如何从数据库加载和重置Web应用程序中的配置映射

我需要从数据库加载配置映射。配置映射表示为

   Hashtable<String, Hashtable<String,String>>

我们不能一开始就加载映射，因为我们依赖于另一个war应用程序进行数据库连接。所以，该映射被装载在类（singleton）的所述第一呼叫到配置ResourcesStorage实施ServletContextListener。同时，重置JSPreset()在此侦听器中调用静态方法。我使用reentrant锁添加了同步。我只锁定重置，因为不同的线程应该能够同时检索数据。但是，这不能很好地工作。

我正进入（状态

IllegalMonitorStateException  on notFull.await();   
java.lang.IllegalMonitorStateException
        at java.util.concurrent.locks.ReentrantLock$Sync.tryRelease(ReentrantLock.java:127)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.release(AbstractQueuedSynchronizer.java:1175)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.fullyRelease(AbstractQueuedSynchronizer.java:1606)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1922)

我的设计正确吗？

import java.util.Hashtable;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class ResourcesStorage implements ServletContextListener {

private static ResourcesStorage instance;
protected static Log log = LogFactory.getLog(ResourcesStorage.class);
protected Hashtable<String, Hashtable<String,String>> DBsettings =new Hashtable    <String, Hashtable<String,String>>();
private ServletContext context = null;
private boolean isLoading = false;

 public synchronized boolean isLoading() {
    return isLoading;
}

public  synchronized void setLoading(boolean isLoading) {
    this.isLoading = isLoading;
}

private Lock lock = new ReentrantLock();
private Condition notFull = lock.newCondition();

public void contextDestroyed(ServletContextEvent arg0) {}

public void contextInitialized(ServletContextEvent event) {

    this.context = event.getServletContext();
        //initialize the static reference _instance
    instance=this;
    reloadAllSettings();
}

public  Hashtable<String, Hashtable<String,String>> getDBSettings()
{
    return DBsettings;
}
public static String getSettings(String groupName, String keyName)
{
    ResourcesStorage instance = ResourcesStorage.getInstance();
    Hashtable<String, Hashtable<String,String>> dbsettings = instance.getDBSettings();
    Hashtable<String,String> group =(Hashtable<String,String>) dbsettings.get(groupName);
    if(group!=null && !group.isEmpty())
        return group.get(keyName);
    else
        return null;
}

public String getValueSettings (String groupName, String keyName)
{
    try 
    {
        while (isLoading() == false)
        {
             notFull.await();
        }
        Hashtable<String,String> group =(Hashtable<String,String>) DBsettings.get(groupName);
        if(group!=null && !group.isEmpty())
        {
            return group.get(keyName);
        }
        else
        {
            return null;
        }
    }
    catch (Exception e)
    {
        log.error("getValueSetting", e);    
    }
    return null;
}

public static void reSet(){
    ResourcesStorage instance = ResourcesStorage.getInstance();
    instance.reloadAllSettings();
}

public void reloadAllSettings(){
    lock.lock();
    setLoading(true);
    try
    {
// .....            
//getting resources from the database 
        setLoading(false);
        notFull.signal();
    } catch (Exception e) {
//...
    }
    finally
    {
        lock.unlock();
    }
}

public static ResourcesStorage getInstance() 
{
    return instance;
}

public ServletContext getContext() {
    return context;
}

public void setContext(ServletContext context) {
    this.context = context;
}
}