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    copied!<p>Configure each extension in a separate application context. In each application context, define a <a href="http://static.springframework.org/spring/docs/2.5.x/reference/beans.html#beans-factory-extension-bpp" rel="nofollow noreferrer">BeanPostProcessor</a> which saves every bean the application context defines to a registry that maps beans to application contexts.</p> <p>Configure an application context which will be the parent for each extension application context. In this configuration file, define a bean which maps bean names to application context identifiers.</p> <pre><code>&lt;!-- parent.xml --&gt; &lt;beans&gt; &lt;bean id="beanNameToApplicationContextIdMap" class="java.util.HashMap"/&gt; &lt;/beans&gt; </code></pre> <p>The extension application context configuration file defines an instance of <code>BeanNameToApplicationContextIdMapInserter</code>, which is a custom class implementing the <code>BeanPostProcessor</code> interface. The <code>applicationContextId</code> property is configured to a string identifying the application context. The <code>map</code> property configures the instance to update the map defined in the parent application context.</p> <pre><code>&lt;!-- alpha.xml --&gt; &lt;beans&gt; &lt;bean class="com.example.BeanNameToApplicationContextIdMapInserter"&gt; &lt;property name="applicationContextId" value="alpha"/&gt; &lt;property name="map" ref="beanNameToApplicationContextIdMap"/&gt; &lt;/bean&gt; &lt;bean id="alphaService" class="..."&gt; &lt;/bean&gt; &lt;/beans&gt; </code></pre> <p>The <code>BeanNameToApplicationContextIdMapInserter</code> source code:</p> <pre><code>public class BeanNameToApplicationContextIdMapInserter implements BeanPostProcessor { private String applicationContextId; private HashMap&lt;String, String&gt; map; public void setApplicationContextId(String id) { this.applicationContextId = id; } public void setMap(HashMap&lt;String, String&gt; map) { this.map = map; } public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { return bean; } public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { map.put(beanName, applicationContextId); return bean; } } </code></pre> <p>You can use <a href="http://static.springframework.org/spring/docs/2.5.x/api/org/springframework/beans/factory/access/SingletonBeanFactoryLocator.html" rel="nofollow noreferrer">SingletonBeanFactoryLocator</a> to configure the parent application context and each extension application context.</p> <pre><code>&lt;!-- beanRefFactory.xml --&gt; &lt;beans&gt; &lt;bean id="parentApplicationContext" class="org.springframework.context.support.ClassPathXmlApplicationContext"&gt; &lt;constructor-arg&gt; &lt;value&gt;parent.xml&lt;/value&gt; &lt;/constructor-arg&gt; &lt;/bean&gt; &lt;bean id="alphaApplicationContext" class="org.springframework.context.support.ClassPathXmlApplicationContext"&gt; &lt;constructor-arg&gt; &lt;value&gt;alpha.xml&lt;/value&gt; &lt;/constructor-arg&gt; &lt;constructor-arg&gt; &lt;ref bean="parentApplicationContext"/&gt; &lt;/constructor-arg&gt; &lt;/bean&gt; &lt;bean id="bravoApplicationContext" class="org.springframework.context.support.ClassPathXmlApplicationContext"&gt; &lt;constructor-arg&gt; &lt;value&gt;bravo.xml&lt;/value&gt; &lt;/constructor-arg&gt; &lt;constructor-arg&gt; &lt;ref bean="parentApplicationContext"/&gt; &lt;/constructor-arg&gt; &lt;/bean&gt; &lt;/beans&gt; </code></pre> <p>Here is example code that reads the bean to application context map.</p> <pre><code>public class Main { private static ApplicationContext getApplicationContext(String name) { BeanFactoryLocator bfl = SingletonBeanFactoryLocator.getInstance(); BeanFactoryReference bfr = bfl.useBeanFactory(name); return (ApplicationContext) bfr.getFactory(); } public static void main(String[] args) { ApplicationContext parentApplicationContext = getApplicationContext("parentApplicationContext"); HashMap&lt;String, String&gt; map = (HashMap&lt;String, String&gt;) parentApplicationContext.getBean("beanNameToApplicationContextIdMap"); System.out.println(map.get("alphaService")); System.out.println(map.get("bravoService")); } } </code></pre>
 

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