Initiates an orderly shutdown in which previously submitted
tasks are executed, but no new tasks will be accepted.
Invocation has no additional effect if already shut down.
<p>This method does not wait for previously submitted tasks to
complete execution. Use {@link #awaitTermination awaitTermination}
to do that.
Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. Invocation has no additional effect if already shut down.
<p>This method does not wait for previously submitted tasks to complete execution. Use {@link #awaitTermination awaitTermination} to do that.
@throws SecurityException {@inheritDoc}