Spring-MVC的应用中，要实现类似的功能，主要是通过实现下面这些接口（任选一，至少一个即可）
一、ApplicationContextAware接口
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package org.springframework.context;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.Aware;
import org.springframework.context.ApplicationContext;
public interface ApplicationContextAware extends Aware {
void setApplicationContext(ApplicationContext var1) throws BeansException;
} |
二、ServletContextAware 接口
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package org.springframework.web.context;
import javax.servlet.ServletContext;
import org.springframework.beans.factory.Aware;
public interface ServletContextAware extends Aware {
void setServletContext(ServletContext var1);
} |
三、InitializingBean 接口
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package org.springframework.beans.factory;
public interface InitializingBean {
void afterPropertiesSet() throws Exception;
} |
四、ApplicationListener<ApplicationEvent> 接口
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package org.springframework.context;
import java.util.EventListener;
import org.springframework.context.ApplicationEvent;
public interface ApplicationListener<E extends ApplicationEvent> extends EventListener {
void onApplicationEvent(E var1);
} |
示例程序：
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package test.web.listener;
import org.apache.logging.log4j.*;
import org.springframework.beans.*;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.*;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
import org.springframework.web.context.ServletContextAware;
import javax.servlet.ServletContext;
@Componentpublic class StartupListener implements ApplicationContextAware, ServletContextAware,
InitializingBean, ApplicationListener<ContextRefreshedEvent> {
protected Logger logger = LogManager.getLogger();
@Override
public void setApplicationContext(ApplicationContext ctx) throws BeansException {
logger.info("1 => StartupListener.setApplicationContext");
}
@Override
public void setServletContext(ServletContext context) {
logger.info("2 => StartupListener.setServletContext");
}
@Override
public void afterPropertiesSet() throws Exception {
logger.info("3 => StartupListener.afterPropertiesSet");
}
@Override
public void onApplicationEvent(ContextRefreshedEvent evt) {
logger.info("4.1 => MyApplicationListener.onApplicationEvent");
if (evt.getApplicationContext().getParent() == null) {
logger.info("4.2 => MyApplicationListener.onApplicationEvent");
}
}
} |
运行时，输出的顺序如下：
1 => StartupListener.setApplicationContext
2 => StartupListener.setServletContext
3 => StartupListener.afterPropertiesSet
4.1 => MyApplicationListener.onApplicationEvent
4.2 => MyApplicationListener.onApplicationEvent
4.1 => MyApplicationListener.onApplicationEvent
注意：onApplicationEvent方法会触发多次，初始化这种事情，越早越好，建议在setApplicationContext方法中处理。
最后一步别忘了，在spring-config.xml中加入自定义的bean，如下面的例子：
<!--初始化操作的bean 在spring初始化完成的时候执行这个操作 --> <bean class="com.**.firm.fclient.web.listener.ApplicationContextListener"/>
此外还有一种方法：
写个BEAN，将要执行的操作写在构造函数里，在将这个类配置到XML里，比如配置到SPRING-MVC.XML里 <bean class="com.test.xx"> 自己的类
不过不推荐使用这种方法