Spring中的事件监听机制在项目中的应用

最经在做项目的时候，调用某个接口的时候为了调用地图，而不希望因为调用超时影响到主线程，使用了spring的时间监听机制。

Spring中提供一些Aware相关的接口，BeanFactoryAware、 ApplicationContextAware、ResourceLoaderAware、ServletContextAware等等，其中最常用到的是ApplicationContextAware。实现ApplicationContextAware的Bean，在Bean被初始后，将会被注入ApplicationContext的实例。ApplicationContextAware提供了publishEvent()方法，实现Observer(观察者)设计模式的事件传播机，提供了针对Bean的事件传播功能。通过Application.publishEvent方法，我们可以将事件通知系统内所有的ApplicationListener。

Spring事件处理一般过程：

◆定义Event类，继承org.springframework.context.ApplicationEvent。

◆编写发布事件类Publisher，实现org.springframework.context.ApplicationContextAware接口。

◆覆盖方法setApplicationContext(ApplicationContext applicationContext)和发布方法publish(Object obj)。

◆定义时间监听类EventListener，实现ApplicationListener接口，实现方法onApplicationEvent(ApplicationEvent event)。

项目中的伪代码

定义Event类，继承org.springframework.context.ApplicationEvent。

public class Gis0002SuccessEvent extends ApplicationEvent
{

/**
* <B>Summary:</B> <Br>
* serialVersionUID:TODO（用一句话描述这个变量表示什么） <Br>
*
* @since Ver @version
*/
private static final long   serialVersionUID    = 1L;

public Gis0002SuccessEvent ( GiS0002 source )
{

super ( source );
}

}

2.编写发布事件类Publisher，实现org.springframework.context.ApplicationContextAware接口。

3.覆盖方法setApplicationContext(ApplicationContext applicationContext)和发布方法publish(Object obj)。

public class AgA01003ServiceImpl implements AgA01003Service,ApplicationContextAware{
//把救援人的信息传给地图  2015.07.21
public void dealMapMoniter(AgA01003Entity aga01003Entity){
GiS0002 giS0002 = new GiS0002();
log.info("--救援监控救援人信息数据---"+JsonUtil.toJSONString ( aga01003Entity ));
/******************以下是处理工单服务人员信息数据  begin*****************************/
giS0002.setTicketID  ( aga01003Entity.getTicketID ( ) );
4000
//工单编号
giS0002.setRescueName  ( aga01003Entity.getRescueName ( ) );//救援人员名称
giS0002.setRescuePhone  ( aga01003Entity.getRescuePhone ( ) );//救援人员电话
//giS0002.setRealServiceType( aga01003Entity.getServiceCode ( ) );//服务项目代码
//设置服务中文名称 edit by zhaolei 2015-08-03
String serviceName = sendMessageService.getSpTypeMateDataNameByCode(aga01003Entity.getServiceCode ( ));
giS0002.setRealServiceType( serviceName );//服务项目代码
giS0002.setRescueLatitude  ( aga01003Entity.getCaseLatitude ( ) );
giS0002.setRescueLongitude ( aga01003Entity.getCaseLongitude ( ) );
giS0002.setRescueVehicleNo  ( aga01003Entity.getRescueVehicleNo ( ) );//车牌号

//因调用地图时，如超时，会影响到主流程，所以改为监听 2015.08.10
this.ac.publishEvent ( new Gis0002SuccessEvent ( giS0002 ) );
}
}

定义时间监听类EventListener，实现ApplicationListener接口，实现方法onApplicationEvent(ApplicationEvent event)。

public class Gis0002Listener implements SmartApplicationListener
{

Logger log = LoggerFactory.getLogger ( Gis0002Listener.class );
@Resource( name = "dictionaryService" )
private DictionaryService           dictionaryService;
@Resource(name="logManagerSerivce")
private LogManagerSerivceImpl logManageService;
@Override
@Async //配置成异步处理数据
public void onApplicationEvent ( ApplicationEvent arg0 )
{
GiS0002  giS0002 = (GiS0002)arg0.getSource ( );

Enum enums = dictionaryService.searchByCode (   InitSpring.getMessage ( "RUNTIMEENUM" ) ,
"monitorRescue" );
//从配置库中取得接口url
String urlName = enums.getName ( );
log.info("救援监控救援人信息接口="+urlName);

JacksonJsonSimpleMarshaller sm = new JacksonJsonSimpleMarshaller ( );
String resJson = sm.marshaller ( giS0002 ,new ByteArrayOutputStream ( ) );
log.info("救援监控救援人信息请求参数="+resJson);
List<NameValuePair> json =  new ArrayList<NameValuePair> ( );
json.add ( new BasicNameValuePair ( "RequestBodyJson" , resJson ) );
try
{
//调用救援缄口地图
String returnData = HttpUtils.httpPost (urlName , json );
log.info("救援监控救援人信息接口返回="+JsonUtil.toJSONString ( returnData ));

if( returnData.matches ( ".*404.*" ) ){
logManageService.saveLog ( giS0002 , returnData ,"" ,
"", giS0002.getTicketID ( ) ,
"1" , Contants.GiS0002 );
}

}
catch ( HttpHostConnectException e )
{
log.error ( e.getMessage ( ) );
logManageService.saveLog ( giS0002 , "" ,e.getMessage ( ) ,
"", giS0002.getTicketID ( ) ,
"1" , Contants.GiS0002 );
}

}

@Override
public int getOrder ( )
{
return 1;
}

@Override
public boolean supportsEventType ( Class<? extends ApplicationEvent> eventType )
{
return eventType == Gis0002SuccessEvent.class;
}

@Override
public boolean supportsSourceType ( Class<?> sourceType )
{
return sourceType ==GiS0002.class;
}

}