Provide abstractions for transferring a SecurityContext across threads.
The main concepts are the DelegatingSecurityContextCallable and the
DelegatingSecurityContextRunnable which contain a SecurityContext to establish before
delegating to a Callable or Runnable.
There are also wrapper implementations for each of the key java.util.concurrent and
spring task interfaces to make using the DelegatingSecurityContextCallable and
DelegatingSecurityContextRunnable transparent to users. For example a
DelegatingSecurityContextTaskExecutor which can be injected with a specific
SecurityContext or use the SecurityContext from the SecurityContextHolder at the time the
task is submitted. There are similar implementations for each of the key
java.util.concurrent and spring task interfaces.
Note that in order to get DelegatingSecurityContextExecutorService to compile with
JDK 5 or JDK 6 we could not use type safe methods. See
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6267833 for details.
Rob Winch
51fd83060e