alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (XmlDecoder.java)

This example Java source code file (XmlDecoder.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

asyncbytearrayfeeder, asyncxmlinputfactory, asyncxmlstreamreader, bytetomessagedecoder, inputfactoryimpl, override, util, xml_document_end, xml_input_factory, xmldecoder, xmldocumentend, xmlelementend, xmlelementstart, xmlnamespace, xmlstreamexception

The XmlDecoder.java Java example source code

/*
 * Copyright 2014 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:
 *
 *   http://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 com.fasterxml.aalto.AsyncByteArrayFeeder;
import com.fasterxml.aalto.AsyncXMLInputFactory;
import com.fasterxml.aalto.AsyncXMLStreamReader;
import com.fasterxml.aalto.stax.InputFactoryImpl;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import java.util.List;

/**
 * Async XML decoder based on <a href="https://github.com/FasterXML/aalto-xml">Aalto XML parser.
 *
 * Parses the incoming data into one of XML messages defined in this package.
 */

public class XmlDecoder extends ByteToMessageDecoder {

    private static final AsyncXMLInputFactory XML_INPUT_FACTORY = new InputFactoryImpl();
    private static final XmlDocumentEnd XML_DOCUMENT_END = XmlDocumentEnd.INSTANCE;

    private final AsyncXMLStreamReader streamReader = XML_INPUT_FACTORY.createAsyncForByteArray();
    private final AsyncByteArrayFeeder streamFeeder = (AsyncByteArrayFeeder) streamReader.getInputFeeder();

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        byte[] buffer = new byte[in.readableBytes()];
        in.readBytes(buffer);
        try {
            streamFeeder.feedInput(buffer, 0, buffer.length);
        } catch (XMLStreamException exception) {
            in.skipBytes(in.readableBytes());
            throw exception;
        }

        while (!streamFeeder.needMoreInput()) {
            int type = streamReader.next();
            switch (type) {
                case XMLStreamConstants.START_DOCUMENT:
                    out.add(new XmlDocumentStart(streamReader.getEncoding(), streamReader.getVersion(),
                            streamReader.isStandalone(), streamReader.getCharacterEncodingScheme()));
                    break;
                case XMLStreamConstants.END_DOCUMENT:
                    out.add(XML_DOCUMENT_END);
                    break;
                case XMLStreamConstants.START_ELEMENT:
                    XmlElementStart elementStart = new XmlElementStart(streamReader.getLocalName(),
                            streamReader.getName().getNamespaceURI(), streamReader.getPrefix());
                    for (int x = 0; x < streamReader.getAttributeCount(); x++) {
                        XmlAttribute attribute = new XmlAttribute(streamReader.getAttributeType(x),
                                streamReader.getAttributeLocalName(x), streamReader.getAttributePrefix(x),
                                streamReader.getAttributeNamespace(x), streamReader.getAttributeValue(x));
                        elementStart.attributes().add(attribute);
                    }
                    for (int x = 0; x < streamReader.getNamespaceCount(); x++) {
                        XmlNamespace namespace = new XmlNamespace(streamReader.getNamespacePrefix(x),
                                streamReader.getNamespaceURI(x));
                        elementStart.namespaces().add(namespace);
                    }
                    out.add(elementStart);
                    break;
                case XMLStreamConstants.END_ELEMENT:
                    XmlElementEnd elementEnd = new XmlElementEnd(streamReader.getLocalName(),
                            streamReader.getName().getNamespaceURI(), streamReader.getPrefix());
                    for (int x = 0; x < streamReader.getNamespaceCount(); x++) {
                        XmlNamespace namespace = new XmlNamespace(streamReader.getNamespacePrefix(x),
                                streamReader.getNamespaceURI(x));
                        elementEnd.namespaces().add(namespace);
                    }
                    out.add(elementEnd);
                    break;
                case XMLStreamConstants.PROCESSING_INSTRUCTION:
                    out.add(new XmlProcessingInstruction(streamReader.getPIData(), streamReader.getPITarget()));
                    break;
                case XMLStreamConstants.CHARACTERS:
                    out.add(new XmlCharacters(streamReader.getText()));
                    break;
                case XMLStreamConstants.COMMENT:
                    out.add(new XmlComment(streamReader.getText()));
                    break;
                case XMLStreamConstants.SPACE:
                    out.add(new XmlSpace(streamReader.getText()));
                    break;
                case XMLStreamConstants.ENTITY_REFERENCE:
                    out.add(new XmlEntityReference(streamReader.getLocalName(), streamReader.getText()));
                    break;
                case XMLStreamConstants.DTD:
                    out.add(new XmlDTD(streamReader.getText()));
                    break;
                case XMLStreamConstants.CDATA:
                    out.add(new XmlCdata(streamReader.getText()));
                    break;
            }
        }
    }

}

Other Java examples (source code examples)

Here is a short list of links related to this Java XmlDecoder.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.