Java tutorial
/* * eXist EXPath * Copyright (C) 2011 Adam Retter <adam@existsolutions.com> * www.existsolutions.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id$ */ package org.expath.tools.model.exist; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.Writer; import java.nio.charset.StandardCharsets; import java.util.Properties; import javax.xml.XMLConstants; import javax.xml.namespace.QName; import javax.xml.transform.OutputKeys; import org.apache.commons.io.output.CloseShieldOutputStream; import org.exist.storage.serializers.Serializer; import org.exist.util.serializer.XQuerySerializer; import org.exist.xquery.XPathException; import org.exist.xquery.XQueryContext; import org.exist.xquery.value.Item; import org.exist.xquery.value.SequenceIterator; import org.expath.tools.ToolsException; import org.expath.tools.model.Sequence; import org.expath.tools.serial.SerialParameters; import org.xml.sax.SAXException; /** * @author Adam Retter <adam@existsolutions.com> */ public class EXistSequence implements Sequence { private final org.exist.xquery.value.Sequence sequence; private SequenceIterator sequenceIterator = SequenceIterator.EMPTY_ITERATOR; private final XQueryContext context; public EXistSequence(final org.exist.xquery.value.Sequence sequence, final XQueryContext context) throws XPathException { this.sequence = sequence; if (sequence != null) { this.sequenceIterator = sequence.iterate(); } this.context = context; } @Override public boolean isEmpty() throws ToolsException { return sequence.isEmpty(); } @Override public Sequence next() throws ToolsException { try { final Item item = sequenceIterator.nextItem(); final org.exist.xquery.value.Sequence singleton = (org.exist.xquery.value.Sequence) item; return new EXistSequence(singleton, context); } catch (final XPathException xpe) { throw new ToolsException(xpe.getMessage(), xpe); } } @Override public void serialize(final OutputStream out, final SerialParameters params) throws ToolsException { final Properties props = params == null ? null : makeOutputProperties(params); props.setProperty(Serializer.GENERATE_DOC_EVENTS, "false"); final String encoding = props.getProperty(OutputKeys.ENCODING, StandardCharsets.UTF_8.name()); try (final Writer writer = new OutputStreamWriter(new CloseShieldOutputStream(out), encoding)) { final XQuerySerializer xqSerializer = new XQuerySerializer(context.getBroker(), props, writer); xqSerializer.serialize(sequence); } catch (final SAXException | IOException | XPathException e) { throw new ToolsException("A problem occurred while serializing the node set: " + e.getMessage(), e); } } /** * Borrowed from {@link org.expath.tools.saxon.model.SaxonSequence} */ private Properties makeOutputProperties(final SerialParameters params) throws ToolsException { final Properties props = new Properties(); setOutputKey(props, OutputKeys.METHOD, params.getMethod()); setOutputKey(props, OutputKeys.MEDIA_TYPE, params.getMediaType()); setOutputKey(props, OutputKeys.ENCODING, params.getEncoding()); setOutputKey(props, OutputKeys.CDATA_SECTION_ELEMENTS, params.getCdataSectionElements()); setOutputKey(props, OutputKeys.DOCTYPE_PUBLIC, params.getDoctypePublic()); setOutputKey(props, OutputKeys.DOCTYPE_SYSTEM, params.getDoctypeSystem()); setOutputKey(props, OutputKeys.INDENT, params.getIndent()); setOutputKey(props, OutputKeys.OMIT_XML_DECLARATION, params.getOmitXmlDeclaration()); setOutputKey(props, OutputKeys.STANDALONE, params.getStandalone()); setOutputKey(props, OutputKeys.VERSION, params.getVersion()); return props; } private void setOutputKey(Properties props, String name, String value) throws ToolsException { if (value != null) { props.setProperty(name, value); } } private void setOutputKey(Properties props, String name, Boolean value) throws ToolsException { if (value != null) { props.setProperty(name, value ? "yes" : "no"); } } private void setOutputKey(Properties props, String name, SerialParameters.Standalone value) throws ToolsException { if (value != null) { switch (value) { case YES: props.setProperty(name, "yes"); break; case NO: props.setProperty(name, "no"); break; case OMIT: props.setProperty(name, "omit"); break; default: throw new ToolsException("Invalid Standalone value: " + value); } } } private void setOutputKey(Properties props, String name, QName value) throws ToolsException { if (value != null) { if (value.getNamespaceURI() != null && !value.getNamespaceURI().equals(XMLConstants.NULL_NS_URI)) { throw new ToolsException( "A QName with a non-null namespace not supported as a serialization param: {" + value.getNamespaceURI() + "}" + value.getLocalPart()); } props.setProperty(name, value.getLocalPart()); } } private void setOutputKey(Properties props, String name, Iterable<QName> value) throws ToolsException { if (value != null) { StringBuilder buf = new StringBuilder(); for (QName qname : value) { if (qname.getNamespaceURI() != null) { throw new ToolsException( "A QName with a non-null namespace not supported as a serialization param: {" + qname.getNamespaceURI() + "}" + qname.getLocalPart()); } buf.append(qname.getLocalPart()); buf.append(" "); } props.setProperty(name, buf.toString()); } } }