Java/Spring/IoC Context

Context Aware Demo

/*
Pro Spring
By Rob Harrop
Jan Machacek
ISBN: 1-59059-461-4
Publisher: Apress
*/
///////////////////////////////////////////////////////////////////////////////
//File: aware.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="contextAware" class="ContextAwareDemo"/>
</beans>
///////////////////////////////////////////////////////////////////////////////
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class ContextAwareDemo implements ApplicationContextAware {
    private ApplicationContext ctx;
    public void setApplicationContext(ApplicationContext applicationContext)
            throws BeansException {
        ctx = applicationContext;
    }
    public static void main(String[] args) {
        ApplicationContext ctx = new FileSystemXmlApplicationContext(
                "build/aware.xml");
        
        ContextAwareDemo demo = (ContextAwareDemo) ctx.getBean("contextAware");
        demo.displayAppContext();
    }
    public void displayAppContext() {
        System.out.println(ctx);
    }
}

Message Event

/*
Pro Spring
By Rob Harrop
Jan Machacek
ISBN: 1-59059-461-4
Publisher: Apress
*/

///////////////////////////////////////////////////////////////////////////////////////
//File: events.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="publisher" class="Publisher"/>
        <bean id="messageEventListener" class="MessageEventListener"/>
</beans>

///////////////////////////////////////////////////////////////////////////////////////
import org.springframework.context.ApplicationEvent;

public class MessageEvent extends ApplicationEvent {
    private String msg;
    public MessageEvent(Object source, String msg) {
        super(source);
        this.msg = msg;
    }
    
    public String getMessage() {
        return msg;
    }
    
}
///////////////////////////////////////////////////////////////////////////////////////
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
public class MessageEventListener implements ApplicationListener {
   
    public void onApplicationEvent(ApplicationEvent event) {
       if(event instanceof MessageEvent) {
           MessageEvent msgEvt = (MessageEvent)event;
           System.out.println("Received: " + msgEvt.getMessage());
       }
    }
}
///////////////////////////////////////////////////////////////////////////////////////

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class Publisher implements ApplicationContextAware {
    private ApplicationContext ctx;
    public static void main(String[] args) {
        ApplicationContext ctx = new FileSystemXmlApplicationContext(
                "build/events.xml");
        Publisher pub = (Publisher) ctx.getBean("publisher");
        pub.publish("Hello World!");
        pub.publish("The quick brown fox jumped over the lazy dog");
    }
    public void setApplicationContext(ApplicationContext applicationContext)
            throws BeansException {
        this.ctx = applicationContext;
    }
    public void publish(String message) {
        ctx.publishEvent(new MessageEvent(this, message));
    }
}