/*
* JBoss, Home of Professional Open Source
* Copyright 2014, 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.jboss.weld.bootstrap;
import java.util.HashSet;
import java.util.Set;
import javax.annotation.Priority;
import org.jboss.weld.bootstrap.api.BootstrapService;
import org.jboss.weld.bootstrap.api.Service;
import org.jboss.weld.bootstrap.api.ServiceRegistry;
import org.jboss.weld.bootstrap.spi.BeanDeploymentArchive;
import org.jboss.weld.bootstrap.spi.Deployment;
import org.jboss.weld.bootstrap.spi.Metadata;
import org.jboss.weld.logging.BootstrapLogger;
import org.jboss.weld.resources.DefaultResourceLoader;
import org.jboss.weld.resources.WeldClassLoaderResourceLoader;
import org.jboss.weld.resources.spi.ResourceLoader;
import org.jboss.weld.transaction.spi.TransactionServices;
import org.jboss.weld.util.ServiceLoader;
import org.jboss.weld.util.reflection.Reflections;
/**
* Loads {@link Service} implementations using {@link ServiceLoader}. This can be used e.g. by a JTA library
* in weld-servlet environment to provide {@link TransactionServices} implementation which would not otherwise
* be provided by weld-servlet. Deployment classloaders, TCCL and Weld's classloader are used to discover service
* implementations. Service implementation may specify their priority using {@link Priority}. Services with higher
* priority have precedence. Services that do not specify priority have the default priority of 4500.
* See https://issues.jboss.org/browse/WELD-1495 for details.
*
* @author Jozef Hartinger
*
*/
class AdditionalServiceLoader {
private static final int DEFAULT_PLATFORM_PRIORITY = 4500;
private final Deployment deployment;
AdditionalServiceLoader(Deployment deployment) {
this.deployment = deployment;
}
/**
* Discovers additional services using {@link ServiceLoader} and appends them to the given service registry.
* @param registry the given service registry
*/
void loadAdditionalServices(ServiceRegistry registry) {
for (ResourceLoader loader : getResourceLoaders()) {
for (Metadata<Service> metadata : ServiceLoader.load(Service.class, loader)) {
Service service = metadata.getValue();
for (Class<? extends Service> serviceInterface : identifyServiceInterfaces(service.getClass(), new HashSet<>())) {
put(registry, serviceInterface, service);
}
}
}
}
/**
* Identifies service views for a service implementation class. A service view is either: - an interface that directly extends {@link Service} or
* {@link BootstrapService} - a clazz that directly implements {@link Service} or {@link BootstrapService}
*
* @param clazz the given class
* @param serviceInterfaces a set that this method populates with service views
* @return serviceInterfaces
*/
private Set<Class<? extends Service>> identifyServiceInterfaces(Class<?> clazz, Set<Class<? extends Service>> serviceInterfaces) {
if (clazz == null || Object.class.equals(clazz) || BootstrapService.class.equals(clazz)) {
return serviceInterfaces;
}
for (Class<?> interfac3 : clazz.getInterfaces()) {
if (Service.class.equals(interfac3) || BootstrapService.class.equals(interfac3)) {
serviceInterfaces.add(Reflections.cast(clazz));
}
}
for (Class<?> interfac3 : clazz.getInterfaces()) {
identifyServiceInterfaces(interfac3, serviceInterfaces);
}
identifyServiceInterfaces(clazz.getSuperclass(), serviceInterfaces);
return serviceInterfaces;
}
private <T extends Service> void put(ServiceRegistry registry, Class<T> key, Service value) {
Service previous = registry.get(key);
if (previous == null) {
BootstrapLogger.LOG.debugv("Installing additional service {0} ({1})", key.getName(), value.getClass());
registry.add(key, Reflections.cast(value));
} else if (shouldOverride(key, previous, value)) {
BootstrapLogger.LOG.debugv("Overriding service implementation for {0}. Previous implementation {1} is replaced with {2}", key.getName(), previous
.getClass().getName(), value.getClass().getName());
registry.add(key, Reflections.cast(value));
}
}
protected boolean shouldOverride(Class<? extends Service> key, Service previous, Service next) {
return getPriority(next) > getPriority(previous);
}
private int getPriority(Service service) {
Priority priority = service.getClass().getAnnotation(Priority.class);
if (priority != null) {
return priority.value();
}
return DEFAULT_PLATFORM_PRIORITY;
}
private Set<ResourceLoader> getResourceLoaders() {
Set<ResourceLoader> resourceLoaders = new HashSet<>();
for (BeanDeploymentArchive archive : deployment.getBeanDeploymentArchives()) {
ResourceLoader resourceLoader = archive.getServices().get(ResourceLoader.class);
if (resourceLoader != null) {
resourceLoaders.add(resourceLoader);
}
}
resourceLoaders.add(WeldClassLoaderResourceLoader.INSTANCE);
resourceLoaders.add(DefaultResourceLoader.INSTANCE);
return resourceLoaders;
}
}