com.jcabi.xml.StrictXML Maven / Gradle / Ivy
Show all versions of jcabi-xml Show documentation
/**
* Copyright (c) 2012-2017, jcabi.com
* 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. 3) Neither the name of the jcabi.com nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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 HOLDER 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.
*/
package com.jcabi.xml;
import com.jcabi.log.Logger;
import java.io.IOException;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;
import lombok.EqualsAndHashCode;
import org.w3c.dom.Node;
import org.w3c.dom.ls.LSResourceResolver;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
/**
* Strict {@link XML} that fails if encapsulated XML document
* doesn't validate against externally provided XSD schema or internally
* specified schema locations.
*
* Objects of this class are immutable and thread-safe.
*
* @author Yegor Bugayenko ([email protected])
* @version $Id: d44068ef3992d38ac5a770fd580546115a49487c $
* @since 0.7
* @checkstyle AbbreviationAsWordInNameCheck (5 lines)
*/
@EqualsAndHashCode(of = "origin")
public final class StrictXML implements XML {
/**
* Original XML document.
*/
private final transient XML origin;
/**
* Public ctor.
* @param xml XML document
*/
public StrictXML(final XML xml) {
this(xml, new ClasspathResolver());
}
/**
* Public ctor.
* @param xml XML document
* @param resolver Custom resolver
* @since 0.19
*/
public StrictXML(final XML xml, final LSResourceResolver resolver) {
this(xml, StrictXML.newValidator(resolver));
}
/**
* Public ctor.
* @param xml XML document
* @param val Custom validator
*/
public StrictXML(final XML xml, final Validator val) {
this(xml, StrictXML.validate(xml, val));
}
/**
* Public ctor.
* @param xml XML document
* @param schema XSD schema
*/
public StrictXML(final XML xml, final XSD schema) {
this(xml, schema.validate(new DOMSource(xml.node())));
}
/**
* Private ctor.
* @param xml XML Document
* @param errors XML Document errors
*/
@SuppressWarnings("PMD.ConstructorOnlyInitializesOrCallOtherConstructors")
private StrictXML(final XML xml,
final Collection errors) {
if (!errors.isEmpty()) {
Logger.warn(
StrictXML.class,
"%d XML validation error(s):\n %s\n%s",
errors.size(),
StrictXML.join(StrictXML.print(errors), "\n "),
xml
);
throw new IllegalArgumentException(
String.format(
"%d error(s) in XML document: %s",
errors.size(),
StrictXML.join(StrictXML.print(errors), ";")
)
);
}
this.origin = xml;
}
@Override
public String toString() {
return this.origin.toString();
}
@Override
public List xpath(final String query) {
return this.origin.xpath(query);
}
@Override
public List nodes(final String query) {
return this.origin.nodes(query);
}
@Override
public XML registerNs(final String prefix, final Object uri) {
return this.origin.registerNs(prefix, uri);
}
@Override
public XML merge(final NamespaceContext context) {
return this.origin.merge(context);
}
@Override
public Node node() {
return this.origin.node();
}
/**
* Convert errors to lines.
* @param errors The errors
* @return List of messages to print
*/
private static Iterable print(
final Collection errors) {
final Collection lines = new ArrayList<>(errors.size());
for (final SAXParseException error : errors) {
lines.add(
String.format(
"%d:%d: %s",
error.getLineNumber(),
error.getColumnNumber(),
error.getMessage()
)
);
}
return lines;
}
/**
* Joins many objects' string representations with the given separator
* string. The separator will not be appended to the beginning or the end.
* @param iterable Iterable of objects.
* @param sep Separator string.
* @return Joined string.
*/
private static String join(final Iterable iterable, final String sep) {
final Iterator iterator = iterable.iterator();
final Object first = iterator.next();
// @checkstyle MagicNumber (1 line)
final StringBuilder buf = new StringBuilder(256);
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
buf.append(sep);
final Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* Validate XML without external schema.
* @param xml XML Document
* @param validator XML Validator
* @return List of validation errors
*/
private static Collection validate(
final XML xml,
final Validator validator) {
final Collection errors =
new CopyOnWriteArrayList<>();
final int max = 3;
try {
validator.setErrorHandler(
new XSDDocument.ValidationHandler(errors)
);
final DOMSource dom = new DOMSource(xml.node());
for (int retry = 1; retry <= max; ++retry) {
try {
validator.validate(dom);
break;
} catch (final SocketException ex) {
Logger.error(
StrictXML.class,
"Try #%d of %d failed: %s: %s",
retry,
max,
ex.getClass().getName(),
ex.getMessage()
);
if (retry == max) {
throw new IllegalStateException(ex);
}
}
}
} catch (final SAXException | IOException ex) {
throw new IllegalStateException(ex);
}
return errors;
}
/**
* Creates a new validator.
* @param resolver The resolver for resources
* @return A new validator
*/
private static Validator newValidator(final LSResourceResolver resolver) {
try {
final Validator validator = SchemaFactory
.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI)
.newSchema()
.newValidator();
validator.setResourceResolver(resolver);
return validator;
} catch (final SAXException ex) {
throw new IllegalStateException(ex);
}
}
}