Flex集成spring需要的SpringFactory

package dsp.factory;

 

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;

            } 

        }

 

    } 

 

}