/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.avalon.framework.configuration;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URL;
import java.util.Properties;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import org.xml.sax.helpers.NamespaceSupport;
A ConfigurationSerializer serializes configurations via SAX2 compliant parser.
Author: Avalon Development Team Version: $Id: DefaultConfigurationSerializer.java 506231 2007-02-12 02:36:54Z crossley $
/**
* A ConfigurationSerializer serializes configurations via SAX2 compliant parser.
*
* @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
* @version $Id: DefaultConfigurationSerializer.java 506231 2007-02-12 02:36:54Z crossley $
*/
public class DefaultConfigurationSerializer
{
private SAXTransformerFactory m_tfactory;
private Properties m_format = new Properties();
Sets the Serializer's use of indentation. This will cause linefeeds to be added
after each element, but it does not add any indentation via spaces.
Params: - indent – a
boolean
value
/**
* Sets the Serializer's use of indentation. This will cause linefeeds to be added
* after each element, but it does not add any indentation via spaces.
* @param indent a <code>boolean</code> value
*/
public void setIndent( boolean indent )
{
if( indent )
{
m_format.put( OutputKeys.INDENT, "yes" );
}
else
{
m_format.put( OutputKeys.INDENT, "no" );
}
}
Create a ContentHandler for an OutputStream
Params: - result – the result
Returns: contenthandler that goes to specified OutputStream
/**
* Create a ContentHandler for an OutputStream
* @param result the result
* @return contenthandler that goes to specified OutputStream
*/
protected ContentHandler createContentHandler( final Result result )
{
try
{
TransformerHandler handler = getTransformerFactory().newTransformerHandler();
m_format.put( OutputKeys.METHOD, "xml" );
handler.setResult( result );
handler.getTransformer().setOutputProperties( m_format );
return handler;
}
catch( final Exception e )
{
throw new RuntimeException( e.toString() );
}
}
Get the SAXTransformerFactory so we can get a serializer without being
tied to one vendor.
Returns: a SAXTransformerFactory
value
/**
* Get the SAXTransformerFactory so we can get a serializer without being
* tied to one vendor.
* @return a <code>SAXTransformerFactory</code> value
*/
protected SAXTransformerFactory getTransformerFactory()
{
if( m_tfactory == null )
{
m_tfactory = (SAXTransformerFactory)TransformerFactory.newInstance();
}
return m_tfactory;
}
Serialize the configuration to a ContentHandler
Params: - handler – a
ContentHandler
to serialize to - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize the configuration to a ContentHandler
* @param handler a <code>ContentHandler</code> to serialize to
* @param source a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public void serialize( final ContentHandler handler, final Configuration source )
throws SAXException, ConfigurationException
{
handler.startDocument();
serializeElement( handler, new NamespaceSupport(), source );
handler.endDocument();
}
Serialize each Configuration element. This method is called recursively.
Params: - handler – a
ContentHandler
to use - namespaceSupport – a
NamespaceSupport
to use - element – a
Configuration
value
Throws: - SAXException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize each Configuration element. This method is called recursively.
* @param handler a <code>ContentHandler</code> to use
* @param namespaceSupport a <code>NamespaceSupport</code> to use
* @param element a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws ConfigurationException if an error occurs
*/
protected void serializeElement( final ContentHandler handler,
final NamespaceSupport namespaceSupport,
final Configuration element )
throws SAXException, ConfigurationException
{
namespaceSupport.pushContext();
AttributesImpl attr = new AttributesImpl();
String[] attrNames = element.getAttributeNames();
if( null != attrNames )
{
for( int i = 0; i < attrNames.length; i++ )
{
attr.addAttribute( "", // namespace URI
attrNames[ i ], // local name
attrNames[ i ], // qName
"CDATA", // type
element.getAttribute( attrNames[ i ], "" ) // value
);
}
}
final String nsURI = element.getNamespace();
String nsPrefix = "";
if( element instanceof AbstractConfiguration )
{
nsPrefix = ( (AbstractConfiguration)element ).getPrefix();
}
// nsPrefix is guaranteed to be non-null at this point.
boolean nsWasDeclared = false;
final String existingURI = namespaceSupport.getURI( nsPrefix );
// ie, there is no existing URI declared for this prefix or we're
// remapping the prefix to a different URI
if( existingURI == null || !existingURI.equals( nsURI ) )
{
nsWasDeclared = true;
if( nsPrefix.equals( "" ) && nsURI.equals( "" ) )
{
// implicit mapping; don't need to declare
}
else if( nsPrefix.equals( "" ) )
{
// (re)declare the default namespace
attr.addAttribute( "", "xmlns", "xmlns", "CDATA", nsURI );
}
else
{
// (re)declare a mapping from nsPrefix to nsURI
attr.addAttribute( "", "xmlns:" + nsPrefix, "xmlns:" + nsPrefix, "CDATA", nsURI );
}
handler.startPrefixMapping( nsPrefix, nsURI );
namespaceSupport.declarePrefix( nsPrefix, nsURI );
}
String localName = element.getName();
String qName = element.getName();
if( nsPrefix == null || nsPrefix.length() == 0 )
{
qName = localName;
}
else
{
qName = nsPrefix + ":" + localName;
}
handler.startElement( nsURI, localName, qName, attr );
String value = element.getValue( null );
if( null == value )
{
Configuration[] children = element.getChildren();
for( int i = 0; i < children.length; i++ )
{
serializeElement( handler, namespaceSupport, children[ i ] );
}
}
else
{
handler.characters( value.toCharArray(), 0, value.length() );
}
handler.endElement( nsURI, localName, qName );
if( nsWasDeclared )
{
handler.endPrefixMapping( nsPrefix );
}
namespaceSupport.popContext();
}
Serialize the configuration object to a file using a filename.
Params: - filename – a
String
value - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- IOException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize the configuration object to a file using a filename.
* @param filename a <code>String</code> value
* @param source a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws IOException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public void serializeToFile( final String filename, final Configuration source )
throws SAXException, IOException, ConfigurationException
{
serializeToFile( new File( filename ), source );
}
Serialize the configuration object to a file using a File object.
Params: - file – a
File
value - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- IOException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize the configuration object to a file using a File object.
* @param file a <code>File</code> value
* @param source a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws IOException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public void serializeToFile( final File file, final Configuration source )
throws SAXException, IOException, ConfigurationException
{
OutputStream outputStream = null;
try
{
outputStream = new FileOutputStream( file );
serialize( outputStream, source );
}
finally
{
if( outputStream != null )
{
outputStream.close();
}
}
}
Serialize the configuration object to an output stream.
Params: - outputStream – an
OutputStream
value - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- IOException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize the configuration object to an output stream.
* @param outputStream an <code>OutputStream</code> value
* @param source a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws IOException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public void serialize( final OutputStream outputStream, final Configuration source )
throws SAXException, IOException, ConfigurationException
{
serialize( createContentHandler( new StreamResult( outputStream ) ), source );
}
Serialize the configuration object to an output stream derived from an
URI. The URI must be resolveable by the java.net.URL
object.
Params: - uri – a
String
value - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- IOException – if an error occurs
- ConfigurationException – if an error occurs
/**
* Serialize the configuration object to an output stream derived from an
* URI. The URI must be resolveable by the <code>java.net.URL</code> object.
* @param uri a <code>String</code> value
* @param source a <code>Configuration</code> value
* @throws SAXException if an error occurs
* @throws IOException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public void serialize( final String uri, final Configuration source )
throws SAXException, IOException, ConfigurationException
{
OutputStream outputStream = null;
try
{
outputStream = new URL( uri ).openConnection().getOutputStream();
serialize( outputStream, source );
}
finally
{
if( outputStream != null )
{
outputStream.close();
}
}
}
Serialize the configuration object to a string
Params: - source – a
Configuration
value
Throws: - SAXException – if an error occurs
- ConfigurationException – if an error occurs
Returns: configuration serialized as a string.
/**
* Serialize the configuration object to a string
* @param source a <code>Configuration</code> value
* @return configuration serialized as a string.
* @throws SAXException if an error occurs
* @throws ConfigurationException if an error occurs
*/
public String serialize( final Configuration source )
throws SAXException, ConfigurationException
{
final StringWriter writer = new StringWriter();
serialize( createContentHandler( new StreamResult( writer ) ), source );
return writer.toString();
}
}