我正在使用JEE,我创建了EJB-Singleton。它具有字段LRUMap,表示用于在应用程序中存储数据的缓存。我想在单例内清除数据,或者只是在运行时杀死并重新启动整个单例。有没有选择定期这样做?例如,为了清除数据,每天重置一次单独的bean?
这是代码:
@Singleton
@ConcurrencyManagement(ConcurrencyManagementType.CONTAINER)
public class BpNotificationCacheBean {
private static final int CACHE_SIZE = 1000;
private Map<String, Boolean> cacheMap;
@PostConstruct
public void init() {
cacheMap = new LRUMap(CACHE_SIZE);
}
@Lock(LockType.WRITE)
public Boolean get(String businessPartnerId) {
return cacheMap.get(businessPartnerId);
}
@Lock(LockType.WRITE)
public void put(String businessPartnerId, Boolean isVIP) {
this.cacheMap.put(businessPartnerId, isVIP);
}
}
如果你在一个完整的JEE环境中,我会创建一个Schedule
注释方法:
import javax.ejb.Schedule;
@Singleton
@ConcurrencyManagement(ConcurrencyManagementType.CONTAINER)
public class BpNotificationCacheBean {
private static final int CACHE_SIZE = 1000;
private Map<String, Boolean> cacheMap;
...
@Lock(LockType.WRITE)
@Schedule(hour = "1", persistent = false)
private void resetCache() {
cacheMap = new LRUMap(CACHE_SIZE);
}
}
关键是Schedule annotation,它是Java EE Timer Service的一部分。我显示的注释每天运行01:00(凌晨1点),但请参阅文档以显示如何更改它。