what does shutdown() really do
From javadoc 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. That is, calling execute() after shutdown() is an error. Sometimes I consider calling shutdown() a rule. Is it just used to forbid new tasks? Without calling shutdown(), what happens?
Mostly it is used to shutdown the ExecutorService i.e. stop it running when you don't need it. ExecutorServices contain a pool of threads. Threads are never cleaned up by the GC so you can't just discard them and assume the threads will clean themselves up. Once the threads have been told to stop they will do so after they complete the current task or almost immediately if otherwise idle. After they have stopped they can be cleaned up by the GC NOTE: Any ThreadLocal values will be retained until the Thread is cleaned up.
The shutdown() method prevents clients to send more work to the executor service i.e no new tasks will be accepted and all the existing tasks will still run to completion unless other actions are taken.Invocation has no additional effect if already shut down
The shutdown method (in short) starts all tasks, that may be submitted, but not yet started (which could be of type Future<E> for example) forbids submitting new tasks makes it possible to gracefully shut down
Generics with Hibernate
Access HttpServletRequest using #Context annotaion in business layer
Spring Security OAuth (separate client on angular2)
store map in list using hibernate createSQLQuery method
json jar for JSONOBJECT.getCurrentkey() , jsonobject.getMap()
Building a filter on a collection
Parse the SysML generated from Enterprise Architect in JAVA
Compiler warned me for making a fragment package-private; any other options?
Putting an JPanel into the foreground within another JPanel
Insert text into an XML node located by an XPath expression with Java code
arrayException in thread “main” java.util.NoSuchElementException
My code is not working, Because I didnot know that i am comparing them wrong. [closed]
Spring: Multiple controller instances of same class
Google Maps for android not rendering
Android Studio E/dalvikvm: Could not find class… referenced from method
Spring JDBC - .queryForObject() returns too many results?