net.sf.jstuff.integration.serviceregistry.support.ServiceAsSpringBean Maven / Gradle / Ivy

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/*
 * Copyright 2010-2022 by Sebastian Thomschke and contributors.
 * SPDX-License-Identifier: EPL-2.0
 */
package net.sf.jstuff.integration.serviceregistry.support;

import static net.sf.jstuff.core.validation.NullAnalysisHelper.*;

import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;

import net.sf.jstuff.core.validation.Args;
import net.sf.jstuff.core.validation.Assert;
import net.sf.jstuff.integration.serviceregistry.ServiceRegistry;

/**
 * Helper class to expose services registered with the {@link ServiceRegistry} as Spring beans.
 * 
 * I.e. the service will be looked up in the given serviceRegistry made available for injection into other Spring-managed beans.
 *
 * 
 * {@code
 * 
 *     
 *     
 *     
 *     
 * 
 * }
 * 
 *
 * @author Sebastian Thomschke
 */
public class ServiceAsSpringBean<@NonNull T> implements FactoryBean, InitializingBean {

   private ServiceRegistry serviceRegistry = lazyNonNull();

   /**
    * @optional by default the fully qualified name of the service interface is used
    */
   private @Nullable String serviceEndpointId;
   private Class serviceInterface = lazyNonNull();
   private T service = lazyNonNull();

   @Override
   public synchronized void afterPropertiesSet() throws Exception {
      Assert.isNull(service, "Already initialized!");
      Assert.notNull(serviceRegistry, "[serviceRegistry] must not be null!");
      Assert.notNull(serviceInterface, "[serviceInterface] must not be null!");

      service = serviceRegistry.getService(//
         serviceEndpointId != null ? serviceEndpointId : serviceInterface.getName(), //
         serviceInterface //
      ).get();
   }

   @Override
   public T getObject() throws Exception {
      return service;
   }

   @Override
   public Class getObjectType() {
      return serviceInterface;
   }

   @Override
   public boolean isSingleton() {
      return true;
   }

   public synchronized void setServiceEndpointId(final String serviceEndpointId) {
      Args.notNull("serviceEndpointId", serviceEndpointId);
      Assert.isNull(service, "Already initialized!");

      this.serviceEndpointId = serviceEndpointId;
   }

   public synchronized void setServiceInterface(final Class serviceInterface) {
      Args.notNull("serviceInterface", serviceInterface);
      Assert.isNull(service, "Already initialized!");
      Assert.isTrue(serviceInterface.isInterface(), "[serviceInterface] must be an interface but is " + serviceInterface);

      this.serviceInterface = serviceInterface;
   }

   public synchronized void setServiceRegistry(final ServiceRegistry serviceRegistry) {
      Args.notNull("serviceRegistry", serviceRegistry);
      Assert.isNull(service, "Already initialized!");

      this.serviceRegistry = serviceRegistry;
   }
}