
/**
* Constructor
*
* @param binaryStream
*/
public UTF8Writer(
OutputStream binaryStream
) {
this.binaryStream = binaryStream;
}
/**
* The delegate
*/
private OutputStream binaryStream;
/**
* Java represents chars that are not in the Basic Multilingual
* Plane (BMP) in UTF-16. This integer stores the first code unit
* for a code point encoded in two UTF-16 code units.
*/
private int pending = 0;
/**
* Non-buffering write
*/
@Override
public final void write(
int utf16
) throws IOException {
//
// Check in we are encoding at high and low surrogates
//
if (this.pending == 0) {
//
// Otherwise, encode char as defined in UTF-8
//
if (utf16 < 0x80) {
//
// 1 byte, 7 bits
//
this.binaryStream.write(utf16);
} else if (utf16 < 0x800) {
//
// 2 bytes, 11 bits
//
this.binaryStream.write(0xC0 | (utf16 >> 6)); // first 5
this.binaryStream.write(0x80 | (utf16 & 0x3F)); // second 6
} else if (utf16 <= '\uFFFF') {
char character = (char) utf16;
if (
!Character.isHighSurrogate(character) &&
!Character.isLowSurrogate(character)
) {
//
// 3 bytes, 16 bits
//
this.binaryStream.write(0xE0 | (utf16 >> 12)); // first 4
this.binaryStream.write(0x80 | ((utf16 >> 6) & 0x3F)); // second 6
this.binaryStream.write(0x80 | (utf16 & 0x3F)); // third 6
} else {
this.pending = utf16;
}
}
} else {
final int uc = (((pending & 0x3ff) << 10) | (utf16 & 0x3ff)) + 0x10000;
if (uc < 0 || uc >= 0x200000) throw new IOException(
"Atttempting to write invalid Unicode code point '" + uc + "'"
);
this.binaryStream.write(0xF0 | (uc >> 18));
this.binaryStream.write(0x80 | ((uc >> 12) & 0x3F));
this.binaryStream.write(0x80 | ((uc >> 6) & 0x3F));
this.binaryStream.write(0x80 | (uc & 0x3F));
pending = 0;
}
}
/**
* Non-buffering write
*/
@Override
public final void write(
char utf16[]
) throws IOException {
for (int i = 0; i < utf16.length; i++) {
write(utf16[i]);
}
}
/**
* Immediately delegating write
*/
@Override
public final void write(
char utf16[],
int offset,
int length
) throws IOException {
for (int i = 0; i < length; i++) {
write(utf16[offset + i]);
}
}
/**
* Non-buffering write
*/
@Override
public final void write(
String utf16
) throws IOException {
final int len = utf16.length();
for (int i = 0; i < len; i++) {
write(utf16.charAt(i));
}
}
/**
* Non-buffering write
*/
@Override
public final void write(
String str,
int off,
int len
) throws IOException {
for (int i = 0; i < len; i++) {
write(str.charAt(off + i));
}
}
/**
* Immediately delegating write
*/
/**
* Non-delegating flush
*/
@Override
public final void flush(
) throws IOException {
if (this.pending != 0) {
throw new IOException(
"Unable to flush an incomplete UNICODE code point"
);
}
}
/**
* Non-delegating close
*/
@Override
public final void close(
) throws IOException {
flush();
this.binaryStream = null;
}
}