Multithreading in spring

I am trying to get into spring multithreading and I have few questions.

I have runnable method in ThreadRating class. Now I am not sure about the best way of using it.

option 1 I found:

private void updateRating() {
        ExecutorService executor = Executors.newFixedThreadPool(10);

    for (int i = 0; i < 10; i++) { // test
        // thread part
        Runnable worker = new ThreadRating(path, i, products.get(i), dao, fileHandler);
        executor.execute(worker);
    }
    executor.shutdown();
    try {
        executor.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
    } catch (InterruptedException e) {
        log.error("There was an error when ending threads");
        System.exit(1);
    }
    System.out.println("Finished all threads");
}

This seem to be running fine. After the for loop, it waits until threads are finished and ends.

Second option I tried

private TaskExecutor taskExecutor;

public UpdateBO(TaskExecutor taskExecutor) {
    this.taskExecutor = taskExecutor;
}

private void updateRating() {
        for (int i = 0; i < 10; i++) { // test
            Runnable worker = new ThreadRating(path, i, products.get(i), dao, fileHandler);
            taskExecutor.execute(worker);
        }
    // wait for threads to be finished before you go any further ??
        }

And in xml file I have

<beans:bean id="taskExecutor"
    class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
    <beans:property name="corePoolSize" value="5" />
    <beans:property name="maxPoolSize" value="10" />
    <beans:property name="queueCapacity" value="25" />
    <beans:property name="waitForTasksToCompleteOnShutdown" value="true" />
</beans:bean>

<beans:bean id="updateBO" class="UpdateBO">
    <beans:constructor-arg ref="taskExecutor" />
</beans:bean>

And here are my questions:

1. Is there any difference between these two options? Speed, memory, possible leaks? Or are they the same just written differently?


2. Do I need to shutdown the pool when using webservice? I know that in the second option I don't have to, but is it the same when using webservice?


3. When using second option - how should I tell to wait there until all jobs are finished? In the first option I just shut the pool down and wait to finish. But in the second option the code request is finished before the tasks are completed.


4. executor.execute(worker); - just to clarify. This is not actually creating a new thread, but it adds task to a queue and if the queue is full it waits right on this line in the code until there is free place?

Thanks for helping me understand.