org.mule.util.SpiUtils Maven / Gradle / Ivy
/*
* $Id: SpiUtils.java 23924 2012-02-29 00:50:53Z mike.schilling $
* --------------------------------------------------------------------------------------
* Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com
*
* The software in this package is published under the terms of the CPAL v1.0
* license, a copy of which has been included with this distribution in the
* LICENSE.txt file.
*/
package org.mule.util;
import org.mule.api.registry.ServiceType;
import org.mule.config.ExceptionHelper;
import org.mule.transport.service.TransportFactory;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.Properties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
// TODO This will eventually use the OSGi Service Registry for locating services
//@ThreadSafe
public class SpiUtils
{
private static final Log logger = LogFactory.getLog(SpiUtils.class);
public static final String SERVICE_ROOT = "META-INF/services/";
public static Properties findServiceDescriptor(ServiceType type, String name)
{
if (type.equals(ServiceType.TRANSPORT))
{
// for better EE transports support from earlier versions, try the preferred-xxx lookup first without fallback
Properties tsd = findServiceDescriptor(type.getPath(), name, TransportFactory.class, false);
if (tsd == null)
{
// regular flow
tsd = findServiceDescriptor(type.getPath(), name, TransportFactory.class);
}
return tsd;
}
else if (type.equals(ServiceType.EXCEPTION))
{
return findServiceDescriptor(type.getPath(), name, ExceptionHelper.class);
}
else
{
logger.warn("Attempt to lookup unrecognized service type: " + type);
return null;
}
}
public static Properties findServiceDescriptor(String path, String name, Class currentClass)
{
return findServiceDescriptor(path, name, currentClass, true);
}
/**
* @param fallbackToNonPreferred whether the search should attempt the preferred-xxx.properties lookup
*/
public static Properties findServiceDescriptor(String path, String name, Class currentClass, boolean fallbackToNonPreferred)
{
//Preferred name and preferred path - used to construct a URI for alternative or preferred
//property set. This enables alternative implementations of a transport to exist side by side
//in a single Mule VM. Most transports will not have a preferred property set.
String preferredName = null;
String preferredPath = null;
if (!name.endsWith(".properties"))
{
name += ".properties";
//convention is preferred-.properties
preferredName = "preferred-" + name;
}
if (path.startsWith("/"))
{
path = path.substring(1);
}
if (!path.endsWith("/"))
{
path += "/";
}
if (path.startsWith(SERVICE_ROOT))
{
path += name;
}
else
{
preferredPath = SERVICE_ROOT + path + preferredName;
path = SERVICE_ROOT + path + name;
}
try
{
//get preferred path first
InputStream is = IOUtils.getResourceAsStream(preferredPath, currentClass, false, false);
//if no resource found, then go with default path
if (is == null && fallbackToNonPreferred)
{
is = IOUtils.getResourceAsStream(path, currentClass, false, false);
}
if (is != null)
{
Properties props = new Properties();
try
{
props.load(is);
return props;
}
catch (IOException e)
{
logger.warn("Descriptor found but unable to load properties for service " + name);
return null;
}
}
else
{
return null;
}
}
catch (IOException e)
{
return null;
}
}
/**
* Find all resources of the given name and merge them
*/
public static Properties findServiceDescriptors(String path, String name, Class currentClass)
{
if (!name.endsWith(".properties"))
{
name += ".properties";
}
if (path.startsWith("/"))
{
path = path.substring(1);
}
if (!path.endsWith("/"))
{
path += "/";
}
if (path.startsWith(SERVICE_ROOT))
{
path += name;
}
else
{
path = SERVICE_ROOT + path + name;
}
try
{
Properties props = new Properties();
Enumeration urls = currentClass.getClassLoader().getResources(path);
while (urls.hasMoreElements())
{
URL url = urls.nextElement();
InputStream inputStream = null;
try
{
inputStream = url.openStream();
props.load(inputStream);
}
catch (IOException e)
{
logger.warn("Descriptor found but unable to load properties for service " + name);
}
finally
{
IOUtils.closeQuietly(inputStream);
}
}
return props;
}
catch (IOException e)
{
return null;
}
}
}