/*
* 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 com.hp.hpl.jena.sparql.lib;
import java.io.IOException ;
import java.io.InputStream ;
import java.util.ArrayList ;
import java.util.InvalidPropertiesFormatException ;
import java.util.List ;
import java.util.Properties ;
import org.apache.jena.atlas.lib.SystemUtils ;
import org.apache.jena.atlas.logging.Log ;
import com.hp.hpl.jena.sparql.ARQException ;
/** Simple wrapper for reading metadata, once, from a system resource.
* Note that in some environments, it's tricky to get a class loader.
*/
public class Metadata
{
private List<String> resources = new ArrayList<String>() ;
private Properties properties = new Properties() ;
public Metadata() { }
public Metadata(String resourceName)
{
this() ;
addMetadata(resourceName) ;
}
public void addMetadata(String resourceName)
{
resources.add(resourceName) ;
read(properties, resourceName) ;
}
// Protect all classloader choosing -- sometimes systems mess with even the system class loader.
private static void read(Properties properties, String resourceName)
{
// Armour-plate this - classloaders and using them can be blocked by some environments.
try {
ClassLoader classLoader = null ;
try { classLoader = SystemUtils.chooseClassLoader() ; } catch (ARQException ex) {}
if (classLoader == null)
{
try { classLoader = Metadata.class.getClassLoader(); } catch (ARQException ex) {}
}
if ( classLoader == null )
{
Log.fatal(Metadata.class, "No classloader") ;
return ;
}
InputStream in = classLoader.getResourceAsStream(resourceName) ;
if ( in == null )
//throw new ARQException("Failed to find the properties file") ;
// In development, there is no properties file.
return ;
try { properties.loadFromXML(in) ; }
catch (InvalidPropertiesFormatException ex)
{ throw new ARQException("Invalid properties file", ex) ; }
catch (IOException ex)
{ throw new ARQException("Metadata ==> IOException", ex) ; }
}
catch (Throwable ex)
{
Log.fatal(Metadata.class, "Unexpected Thorwable", ex) ;
return ;
}
}
public String get(String name) { return get(name, null) ; }
public String get(String name, String defaultValue)
{
if ( properties == null ) return defaultValue ;
return properties.getProperty(name, defaultValue) ;
}
public List<String> getResources()
{
return resources ;
}
public Properties getProperties()
{
return properties ;
}
}