biweekly.io.xml.XCalWriter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of biweekly Show documentation
Show all versions of biweekly Show documentation
An iCalendar parser/writer library written in Java.
package biweekly.io.xml;
import static biweekly.io.xml.XCalNamespaceContext.XCAL_NS;
import static biweekly.io.xml.XCalQNames.COMPONENTS;
import static biweekly.io.xml.XCalQNames.ICALENDAR;
import static biweekly.io.xml.XCalQNames.PARAMETERS;
import static biweekly.io.xml.XCalQNames.PROPERTIES;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.xml.namespace.QName;
import javax.xml.transform.Result;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import biweekly.ICalDataType;
import biweekly.ICalendar;
import biweekly.component.ICalComponent;
import biweekly.component.VTimezone;
import biweekly.io.SkipMeException;
import biweekly.io.scribe.component.ICalComponentScribe;
import biweekly.io.scribe.property.ICalPropertyScribe;
import biweekly.parameter.ICalParameters;
import biweekly.property.ICalProperty;
import biweekly.property.Version;
import biweekly.property.Xml;
import biweekly.util.Utf8Writer;
import biweekly.util.XmlUtils;
/*
Copyright (c) 2013-2021, Michael Angstadt
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of the FreeBSD Project.
*/
/**
*
* Writes xCards (XML-encoded iCalendar objects) in a streaming fashion.
*
*
* Example:
*
*
*
* ICalendar ical1 = ...
* ICalendar ical2 = ...
* File file = new File("icals.xml");
* XCalWriter writer = null;
* try {
* writer = new XCalWriter(file);
* writer.write(ical1);
* writer.write(ical2);
* } finally {
* if (writer != null) writer.close();
* }
*
* @author Michael Angstadt
* @see RFC 6351
*/
public class XCalWriter extends XCalWriterBase {
//How to use SAX to write XML: http://stackoverflow.com/q/4898590
private final Document DOC = XmlUtils.createDocument();
private final Writer writer;
private final TransformerHandler handler;
private final boolean icalendarElementExists;
private boolean started = false;
/**
* @param out the output stream to write to (UTF-8 encoding will be used)
*/
public XCalWriter(OutputStream out) {
this(out, (Integer) null);
}
/**
* @param out the output stream to write to (UTF-8 encoding will be used)
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
*/
public XCalWriter(OutputStream out, Integer indent) {
this(out, indent, null);
}
/**
* @param out the output stream to write to (UTF-8 encoding will be used)
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
* @param xmlVersion the XML version to use (defaults to "1.0") (Note: Many
* JDKs only support 1.0 natively. For XML 1.1 support, add a JAXP library
* like xalan to your project)
*/
public XCalWriter(OutputStream out, Integer indent, String xmlVersion) {
this(new Utf8Writer(out), indent, xmlVersion);
}
/**
* @param out the output stream to write to (UTF-8 encoding will be used)
* @param outputProperties properties to assign to the JAXP transformer (see
* {@link Transformer#setOutputProperties(Properties)})
*/
public XCalWriter(OutputStream out, Map outputProperties) {
this(new Utf8Writer(out), outputProperties);
}
/**
* @param file the file to write to (UTF-8 encoding will be used)
* @throws IOException if there's a problem opening the file
*/
public XCalWriter(File file) throws IOException {
this(file, (Integer) null);
}
/**
* @param file the file to write to (UTF-8 encoding will be used)
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
* @throws IOException if there's a problem opening the file
*/
public XCalWriter(File file, Integer indent) throws IOException {
this(file, indent, null);
}
/**
* @param file the file to write to (UTF-8 encoding will be used)
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
* @param xmlVersion the XML version to use (defaults to "1.0") (Note: Many
* JDKs only support 1.0 natively. For XML 1.1 support, add a JAXP library
* like xalan to your project)
* @throws IOException if there's a problem opening the file
*/
public XCalWriter(File file, Integer indent, String xmlVersion) throws IOException {
this(new Utf8Writer(file), indent, xmlVersion);
}
/**
* @param file the file to write to (UTF-8 encoding will be used)
* @param outputProperties properties to assign to the JAXP transformer (see
* {@link Transformer#setOutputProperties(Properties)})
* @throws IOException if there's a problem opening the file
*/
public XCalWriter(File file, Map outputProperties) throws IOException {
this(new Utf8Writer(file), outputProperties);
}
/**
* @param writer the writer to write to
*/
public XCalWriter(Writer writer) {
this(writer, (Integer) null);
}
/**
* @param writer the writer to write to
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
*/
public XCalWriter(Writer writer, Integer indent) {
this(writer, indent, null);
}
/**
* @param writer the writer to write to
* @param indent the number of indent spaces to use for pretty-printing or
* "null" to disable pretty-printing (disabled by default)
* @param xmlVersion the XML version to use (defaults to "1.0") (Note: Many
* JDKs only support 1.0 natively. For XML 1.1 support, add a JAXP library
* like xalan to your project)
*/
public XCalWriter(Writer writer, Integer indent, String xmlVersion) {
this(writer, new XCalOutputProperties(indent, xmlVersion));
}
/**
* @param writer the writer to write to
* @param outputProperties properties to assign to the JAXP transformer (see
* {@link Transformer#setOutputProperties(Properties)})
*/
public XCalWriter(Writer writer, Map outputProperties) {
this(writer, null, outputProperties);
}
/**
* @param parent the DOM node to add child elements to
*/
public XCalWriter(Node parent) {
this(null, parent, new HashMap());
}
private XCalWriter(Writer writer, Node parent, Map outputProperties) {
this.writer = writer;
if (parent instanceof Document) {
Node root = parent.getFirstChild();
if (root != null) {
parent = root;
}
}
this.icalendarElementExists = isICalendarElement(parent);
try {
SAXTransformerFactory factory = (SAXTransformerFactory) TransformerFactory.newInstance();
handler = factory.newTransformerHandler();
} catch (TransformerConfigurationException e) {
throw new RuntimeException(e);
}
Transformer transformer = handler.getTransformer();
/*
* Using Transformer#setOutputProperties(Properties) doesn't work for
* some reason for setting the number of indentation spaces.
*/
for (Map.Entry entry : outputProperties.entrySet()) {
String key = entry.getKey();
String value = entry.getValue();
transformer.setOutputProperty(key, value);
}
Result result = (writer == null) ? new DOMResult(parent) : new StreamResult(writer);
handler.setResult(result);
}
private boolean isICalendarElement(Node node) {
if (node == null) {
return false;
}
if (!(node instanceof Element)) {
return false;
}
return XmlUtils.hasQName(node, ICALENDAR);
}
@Override
protected void _write(ICalendar ical) throws IOException {
try {
if (!started) {
handler.startDocument();
if (!icalendarElementExists) {
//don't output a element if the parent is a element
start(ICALENDAR);
}
started = true;
}
write((ICalComponent) ical);
} catch (SAXException e) {
throw new IOException(e);
}
}
@SuppressWarnings({ "rawtypes", "unchecked" })
private void write(ICalComponent component) throws SAXException {
ICalComponentScribe scribe = index.getComponentScribe(component);
String name = scribe.getComponentName().toLowerCase();
start(name);
List properties = scribe.getProperties(component);
if (component instanceof ICalendar && component.getProperty(Version.class) == null) {
properties.add(0, new Version(targetVersion));
}
if (!properties.isEmpty()) {
start(PROPERTIES);
for (Object propertyObj : properties) {
context.setParent(component); //set parent here incase a scribe resets the parent
ICalProperty property = (ICalProperty) propertyObj;
write(property);
}
end(PROPERTIES);
}
List subComponents = scribe.getComponents(component);
if (component instanceof ICalendar) {
//add the VTIMEZONE components that were auto-generated by TimezoneOptions
Collection tzs = getTimezoneComponents();
for (VTimezone tz : tzs) {
if (!subComponents.contains(tz)) {
subComponents.add(0, tz);
}
}
}
if (!subComponents.isEmpty()) {
start(COMPONENTS);
for (Object subComponentObj : subComponents) {
ICalComponent subComponent = (ICalComponent) subComponentObj;
write(subComponent);
}
end(COMPONENTS);
}
end(name);
}
@SuppressWarnings({ "rawtypes", "unchecked" })
private void write(ICalProperty property) throws SAXException {
ICalPropertyScribe scribe = index.getPropertyScribe(property);
ICalParameters parameters = scribe.prepareParameters(property, context);
//get the property element to write
Element propertyElement;
if (property instanceof Xml) {
Xml xml = (Xml) property;
Document value = xml.getValue();
if (value == null) {
return;
}
propertyElement = value.getDocumentElement();
} else {
QName qname = scribe.getQName();
propertyElement = DOC.createElementNS(qname.getNamespaceURI(), qname.getLocalPart());
try {
scribe.writeXml(property, propertyElement, context);
} catch (SkipMeException e) {
return;
}
}
start(propertyElement);
write(parameters);
write(propertyElement);
end(propertyElement);
}
private void write(Element propertyElement) throws SAXException {
NodeList children = propertyElement.getChildNodes();
for (int i = 0; i < children.getLength(); i++) {
Node child = children.item(i);
if (child instanceof Element) {
Element element = (Element) child;
if (element.hasChildNodes()) {
start(element);
write(element);
end(element);
} else {
childless(element);
}
continue;
}
if (child instanceof Text) {
Text text = (Text) child;
text(text.getTextContent());
continue;
}
}
}
private void write(ICalParameters parameters) throws SAXException {
if (parameters.isEmpty()) {
return;
}
start(PARAMETERS);
for (Map.Entry> parameter : parameters) {
String parameterName = parameter.getKey().toLowerCase();
start(parameterName);
for (String parameterValue : parameter.getValue()) {
ICalDataType dataType = parameterDataTypes.get(parameterName);
String dataTypeElementName = (dataType == null) ? "unknown" : dataType.getName().toLowerCase();
start(dataTypeElementName);
text(parameterValue);
end(dataTypeElementName);
}
end(parameterName);
}
end(PARAMETERS);
}
/**
* Makes an childless element appear as {@code element if the parent is a element
start(ICALENDAR);
}
}
if (!icalendarElementExists) {
end(ICALENDAR);
}
handler.endDocument();
} catch (SAXException e) {
throw new IOException(e);
}
if (writer != null) {
writer.close();
}
}
}