com.flyingspaniel.nava.callback

Class Callbacks

java.lang.Object

com.flyingspaniel.nava.callback.Callbacks

public class Callbacks
extends Object

Utilities for dealing with Callbacks

Since:

Copyright (c) 2013 by Morgan Conrad

Author:

Morgan Conrad

See Also:

This software is released under the MIT License

Method Summary

Methods

Modifier and Type	Method and Description
static <IN,OUT> Callable	callableCallback(Callback<IN,OUT> callback, Exception ex, IN inData, Object... more) Convert any Callback into a Callable
static Callable	callableRunASync(ExecutorService xs, Callback first, Object inData, Object... more) By wrapping runASyncInLine() in a Callable, we can now run *everything* off the original thread.
static Callable	callableRunSync(Callback first, Object inData, Object... more) Wraps runSync() in a Callable so it can be run in another thread
static Callback	chainUp(Callback first, Callback... others) Create a chain of Callbacks, by setting nextCallback along the line...
static Exception	getCause(ExecutionException ee) Utility to get the cause from an ExecutionException as an Exception, not a Throwable
static Object[]	getMore(Callback callback) Utility to get the more results (or an empty []) from a callback
static Object	runASyncInLine(ExecutorService xs, Callback callback, Object data, Object... more) Runs a completedCallback (and any associated chain) using an ExecutorService However, since we wait for the Futures "in line" here, no real speed gain (see runASyncInLine)
static Object	runSync(Callback callback, Object data, Object... more) Runs a callback (and any associated chain) synchronously

Methods inherited from class java.lang.Object

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

Method Detail

chainUp

public static Callback chainUp(Callback first,
               Callback... others)

Create a chain of Callbacks, by setting nextCallback along the line...

Parameters:

first -

others -

Returns:

first

runSync

public static Object runSync(Callback callback,
             Object data,
             Object... more)
                      throws Exception

Runs a callback (and any associated chain) synchronously

Parameters:

callback - first callback, if null, data will be returned immediately

data - input to first callback

Returns:

result from the final callback

Throws:

Exception

callableRunSync

public static Callable callableRunSync(Callback first,
                       Object inData,
                       Object... more)

Wraps runSync() in a Callable so it can be run in another thread

Parameters:

first - if null, returns inData

inData - inputs to the first callback

more - inputs to the first callback

Returns:

result from the final callback

runASyncInLine

public static Object runASyncInLine(ExecutorService xs,
                    Callback callback,
                    Object data,
                    Object... more)
                             throws Exception

Runs a completedCallback (and any associated chain) using an ExecutorService However, since we wait for the Futures "in line" here, no real speed gain (see runASyncInLine)

Parameters:

xs - if null, they get run sync

callback - if null, returns inData

data - inputs to the first callback

more - inputs to the first callback

Returns:

result from the final callback

Throws:

Exception

callableRunASync

public static Callable callableRunASync(ExecutorService xs,
                        Callback first,
                        Object inData,
                        Object... more)

By wrapping runASyncInLine() in a Callable, we can now run *everything* off the original thread. However, see CallbackExecutor for a better alternative

Parameters:

xs -

first -

inData -

Returns:

Callable

See Also:

for a better alternative

callableCallback

public static <IN,OUT> Callable callableCallback(Callback<IN,OUT> callback,
                                 Exception ex,
                                 IN inData,
                                 Object... more)

Convert any Callback into a Callable

Parameters:

callback - if null this returns null

ex - input to the Callback

inData - input to the Callback

Returns:

a Callable, or null

getMore

public static Object[] getMore(Callback callback)

Utility to get the more results (or an empty []) from a callback

Parameters:

callback - non-null

Returns:

returns [] if callback is not a Callback.ProducesMore

getCause

public static Exception getCause(ExecutionException ee)

Utility to get the cause from an ExecutionException as an Exception, not a Throwable

Parameters:

ee - may be null

Returns:

null if ee is null

Throws:

Error - if ee wrapped an Error