io.netty.handler.codec.xml.XmlFrameDecoder Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.codec.xml;
import static io.netty.util.internal.ObjectUtil.checkPositive;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.CorruptedFrameException;
import io.netty.handler.codec.TooLongFrameException;
import java.util.List;
/**
* A frame decoder for single separate XML based message streams.
*
* A couple examples will better help illustrate
* what this decoder actually does.
*
* Given an input array of bytes split over 3 frames like this:
*
* +-----+-----+-----------+
* | <an | Xml | Element/> |
* +-----+-----+-----------+
*
*
* this decoder would output a single frame:
*
*
* +-----------------+
* | <anXmlElement/> |
* +-----------------+
*
*
* Given an input array of bytes split over 5 frames like this:
*
* +-----+-----+-----------+-----+----------------------------------+
* | <an | Xml | Element/> | <ro | ot><child>content</child></root> |
* +-----+-----+-----------+-----+----------------------------------+
*
*
* this decoder would output two frames:
*
*
* +-----------------+-------------------------------------+
* | <anXmlElement/> | <root><child>content</child></root> |
* +-----------------+-------------------------------------+
*
*
*
* The byte stream is expected to be in UTF-8 character encoding or ASCII. The current implementation
* uses direct {@code byte} to {@code char} cast and then compares that {@code char} to a few low range
* ASCII characters like {@code '<'}, {@code '>'} or {@code '/'}. UTF-8 is not using low range [0..0x7F]
* byte values for multibyte codepoint representations therefore fully supported by this implementation.
*
* Please note that this decoder is not suitable for
* xml streaming protocols such as
* XMPP,
* where an initial xml element opens the stream and only
* gets closed at the end of the session, although this class
* could probably allow for such type of message flow with
* minor modifications.
*/
public class XmlFrameDecoder extends ByteToMessageDecoder {
private final int maxFrameLength;
public XmlFrameDecoder(int maxFrameLength) {
this.maxFrameLength = checkPositive(maxFrameLength, "maxFrameLength");
}
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf in, List