Custom Events in Spring
Step | Description |
---|---|
1 | Create a project with a name SpringExample and create a package com.tutorialspoint under the src folder in the created project. All the classes will be created under this package. -> 이건 프로젝트 생성으로 처리됨. |
2 | Add required Spring libraries using Add External JARs option as explained in the Spring Hello World Example chapter. -> 이것도 처리됨. |
3 | Create an event class, CustomEvent by extending ApplicationEvent. This class must define a default constructor which should inherit constructor from ApplicationEvent class. |
4 | Once your event class is defined, you can publish it from any class, let us say EventClassPublisher which implements ApplicationEventPublisherAware. You will also need to declare this class in XML configuration file as a bean so that the container can identify the bean as an event publisher because it implements the ApplicationEventPublisherAware interface. |
5 | A published event can be handled in a class, let us say EventClassHandler which implements ApplicationListener interface and implements onApplicationEvent method for the custom event. |
6 | Create beans configuration file Beans.xml under the src folder and a MainApp class which will work as Spring application. |
7 | The final step is to create the content of all the Java files and Bean Configuration file and run the application as explained below. |
CustomEvent.java:
package com.tutorialspoint; import org.springframework.context.ApplicationEvent; public class CustomEvent extends ApplicationEvent{ public CustomEvent(Object source) { super(source); } public String toString(){ return "My Custom Event"; } }
CustomEventPublisher.java:
package com.tutorialspoint; import org.springframework.context.ApplicationEventPublisher; import org.springframework.context.ApplicationEventPublisherAware; public class CustomEventPublisher implements ApplicationEventPublisherAware { private ApplicationEventPublisher publisher; public void setApplicationEventPublisher (ApplicationEventPublisher publisher){ this.publisher = publisher; } public void publish() { CustomEvent ce = new CustomEvent(this); publisher.publishEvent(ce); } }
CustomEventHandler.java:
package com.tutorialspoint; import org.springframework.context.ApplicationListener; public class CustomEventHandler implements ApplicationListener<CustomEvent>{ public void onApplicationEvent(CustomEvent event) { System.out.println(event.toString()); } }
MainApp.java:
package com.tutorialspoint; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MainApp { public static void main(String[] args) { ConfigurableApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); CustomEventPublisher cvp = (CustomEventPublisher) context.getBean("customEventPublisher"); cvp.publish(); cvp.publish(); } }
Beans.xml:
<?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-3.0.xsd"> <bean id="customEventHandler" class="com.tutorialspoint.CustomEventHandler"/> <bean id="customEventPublisher" class="com.tutorialspoint.CustomEventPublisher"/> </beans>
실행 결과는 아래와 같다.
y Custom Event y Custom Event