/*
* JBoss, Home of Professional Open Source
* Copyright 2013, Red Hat, Inc. and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.hibernate.jpamodelgen.util.xml;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.tools.FileObject;
import javax.tools.StandardLocation;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import org.hibernate.jpamodelgen.Context;
import org.hibernate.jpamodelgen.util.Constants;
import org.hibernate.jpamodelgen.xml.jaxb.ObjectFactory;
import org.xml.sax.SAXException;
/**
* Provides common functionality used for XML parsing.
*
* @author Gunnar Morling
* @author Hardy Ferentschik
*/
public class XmlParserHelper {
/**
* Path separator used for resource loading
*/
private static final String RESOURCE_PATH_SEPARATOR = "/";
/**
* The expected number of XML schemas managed by this class. Used to set the
* initial cache size.
*/
private static final int NUMBER_OF_SCHEMAS = 4;
private static final XMLInputFactory XML_INPUT_FACTORY = XMLInputFactory.newInstance();
private static final ConcurrentMap<String, Schema> SCHEMA_CACHE = new ConcurrentHashMap<String, Schema>(
NUMBER_OF_SCHEMAS
);
private final Context context;
public XmlParserHelper(Context context) {
this.context = context;
}
/**
* Returns an input stream for the specified resource. First an attempt is made to load the resource
* via the {@code Filer} API and if that fails {@link Class#getResourceAsStream} is used.
*
* @param resource the resource to load
*
* @return an input stream for the specified resource or {@code null} in case resource cannot be loaded
*/
public InputStream getInputStreamForResource(String resource) {
// METAGEN-75
if ( !resource.startsWith( RESOURCE_PATH_SEPARATOR ) ) {
resource = RESOURCE_PATH_SEPARATOR + resource;
}
String pkg = getPackage( resource );
String name = getRelativeName( resource );
InputStream ormStream;
try {
FileObject fileObject = context.getProcessingEnvironment()
.getFiler()
.getResource( StandardLocation.CLASS_OUTPUT, pkg, name );
ormStream = fileObject.openInputStream();
}
catch ( IOException e1 ) {
// TODO - METAGEN-12
// unfortunately, the Filer.getResource API seems not to be able to load from /META-INF. One gets a
// FilerException with the message with "Illegal name /META-INF". This means that we have to revert to
// using the classpath. This might mean that we find a persistence.xml which is 'part of another jar.
// Not sure what else we can do here
ormStream = this.getClass().getResourceAsStream( resource );
}
return ormStream;
}
public Schema getSchema(String schemaResource) throws XmlParsingException {
Schema schema = SCHEMA_CACHE.get( schemaResource );
if ( schema != null ) {
return schema;
}
schema = loadSchema( schemaResource );
Schema previous = SCHEMA_CACHE.putIfAbsent( schemaResource, schema );
return previous != null ? previous : schema;
}
public <T> T getJaxbRoot(InputStream stream, Class<T> clazz, Schema schema)
throws XmlParsingException {
XMLEventReader staxEventReader;
try {
staxEventReader = createXmlEventReader( stream );
}
catch ( XMLStreamException e ) {
throw new XmlParsingException( "Unable to create stax reader", e );
}
ContextProvidingValidationEventHandler handler = new ContextProvidingValidationEventHandler();
try {
staxEventReader = new JpaNamespaceTransformingEventReader( staxEventReader );
JAXBContext jaxbContext = JAXBContext.newInstance( ObjectFactory.class );
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
unmarshaller.setSchema( schema );
unmarshaller.setEventHandler( handler );
return clazz.cast( unmarshaller.unmarshal( staxEventReader ) );
}
catch ( JAXBException e ) {
StringBuilder builder = new StringBuilder();
builder.append( "Unable to perform unmarshalling at line number " );
builder.append( handler.getLineNumber() );
builder.append( " and column " );
builder.append( handler.getColumnNumber() );
builder.append( ". Message: " );
builder.append( handler.getMessage() );
throw new XmlParsingException( builder.toString(), e );
}
}
private synchronized XMLEventReader createXmlEventReader(InputStream xmlStream) throws XMLStreamException {
return XML_INPUT_FACTORY.createXMLEventReader( xmlStream );
}
private String getPackage(String resourceName) {
if ( !resourceName.contains( Constants.PATH_SEPARATOR ) ) {
return "";
}
else {
return resourceName.substring( 0, resourceName.lastIndexOf( Constants.PATH_SEPARATOR ) );
}
}
private String getRelativeName(String resourceName) {
if ( !resourceName.contains( Constants.PATH_SEPARATOR ) ) {
return resourceName;
}
else {
return resourceName.substring( resourceName.lastIndexOf( Constants.PATH_SEPARATOR ) + 1 );
}
}
private Schema loadSchema(String schemaName) throws XmlParsingException {
Schema schema = null;
URL schemaUrl = this.getClass().getClassLoader().getResource( schemaName );
if ( schemaUrl == null ) {
return schema;
}
SchemaFactory sf = SchemaFactory.newInstance( javax.xml.XMLConstants.W3C_XML_SCHEMA_NS_URI );
try {
schema = sf.newSchema( schemaUrl );
}
catch ( SAXException e ) {
throw new XmlParsingException( "Unable to create schema for " + schemaName + ": " + e.getMessage(), e );
}
return schema;
}
}