org.apache.axiom.om.ds.AbstractPushOMDataSource Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* 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
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*/
package org.apache.axiom.om.ds;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
import org.apache.axiom.om.OMDataSource;
import org.apache.axiom.om.OMDataSourceExt;
import org.apache.axiom.om.OMOutputFormat;
import org.apache.axiom.om.OMSourcedElement;
import org.apache.axiom.om.util.StAXUtils;
/**
* Base class for {@link OMDataSourceExt} implementations that can easily serialize the content to
* an {@link XMLStreamWriter} but that are unable to produce the content as an
* {@link XMLStreamReader}.
*
* {@link OMSourcedElement} will handle {@link OMDataSource} implementations extending this class
* differently when it comes to expansion: instead of using {@link OMDataSource#getReader()} to
* expand the element, it will use {@link OMDataSource#serialize(XMLStreamWriter)} (with a special
* {@link XMLStreamWriter} that builds the descendants of the {@link OMSourcedElement}). This means
* that such an {@link OMSourcedElement} will be expanded instantly, and that deferred building of
* the descendants is not applicable.
*/
public abstract class AbstractPushOMDataSource extends AbstractOMDataSource {
@Override
public final boolean isDestructiveRead() {
return isDestructiveWrite();
}
@Override
public final XMLStreamReader getReader() throws XMLStreamException {
// Note: we don't actually expect this code to be called because OMSourcedElement should handle
// AbstractPushOMDataSource instances differently. Nevertheless the code is functionally correct
// (but not very good from a performance point of view, especially for XOP).
ByteArrayOutputStream bos = new ByteArrayOutputStream();
serialize(bos, new OMOutputFormat());
return StAXUtils.createXMLStreamReader(new ByteArrayInputStream(bos.toByteArray()));
}
}