org.eclipse.jetty.util.Utf8LineParser Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2012 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.util;
import java.nio.ByteBuffer;
import org.eclipse.jetty.util.Utf8Appendable.NotUtf8Exception;
/**
* Stateful parser for lines of UTF8 formatted text, looking for "\n" as a line termination character.
*
* For use with new IO framework that is based on ByteBuffer parsing.
*/
public class Utf8LineParser
{
private enum State
{
START,
PARSE,
END;
}
private State state;
private Utf8StringBuilder utf;
public Utf8LineParser()
{
this.state = State.START;
}
/**
* Parse a ByteBuffer (could be a partial buffer), and return once a complete line of UTF8 parsed text has been reached.
*
* @param buf
* the buffer to parse (could be an incomplete buffer)
* @return the line of UTF8 parsed text, or null if no line end termination has been reached within the {@link ByteBuffer#remaining() remaining} bytes of
* the provided ByteBuffer. (In the case of a null, a subsequent ByteBuffer with a line end termination should be provided)
* @throws NotUtf8Exception
* if the input buffer has bytes that do not conform to UTF8 validation (validation performed by {@link Utf8StringBuilder}
*/
public String parse(ByteBuffer buf)
{
byte b;
while (buf.remaining() > 0)
{
b = buf.get();
if (parseByte(b))
{
state = State.START;
return utf.toString();
}
}
// have not reached end of line (yet)
return null;
}
private boolean parseByte(byte b)
{
switch (state)
{
case START:
utf = new Utf8StringBuilder();
state = State.PARSE;
return parseByte(b);
case PARSE:
// not waiting on more UTF sequence parts.
if (utf.isUtf8SequenceComplete() && ((b == '\r') || (b == '\n')))
{
state = State.END;
return parseByte(b);
}
utf.append(b);
break;
case END:
if (b == '\n')
{
// we've reached the end
state = State.START;
return true;
}
break;
}
return false;
}
}