//
// ========================================================================
// Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under
// the terms of the Eclipse Public License 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0
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// This Source Code may also be made available under the following
// Secondary Licenses when the conditions for such availability set
// forth in the Eclipse Public License, v. 2.0 are satisfied:
// the Apache License v2.0 which is available at
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//

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.

/** * Stateful parser for lines of UTF8 formatted text, looking for <code>"\n"</code> as a line termination character. * <p> * 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.
Params:
  • buf – the buffer to parse (could be an incomplete buffer)
Throws:
Returns:the line of UTF8 parsed text, or null if no line end termination has been reached within the remaining bytes of the provided ByteBuffer. (In the case of a null, a subsequent ByteBuffer with a line end termination should be provided)
/** * 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); return false; case END: if (b == '\n') { // we've reached the end state = State.START; return true; } return false; default: throw new IllegalStateException(); } } }