/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2002 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, 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. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Jakarta", "Apache Avalon", "Avalon Framework" and
"Apache Software Foundation" must not be used to endorse or promote
products derived from this software without prior written
permission. For written permission, please contact apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
on behalf of the Apache Software Foundation. For more information on the
Apache Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.avalon.meta.info.builder;
import java.io.InputStream;
import java.util.Properties;
import java.util.ArrayList;
import org.apache.avalon.excalibur.i18n.ResourceManager;
import org.apache.avalon.excalibur.i18n.Resources;
import org.apache.avalon.framework.Version;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.meta.ConfigurationBuilder;
import org.apache.avalon.meta.info.Service;
import org.apache.avalon.meta.info.EntryDescriptor;
import org.apache.avalon.meta.info.ReferenceDescriptor;
import org.apache.avalon.meta.info.builder.BuildException;
import org.apache.excalibur.configuration.ConfigurationUtil;
import org.xml.sax.InputSource;
/**
* Utility class the handles the internalization of an XML description
* of a service into a {@link Service} instance.
*
* @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
* @version $Revision: 1.5 $ $Date: 2003/09/09 22:00:43 $
*/
public class XMLServiceCreator
implements ServiceCreator
{
private static final Resources REZ =
ResourceManager.getPackageResources( XMLServiceCreator.class );
/**
* Create a {@link Service} from stream
*
* @param key the name of the service type
* @param input the input stream that the resource is loaded from
* @return the created {@link Service}
* @exception Exception if an error occurs
*/
public Service createService( String key, InputStream input )
throws Exception
{
if( input == null )
{
throw new NullPointerException( "input" );
}
final InputSource source = new InputSource( input );
final Configuration xservice = ConfigurationBuilder.build( source );
return build( key, xservice );
}
/**
* Create a {@link Service} object for a supplied classname from
* configuration data.
*
* @param classname the classname of the service
* @param info the service defintion
* @return the created Service
* @throws BuildException if an error occurs
*/
private Service build( final String classname, final Configuration info )
throws BuildException
{
final String topLevelName = info.getName();
if( !topLevelName.equals( "service" ) )
{
final String message =
REZ.getString( "builder.bad-toplevel-service-element.error",
classname,
topLevelName );
throw new BuildException( message );
}
final Properties attributes =
buildAttributes( info.getChild( "attributes" ) );
final EntryDescriptor[] entries =
buildEntries( info.getChild( "entries" ).getChildren("entry") );
final String versionString = info.getChild( "version" ).getValue( "1.0" );
final Version version = buildVersion( versionString );
return new Service( new ReferenceDescriptor( classname, version ), entries, attributes );
}
/**
* Build up a list of attributes from specific config tree.
*
* @param config the attributes config
* @return the Properties object representing attributes
* @throws ConfigurationException if an error occurs
*/
public Properties buildAttributes( final Configuration config )
throws BuildException
{
final Properties attributes = new Properties();
final Configuration[] children = config.getChildren( "attribute" );
for( int i = 0; i < children.length; i++ )
{
Configuration child = children[ i ];
String key = null;
try
{
key = child.getAttribute( "key" );
}
catch( ConfigurationException ce )
{
final String error =
"Missing 'key' attribute in 'attribute' element.\n"
+ ConfigurationUtil.list( child );
throw new BuildException( error, ce );
}
String value = null;
try
{
value = child.getAttribute( "value" );
}
catch( Throwable e )
{
value = child.getValue( "" );
}
attributes.setProperty( key, value );
}
return attributes;
}
/**
* A utility method to build an array of {@link EntryDescriptor}
* objects from specified configuration.
*
* @param entrySet the set of entrys to build
* @return the created {@link EntryDescriptor}s
* @throws ConfigurationException if an error occurs
*/
protected EntryDescriptor[] buildEntries( final Configuration[] entrySet )
throws BuildException
{
final ArrayList entrys = new ArrayList();
for( int i = 0; i < entrySet.length; i++ )
{
final EntryDescriptor service = buildEntry( entrySet[ i ] );
entrys.add( service );
}
return (EntryDescriptor[])entrys.toArray( new EntryDescriptor[ entrys.size() ] );
}
/**
* Create a {@link EntryDescriptor} from configuration.
*
* @param config the configuration
* @return the created {@link EntryDescriptor}
* @throws ConfigurationException if an error occurs
*/
protected EntryDescriptor buildEntry( final Configuration config )
throws BuildException
{
try
{
final String key = config.getAttribute( "key" );
final String type = config.getAttribute( "type", "java.lang.String" );
final boolean isVolatile = config.getAttributeAsBoolean( "volatile", false );
final boolean optional =
config.getAttributeAsBoolean( "optional", false );
final String alias = config.getAttribute( "alias", null );
return new EntryDescriptor( key, type, optional, isVolatile, alias );
}
catch( Throwable e )
{
final String error =
"Unable to build entry descriptor."
+ ConfigurationUtil.list( config );
throw new BuildException( error, e );
}
}
/**
* A utility method to parse a Version object from specified string.
*
* @param version the version string
* @return the created Version object
*/
protected Version buildVersion( final String version )
throws BuildException
{
try
{
return Version.getVersion( version );
}
catch( Throwable e )
{
final String error =
REZ.getString( "builder.bad-version", version );
throw new BuildException( error, e );
}
}
}