<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"
       default-autowire="byName">
 
    <!-- A processor that know about Person objects -->
    <bean id="personProcessor" class="com.raulraja.processor.impl.PersonProcessorImpl"/>
 
    <!-- A processor that knows about Place objects -->
    <bean id="placeProcessor" class="com.raulraja.processor.impl.PlaceProcessorImpl"/>
 
    <!-- A configured processing engine that maps object types to their processors and delegates calls to each one of them -->
    <bean id="processingEngine" class="com.raulraja.processor.impl.DefaultProcessingEngineImpl">
        <property name="processors">
            <map>
                <entry key="com.raulraja.domain.Person" value-ref="personProcessor"/>
                <entry key="com.raulraja.domain.Place" value-ref="placeProcessor"/>
            </map>
        </property>
    </bean>
 
    <!--
        This handler is actually not required but used for demonstrating the tutorial by invoking
        http://localhost:port/tutorialName
    -->
    <bean id="serviceInvokerHandler" class="com.raulraja.util.handler.impl.ServiceInvokerHandlerImpl" autowire="autodetect" />
 
</beans>

package com.raulraja.processor;
 
/**
 * A processing engine that you can feed objects to and processes them
 */
public interface ProcessingEngine<Target> {
 
	/**
	 * Processes something
	 * @param target the target object to be processed
	 */
	void process(Target target);
 
}

 
package com.raulraja.processor.impl;
 
import com.raulraja.processor.ProcessingEngine;
import com.raulraja.processor.Processor;
import org.apache.log4j.Logger;
 
import java.util.Map;
 
/**
 * Default impl of the processing engine based on a spring configured service.
 * Delegates processing calls to the right processor
 */
public class DefaultProcessingEngineImpl<Target> implements ProcessingEngine<Target> {
 
	private final static Logger log = Logger.getLogger(DefaultProcessingEngineImpl.class);
 
	/**
	 * A map of processor that maps object types to a processor that know how to process it
	 */
	private Map<Class<Target>, Processor<Target>> processors;
 
	public void setProcessors(Map<Class<Target>, Processor<Target>> processors) {
		this.processors = processors;
	}
 
	/**
	 * Processes something
	 *
	 * @param target the target object to be processed
	 */
	public void process(Target target) {
		log.debug("started processing " + target);
		Processor<Target> processor = processors.get(target.getClass());
		if (processor != null) {
			processor.process(target);
		} else {
			log.debug("processor not found for " + target);		
		}
		log.debug("finished processing " + target);
	}
}

package com.raulraja.processor;
 
/**
 * A service that know how to process a type of object
 */
public interface Processor<Target> {
 
	/**
	 * Processes something
	 * @param target the target object to be processed
	 */
	void process(Target target);
 
}

package com.raulraja.processor.impl;
 
import com.raulraja.domain.Person;
import com.raulraja.processor.Processor;
import org.apache.log4j.Logger;
 
/**
 * Demonstrates how a Person can be processed
 */
public class PersonProcessorImpl implements Processor<Person> {
 
	private final static Logger log = Logger.getLogger(PersonProcessorImpl.class);
 
	/**
	 * Processes something
	 *
	 * @param person the target object to be processed
	 */
	public void process(Person person) {
   		log.debug(person + " something is being done to a person object");
	}
}

package com.raulraja.processor.impl;
 
import com.raulraja.domain.Place;
import com.raulraja.processor.Processor;
import org.apache.log4j.Logger;
 
/**
 * Demonstrates how a Person can be processed
 */
public class PlaceProcessorImpl implements Processor<Place> {
 
	private final static Logger log = Logger.getLogger(PlaceProcessorImpl.class);
 
	/**
	 * Processes something
	 *
	 * @param place the target object to be processed
	 */
	public void process(Place place) {
   		log.debug(place + " something is being done to a place object");
	}
}

package com.raulraja.domain;
 
/**
 * Represents a person
 */
public class Person {
}

package com.raulraja.domain;
 
/**
 * Represents a place
 */
public class Place {
}

package com.raulraja.util.handler.impl;
 
import com.raulraja.processor.ProcessingEngine;
import com.raulraja.domain.Person;
import com.raulraja.domain.Place;
import org.springframework.web.HttpRequestHandler;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
/**
 * Frontend entry point for the demo
 */
public class ServiceInvokerHandlerImpl implements HttpRequestHandler {
 
	/**
	 * The engine that processes object types
	 */
	private ProcessingEngine<Object> processingEngine;
 
	/**
	 * sets the engine that processes object types
	 * @param processingEngine the engine
	 */
	public void setProcessingEngine(ProcessingEngine<Object> processingEngine) {
		this.processingEngine = processingEngine;
	}
 
	/**
	 * Process the given request, generating a response.
	 *
	 * @param request  current HTTP request
	 * @param response current HTTP response
	 * @throws javax.servlet.ServletException in case of general errors
	 * @throws java.io.IOException			in case of I/O errors
	 */
	public void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Person person = new Person();
		Place place = new Place();
		processingEngine.process(person);
		processingEngine.process(place);
	}
}