/*
* Copyright 2002-2007 the original author or authors.
*
* 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.springframework.beans.factory.serviceloader;
import java.util.ServiceLoader;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.config.AbstractFactoryBean;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* Abstract base class for FactoryBeans operating on the
* JDK 1.6 {@link java.util.ServiceLoader} facility.
*
* @author Juergen Hoeller
* @since 2.5
* @see java.util.ServiceLoader
*/
public abstract class AbstractServiceLoaderBasedFactoryBean extends AbstractFactoryBean
implements BeanClassLoaderAware {
private Class serviceType;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
/**
* Specify the desired service type (typically the service's public API).
*/
public void setServiceType(Class serviceType) {
this.serviceType = serviceType;
}
/**
* Return the desired service type.
*/
public Class getServiceType() {
return this.serviceType;
}
@Override
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = beanClassLoader;
}
/**
* Delegates to {@link #getObjectToExpose(java.util.ServiceLoader)}.
* @return the object to expose
*/
@Override
protected Object createInstance() {
Assert.notNull(getServiceType(), "Property 'serviceType' is required");
return getObjectToExpose(ServiceLoader.load(getServiceType(), this.beanClassLoader));
}
/**
* Determine the actual object to expose for the given ServiceLoader.
* <p>Left to concrete subclasses.
* @param serviceLoader the ServiceLoader for the configured service class
* @return the object to expose
*/
protected abstract Object getObjectToExpose(ServiceLoader serviceLoader);
}
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