org.apache.gobblin.util.callbacks

Class CallbacksDispatcher<L>

java.lang.Object

org.apache.gobblin.util.callbacks.CallbacksDispatcher<L>

All Implemented Interfaces:

Closeable, AutoCloseable

public class CallbacksDispatcher<L>
extends Object
implements Closeable

A helper to dispatch callbacks to a set of listeners. The CallbacksDispatcher is responsible for managing the list if listeners which implement a common interface L. Invocation happens through the #execCallbacks(CallbackFactory) method.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	CallbacksDispatcher.CallbackCallable<R>
static class	CallbacksDispatcher.CallbackResults<L,R>

Constructor Summary

Constructors

Constructor and Description
CallbacksDispatcher()
CallbacksDispatcher(ExecutorService execService, org.slf4j.Logger log)
CallbacksDispatcher(org.slf4j.Logger log)
CallbacksDispatcher(com.google.common.base.Optional<ExecutorService> execService, com.google.common.base.Optional<org.slf4j.Logger> log) Constructor

Method Summary

Modifier and Type	Method and Description
void	addListener(L listener)
void	addWeakListener(L listener) Only weak references are stored for weak listeners.
void	close()
<R> CallbacksDispatcher.CallbackResults<L,R>	execCallbacks(com.google.common.base.Function<? super L,R> callback)
<R> CallbacksDispatcher.CallbackResults<L,R>	execCallbacks(com.google.common.base.Function<? super L,R> callback, L listener)
static ExecutorService	getDefaultExecutor(org.slf4j.Logger log)
List<L>	getListeners()
org.slf4j.Logger	getLog()
void	removeListener(L listener)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CallbacksDispatcher

public CallbacksDispatcher(com.google.common.base.Optional<ExecutorService> execService,
                           com.google.common.base.Optional<org.slf4j.Logger> log)

Constructor

Parameters:

execService - optional executor services for the callbacks; if none is specified, a single-thread executor will be used

log - optional logger; if none is specified, a default one will be created

CallbacksDispatcher

public CallbacksDispatcher()

CallbacksDispatcher

public CallbacksDispatcher(org.slf4j.Logger log)

CallbacksDispatcher

public CallbacksDispatcher(ExecutorService execService,
                           org.slf4j.Logger log)

Method Detail

getDefaultExecutor

public static ExecutorService getDefaultExecutor(org.slf4j.Logger log)

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

getListeners

public List<L> getListeners()

addListener

public void addListener(L listener)

addWeakListener

public void addWeakListener(L listener)

Only weak references are stored for weak listeners. They will be removed from the dispatcher automatically, once the listener objects are GCed. Note that weak listeners cannot be removed explicitly.

removeListener

public void removeListener(L listener)

getLog

public org.slf4j.Logger getLog()

execCallbacks

public <R> CallbacksDispatcher.CallbackResults<L,R> execCallbacks(com.google.common.base.Function<? super L,R> callback,
                                                                  L listener)
                                                           throws InterruptedException

Throws:

InterruptedException

execCallbacks

public <R> CallbacksDispatcher.CallbackResults<L,R> execCallbacks(com.google.common.base.Function<? super L,R> callback)
                                                           throws InterruptedException

Throws:

InterruptedException