com.msopentech.odatajclient.testservice.utils.XMLEventReaderWrapper.java Source code

Introduction

Here is the source code for com.msopentech.odatajclient.testservice.utils.XMLEventReaderWrapper.java

Source

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 com.msopentech.odatajclient.testservice.utils;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;
import org.apache.commons.io.IOUtils;

public class XMLEventReaderWrapper implements XMLEventReader {

    public final static String CONTENT = "CONTENT_TAG";

    public final static String CONTENT_STAG = "<" + CONTENT + ">";

    public final static String CONTENT_ETAG = "</" + CONTENT + ">";

    private final XMLEventReader wrapped;

    private XMLEvent nextGivenEvent = null;

    public XMLEventReaderWrapper(final InputStream stream) throws Exception {
        final XMLInputFactory factory = XMLInputFactory.newInstance();
        factory.setProperty(XMLInputFactory.IS_VALIDATING, false);
        factory.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, false);

        this.wrapped = factory.createXMLEventReader(new ByteArrayInputStream(
                (XMLEventReaderWrapper.CONTENT_STAG + IOUtils.toString(stream) + XMLEventReaderWrapper.CONTENT_ETAG)
                        .getBytes()));

        init(wrapped);
    }

    public XMLEventReaderWrapper(final XMLEventReader wrapped) {
        this.wrapped = wrapped;
        init(wrapped);
    }

    private void init(final XMLEventReader wrapped) {

        try {
            this.nextGivenEvent = this.wrapped.nextEvent();

            if (this.nextGivenEvent.isStartDocument()) {
                this.nextGivenEvent = this.wrapped.nextEvent(); // discard start document    
            }

            if (this.nextGivenEvent.isStartElement()
                    && CONTENT.equals(this.nextGivenEvent.asStartElement().getName().getLocalPart())) {
                this.nextGivenEvent = this.wrapped.nextEvent(); // discard content start tag
            }

        } catch (Exception ignore) {
            // ignore
        }
    }

    @Override
    public XMLEvent nextEvent() throws XMLStreamException {
        final XMLEvent event = nextGivenEvent;

        if (!isValidEvent(event)) {
            throw new IllegalStateException("No event found");
        }

        nextGivenEvent = wrapped.hasNext() ? wrapped.nextEvent() : null;

        return event;
    }

    @Override
    public boolean hasNext() {
        return isValidEvent(nextGivenEvent);
    }

    @Override
    public XMLEvent peek() throws XMLStreamException {
        return wrapped.peek();
    }

    @Override
    public String getElementText() throws XMLStreamException {
        return wrapped.getElementText();
    }

    @Override
    public XMLEvent nextTag() throws XMLStreamException {
        XMLEvent tagEvent = wrapped.nextTag();
        if (isValidEvent(tagEvent)) {
            return tagEvent;
        } else {
            return null;
        }
    }

    @Override
    public Object getProperty(final String string) throws IllegalArgumentException {
        return wrapped.getProperty(string);
    }

    @Override
    public void close() throws XMLStreamException {
        wrapped.close();
    }

    @Override
    public Object next() {
        return wrapped.next();
    }

    @Override
    public void remove() {
        wrapped.remove();
    }

    private boolean isValidEvent(final XMLEvent event) {
        // discard content end element tag ...
        return event != null
                && (!event.isEndElement() || !CONTENT.equals(event.asEndElement().getName().getLocalPart()));
    }
}