Qi4jApplicationBootstrap.java

/*  Copyright 2008 Edward Yakop.
 *
 * 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.qi4j.library.spring.bootstrap;

import org.qi4j.bootstrap.ApplicationAssembly;
import org.qi4j.bootstrap.AssemblyException;
import org.qi4j.bootstrap.ModuleAssembly;
import org.springframework.context.ApplicationContextAware;

/**
 * Run a Qi4j Application as a Spring Bean and export its Services to Spring.
 * 
 * Steps to export Qi4j service:
 * <ul>
 * <li>Create spring BeanFactory service of qi4j services to export.</li>
 * <li>Create a class that extends {@link Qi4jApplicationBootstrap}.</li>
 * <li>Sets the layer and module that register BeanFactory service.</li>
 * <li>Assemble qi4j application by implementing #assemble method.</li>
 * <li>Sets the identity of bean factory service. This identity is the spring
 * bean name.</li>
 * <li>Declare qi4j bootstrap in spring xml application context. <br/>
 * 
 * <pre>
 * <?xml version="1.0" encoding="UTF-8"?><br/>
 * <beans xmlns="http://www.springframework.org/schema/beans"
 * xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 * xmlns:qi4j="http://www.qi4j.org/schema/qi4j/spring"
 * xsi:schemaLocation="
 * http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
 * http://www.qi4j.org/schema/qi4j/spring http://www.qi4j.org/schema/qi4j/spring/spring-0.5.xsd">
 * <br/>
 * <!-- class that implements Qi4jApplicationBootstrap -->
 * <br/>
 * <qi4j:bootstrap class="org.qi4j.library.spring.bootstrap.Qi4jTestBootstrap"/>
 * <br/>
 * <bean id="commentServiceHolder" class="org.qi4j.library.spring.bootstrap.CommentServiceHolder">
 * <p/>
 * <constructor-arg ref="commentService"/> <!-- Reference qi4j comment service -->
 * <br/>
 * </bean>
 * </pre>
 * </li>
 * </ul>
 * <p/>
 * <p>
 * <b>Importing Spring beans as services</b><br/>
 * <ol>
 * <li>Application bootstrap class must implement interface
 * {@link ApplicationContextAware}.</li>
 * <li>In the application bootstrap import service to the module using method
 * {@link ModuleAssembly#importedServices(Class...)}.</li>
 * <li>Set concrete Spring bean as meta-data of the imported service.</li>
 * </ol>
 * </p>
 * 
 * Look at org.qi4j.library.spring.bootstrap.Qi4jExportServiceTest for sample
 * implementation.
 * 
 */
public abstract class Qi4jApplicationBootstrap
{
    /**
     * Assembles qi4j application.
     * 
     * @param applicationAssembly
     *            qi4j application assembly. Must not be {@code null}.
     * @throws AssemblyException
     *             Thrown if assemblies fails.
     */
    public abstract void assemble( ApplicationAssembly applicationAssembly ) throws AssemblyException;
}