Java 1.4 multi threading using ExecutorService - multithreading

Question

I'm trying to implement a multi-thread logic to send hsql request at the same time and at the end of all threads to get one list with all the results.
My thread class is the following:
public class QueryWorker implements Runnable {
private static Query query;
private List result;
private Exception exception;
private volatile boolean flag = false;
public QueryWorker(Query query) {
this.query = query;
}
public void run() {
try {
// System.out.println(method+" Start!!!");
this.result = invokeMethod(this.query);
this.flag = true;
// System.out.println(method+" finished!!!");
} catch (Exception e) {
this.exception = e;
}
}
public boolean isDaemon() {
return false;
}
public void release() {
}
private static List invokeMethod(Query query) throws SecurityException,
NoSuchMethodException, IllegalArgumentException,
IllegalAccessException, InvocationTargetException,
HibernateException {
List result = query.list();
return result;
}
public List getResult() {
while (!flag) {
System.out.println("blocked on the result");
this.run();
}
return result;
}
public void setResult(List result) {
this.result = result;
}
public Exception getException() {
return this.exception;
}
}
Next I just add the querys to the ExecutorService.
...
ExecutorService executor = Executors.newFixedThreadPool(2);
Runnable worker1 = new QueryWorker(q);
executor.execute(worker1);
...
Runnable worker2 = new QueryWorker(q);
executor.execute(worker2);
executor.shutdown();
try {
executor.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
while (!executor.isTerminated()) {
}
list = ((QueryWorker) worker1).getResult();
List list2 = ((QueryWorker) worker2).getResult();
list.addAll(list2);
} catch (InterruptedException e) {
// send error somewhere
}
The problem is that the program ends before I can get the result of both lists. I also looked at how to use ThreadPoolExecutor but I use java 1.4 so I can not aford the luxury of generic in order to use this class.