Flex与Spring整合时SpringFactory

package flex.messaging.service;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;

import flex.messaging.FactoryInstance;
import flex.messaging.FlexFactory;
import flex.messaging.config.ConfigMap;
import flex.messaging.services.ServiceException;

/**
* This interface is implemented by factory components which provide
* instances to the flex messaging framework.  To configure flex data services
* to use this factory, add the following lines to your services-config.xml
* file (located in the WEB-INF/flex directory of your web application).
*
*	<factories>
*     <factory id="spring" class="flex.samples.factories.SpringFactory" />
*  </factories>
*
* You also must configure the web application to use spring and must copy the spring.jar
* file into your WEB-INF/lib directory.  To configure your app server to use spring,
* you add the following lines to your WEB-INF/web.xml file:
*
*   <context-param>
*        <param-name>contextConfigLocation</param-name>
*        <param-value>/WEB-INF/applicationContext.xml</param-value>
*   </context-param>
*
*   <listener>
*       <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
*   </listener>
*
* Then you put your spring bean configuration in WEB-INF/applicationContext.xml (as per the
* line above).  For example:
*
*  <?xml version="1.0" encoding="UTF-8"?>
*  <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
*
*  <beans>
*    <bean name="weatherBean" class="dev.weather.WeatherService" singleton="true"/>
*  </beans>
*
* Now you are ready to define a destination in flex that maps to this existing service.
* To do this you'd add this to your WEB-INF/flex/remoting-config.xml:
*
*  <destination id="WeatherService">
*      <properties>
*          <factory>spring</factory>
*          <source>weatherBean</source>
*      </properties>
*  </destination>
*
* @author Jeff Vroom
*/
public class SpringFactory implements FlexFactory
{
private static final String SOURCE = "source";

/**
* This method can be used to initialize the factory itself.  It is called with configuration
* parameters from the factory tag which defines the id of the factory.
*/
public void initialize(String id, ConfigMap configMap) {}

/**
* This method is called when we initialize the definition of an instance
* which will be looked up by this factory.  It should validate that
* the properties supplied are valid to define an instance.
* Any valid properties used for this configuration must be accessed to
* avoid warnings about unused configuration elements.  If your factory
* is only used for application scoped components, this method can simply
* return a factory instance which delegates the creation of the component
* to the FactoryInstance's lookup method.
*/
public FactoryInstance createFactoryInstance(String id, ConfigMap properties)
{
SpringFactoryInstance instance = new SpringFactoryInstance(this, id, properties);
instance.setSource(properties.getPropertyAsString(SOURCE, instance.getId()));
return instance;
} // end method createFactoryInstance()

/**
* Returns the instance specified by the source
* and properties arguments.  For the factory, this may mean
* constructing a new instance, optionally registering it in some other
* name space such as the session or JNDI, and then returning it
* or it may mean creating a new instance and returning it.
* This method is called for each request to operate on the
* given item by the system so it should be relatively efficient.
* <p>
* If your factory does not support the scope property, it
* report an error if scope is supplied in the properties
* for this instance.
*/
public Object lookup(FactoryInstance inst)
{
SpringFactoryInstance factoryInstance = (SpringFactoryInstance) inst;
return factoryInstance.lookup();
}

static class SpringFactoryInstance extends FactoryInstance
{
SpringFactoryInstance(SpringFactory factory, String id, ConfigMap properties)
{
super(factory, id, properties);
}

public String toString()
{
return "SpringFactory instance for id=" + getId() + " source=" + getSource() + " scope=" + getScope();
}

public Object lookup()
{
ApplicationContext appContext = WebApplicationContextUtils.getWebApplicationContext(flex.messaging.FlexContext.getServletConfig().getServletContext());
String beanName = getSource();

try
{
return appContext.getBean(beanName);
}
catch (NoSuchBeanDefinitionException nexc)
{
ServiceException e = new ServiceException();
String msg = "Spring service named '" + beanName + "' does not exist.";
e.setMessage(msg);
e.setRootCause(nexc);
e.setDetails(msg);
e.setCode("Server.Processing");
throw e;
}
catch (BeansException bexc)
{
ServiceException e = new ServiceException();
String msg = "Unable to create Spring service named '" + beanName + "' ";
e.setMessage(msg);
e.setRootCause(bexc);
e.setDetails(msg);
e.setCode("Server.Processing");
throw e;
}
}

}

}