org.teiid.util.XMLInputStream Maven / Gradle / Ivy
/*
* Copyright Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags and
* the COPYRIGHT.txt file distributed with this work.
*
* Licensed 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 org.teiid.util;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;
import javax.xml.transform.stax.StAXSource;
import org.teiid.core.types.Streamable;
import org.teiid.core.types.XMLType;
import org.teiid.core.util.AccessibleByteArrayOutputStream;
/**
* Provides an {@link InputStream} adapter for StAX
*/
public class XMLInputStream extends InputStream {
private static final int BUFFER_SIZE = 1<<13;
private int pos = 0;
private AccessibleByteArrayOutputStream baos = new AccessibleByteArrayOutputStream(BUFFER_SIZE);
private XMLEventReader reader;
private XMLEventWriter writer;
/**
* Return a UTF-8 {@link InputStream} of the XML
* @param source
* @param outFactory
* @throws XMLStreamException
*/
public XMLInputStream(StAXSource source, XMLOutputFactory outFactory) throws XMLStreamException {
this(source, outFactory, Streamable.ENCODING);
}
public XMLInputStream(StAXSource source, XMLOutputFactory outFactory, String encoding) throws XMLStreamException {
reader = source.getXMLEventReader();
if (reader == null) {
this.reader = XMLType.getXmlInputFactory().createXMLEventReader(source.getXMLStreamReader());
}
this.writer = outFactory.createXMLEventWriter(baos, encoding);
}
@Override
public int read() throws IOException {
while (pos >= baos.getCount()) {
if (!reader.hasNext()) {
return -1;
}
if (baos.getCount() > BUFFER_SIZE) {
baos.setCount(0);
pos = 0;
}
try {
XMLEvent event = reader.nextEvent();
writer.add(event);
writer.flush();
} catch (XMLStreamException e) {
throw new IOException(e);
}
}
return 0xff & baos.getBuffer()[pos++];
}
@Override
public void close() throws IOException {
try {
reader.close();
} catch (XMLStreamException e) {
throw new IOException(e);
}
}
}