Spring ApplicationContext中的”事件传递“笔记

ApplicationContext中的事件处理是通过ApplicationEvent类和ApplicationListener接口来提供。通过ApplicationContext的publishEvent()方法来通知ApplicationListener。

下面是一个简单的测试例子。。。

第一步、创建一个类LogEvent用来继承ApplicationEvent

package spring.init.log;

import org.springframework.context.ApplicationEvent;

/**
 * @author fanbo
 * ApplicationContext事件传递Log例子
 * 继承org.springframework.context.ApplicationEvent;
 */
public class LogEvent extends ApplicationEvent{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    
    public LogEvent(Object msg) {
        super(msg);
        // TODO Auto-generated constructor stub
        System.out.println("LOGEVENT传过来的值"+msg);
    }
}

第二步、创建一个类LogListener用来实现ApplicationListener接口。

package spring.init.log;

import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;

/**
 * @author fanbo
 * ApplicationContext事件传递Log例子
 * 实现org.springframework.context.ApplicationListener;接口
 */
public class LogListener implements ApplicationListener{

    /*
     * 实现onApplicationEvent(non-Javadoc)
     * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
     */
    public void onApplicationEvent(ApplicationEvent event) {
        // TODO Auto-generated method stub
        //如果传递过来的参数是LogEvent的实例，
        if(event instanceof LogEvent){
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String nowdate = sdf.format(new Date());
            System.out.println("当前时间是："+nowdate);
        }
    }

}

第三步、创建一个类Log用来实现ApplicationContextAware接口

package spring.init.log;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

/**
 * @author fanbo
 *  ApplicationContext事件传递Log例子
 *  实现org.springframework.context.ApplicationContextAware;接口
 */
public class Log implements ApplicationContextAware{
    
    private ApplicationContext applicationContext;

    /*
     * 实现接口中的方法
     */
    public void setApplicationContext(ApplicationContext ac)
            throws BeansException {
        // TODO Auto-generated method stub
        this.applicationContext = ac;
        
    }
    
    /**
     * 通过ApplicationContext的publishEvent方法来传递给ApplicationListener
     * @param log
     * @return
     */
    public int LogInfo(String log){
        
        LogEvent le = new LogEvent(log);
        //通过ApplicationContext的publishEvent方法来传递给ApplicationListener
        this.applicationContext.publishEvent(le);
        return 1;
    }
    

}

第四步、配置Bean.xml文件

    <!-- ApplicationCOntext事件传递 -->
    <bean id="log" class="spring.init.log.Log" />
    <bean id="listener" class="spring.init.log.LogListener"></bean>
    

第五步、测试

package spring.init.log;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;

public class LogTest {

    public static void main(String[] args) {
        ApplicationContext ac = new FileSystemXmlApplicationContext("conf/xml/config.xml");
        Log log = (Log) ac.getBean("log");
        log.LogInfo("gf");
    }
}

输出结果

log4j:WARN No such property [maxFileSize] in org.apache.log4j.ConsoleAppender.
log4j:WARN No such property [file] in org.apache.log4j.ConsoleAppender.
log4j:WARN No such property [append] in org.apache.log4j.ConsoleAppender.
log4j:WARN No such property [maxBackupIndex] in org.apache.log4j.ConsoleAppender.
LOGEVENT传过来的值gf
当前时间是：2013-12-03 13:50:44