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The coolest XML library for Java around. Define typesafe views (projections) to xml. Use XPath to read and write XML. Bind XML to Java collections. Requires at least Java6, supports Java8 features and has no further runtime dependencies.
/**
* Copyright 2012 Sven Ewald
*
* 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.xmlbeam.config;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Document;
import org.xmlbeam.XBProjector;
import org.xmlbeam.util.intern.DOMHelper;
/**
* Default configuration for {@link XBProjector} which uses Java default factories to create
* {@link Transformer} {@link DocumentBuilder} and {@link XPath}. You may want to inherit from this
* class to change this behavior.
*
* @author Sven Ewald
*/
@SuppressWarnings("serial")
public class DefaultXMLFactoriesConfig implements XMLFactoriesConfig {
/**
* This configuration can use one of three different ways to configure namespace handling.
* Namespaces may be ignored (NIHILISTIC), handled user defined prefix mappings
* (AGNOSTIC) or mapped automatically to the document prefixes (HEDONISTIC).
*/
public static enum NamespacePhilosophy {
/**
* There is no such thing as a namespace. Only elements and attributes without a namespace
* will be visible to projections. Using this option prevents getting exceptions when an
* XPath expression tries to select a non defined namespace. (You can't get errors if you
* deny the existence of errors.) DocumentBuilders are created with namespace awareness set
* to false.
*/
NIHILISTIC,
/**
* Maybe there are namespaces. Maybe not. You have to decide for yourself. Neither the xml
* parser, nor the XPath instances bill be modified by this confiruration. Using this option
* will require you to subclass this configuration and specify namespace handling yourself.
* This way allowes you to control prefix to namespace mapping for the XPath expressions.
* The namespace awareness flag of created DocumentBuilders won't be touched.
*/
AGNOSTIC,
/**
* Fun without pain. This is the default option in this configuration. If namespaces are
* defined in the document, the definition will be applied to your XPath expressions. Thus
* you may just use existing namespaces without bothering about prefix mapping.
* DocumentBuilders are created with namespace awareness set to false.
*/
HEDONISTIC
}
private static final String NON_EXISTING_URL = "http://xmlbeam.org/nonexisting_namespace";
private NamespacePhilosophy namespacePhilosophy = NamespacePhilosophy.HEDONISTIC;
private boolean isPrettyPrinting = true;
private boolean isOmitXMLDeclaration = true;
/**
* Empty default constructor, a Configuration has no state.
*/
public DefaultXMLFactoriesConfig() {
}
/**
* {@inheritDoc}
*/
@Override
public DocumentBuilder createDocumentBuilder() {
try {
DocumentBuilder documentBuilder = createDocumentBuilderFactory().newDocumentBuilder();
return documentBuilder;
} catch (ParserConfigurationException e) {
throw new RuntimeException(e);
}
}
/**
* {@inheritDoc}
*/
@Override
public DocumentBuilderFactory createDocumentBuilderFactory() {
DocumentBuilderFactory instance = DocumentBuilderFactory.newInstance();
if (!NamespacePhilosophy.AGNOSTIC.equals(namespacePhilosophy)) {
instance.setNamespaceAware(NamespacePhilosophy.HEDONISTIC.equals(namespacePhilosophy));
}
return instance;
}
/**
* {@inheritDoc}
*/
@Override
public Transformer createTransformer(Document... document) {
try {
Transformer transformer = createTransformerFactory().newTransformer();
if (isPrettyPrinting()) {
// Enable some pretty printing of the resulting xml.
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
}
if (isOmitXMLDeclaration()) {
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
}
return transformer;
} catch (TransformerConfigurationException e) {
throw new RuntimeException(e);
}
}
/**
* {@inheritDoc}
*/
@Override
public TransformerFactory createTransformerFactory() {
return TransformerFactory.newInstance();
}
/**
* {@inheritDoc}
*/
@Override
public XPath createXPath(final Document... document) {
final XPath xPath = createXPathFactory().newXPath();
if ((document == null) || (document.length == 0) || (!NamespacePhilosophy.HEDONISTIC.equals(namespacePhilosophy))) {
return xPath;
}
// For hedonistic name space philosophy we aspire a reasonable name space mapping.
final Map nameSpaceMapping = DOMHelper.getNamespaceMapping(document[0]);
final NamespaceContext ctx = new NamespaceContext() {
@Override
public String getNamespaceURI(String prefix) {
if (prefix == null) {
throw new IllegalArgumentException("null not allowed as prefix");
}
if (nameSpaceMapping.containsKey(prefix)) {
return nameSpaceMapping.get(prefix);
}
// Default is a global unique string uri to prevent xpath expression exeptions on
// nonexisting ns.
return NON_EXISTING_URL;
}
@Override
public String getPrefix(String uri) {
for (Entry e : nameSpaceMapping.entrySet()) {
if (e.getValue().equals(uri)) {
return e.getKey();
}
}
return null;
}
@Override
public Iterator getPrefixes(String val) {
return nameSpaceMapping.keySet().iterator();
}
};
xPath.setNamespaceContext(ctx);
return xPath;
}
/**
* {@inheritDoc}
*/
@Override
public XPathFactory createXPathFactory() {
return XPathFactory.newInstance();
}
/**
* @return the namespacePhilosophy
*/
public NamespacePhilosophy getNamespacePhilosophy() {
return namespacePhilosophy;
}
/**
* Getter for pretty printing option.
* @return true if output will be formatted
*/
public boolean isPrettyPrinting() {
return isPrettyPrinting;
}
/**
* @param namespacePhilosophy
* @return this for convenience
*/
public XMLFactoriesConfig setNamespacePhilosophy(NamespacePhilosophy namespacePhilosophy) {
this.namespacePhilosophy = namespacePhilosophy;
return this;
}
/**
* Setter for pretty printing option
* @param on (true == output will be formatted)
* @return this for convenience
*/
public DefaultXMLFactoriesConfig setPrettyPrinting(boolean on) {
this.isPrettyPrinting = on;
return this;
}
/**
* @return the isOmitXMLDeclaration
*/
public boolean isOmitXMLDeclaration() {
return isOmitXMLDeclaration;
}
/**
* @param isOmitXMLDeclaration the isOmitXMLDeclaration to set
* @return this for convenience
*/
public DefaultXMLFactoriesConfig setOmitXMLDeclaration(boolean isOmitXMLDeclaration) {
this.isOmitXMLDeclaration = isOmitXMLDeclaration;
return this;
}
}