브라우저 자바 애플릿에서 싱글톤 객체 문제

class Queue2Object extends Thread {
   MyObjectHandler objectHandler = null;
   Queue q = null;
   boolean runFlag = true;
 
   private Queue2Object(MyObjectHandler m,Queue q){
      this.objectHandler = m;
      this.q = q;
   }
   public void run(){
       while(runFlag){
           if(!q.isEmpty()){
               syncronized(Queue.<span>MONITOR</span>){
                  objectHandler.add(q.pop());
               }
           }           
           // 생략
       }
   }
}

class ObjectQueue implement Queue{
   private static <span>instance</span> = null;
   private LinkedList<Object> list = null;
   private ObjectQueue(){
      list = new LinkedList<Object>();
   }
   public static Queue getInstance(){
      if(null != <span>instance</span>) <span>instance</span> = new ObjectQueue();
      return <span>instance</span>;       
   }
   public Object pop(){
     // 생략
   }
   public void put(Object o){
    //생략
   //...
}