Module com.github.robtimus.filesystems

Package com.github.robtimus.filesystems

Class CleanerSupport

java.lang.Object

com.github.robtimus.filesystems.CleanerSupport

public final class CleanerSupport
extends Object

A utility class for Cleaners.

Action for Cleaners cannot declare any checked exception to be thrown. When using Cleaners with file systems, it's common that the action can throw IOExceptions. The methods in this class allow such exceptions to be wrapped and unwrapped easily. The typical use is to call register(Cleaner, Object, CleanAction) to create Cleaner.Cleanable instances, and clean(Cleanable) to invoke these instances. This allows any IOException thrown from the action provided to register(Cleaner, Object, CleanAction) to be re-thrown when clean(Cleanable) is called.

Author:

Rob Spoor

Since:

3.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CleanerSupport.CleanAction	An action to invoke when objects become phantom reachable.

Method Summary

Modifier and Type	Method	Description
static void	clean(Cleaner.Cleanable cleanable)	Invokes a Cleaner.Cleanable, unwrapping any UncheckedIOException thrown by it.
static Cleaner.Cleanable	register(Cleaner cleaner, Object obj, CleanerSupport.CleanAction action)	Registers an object and a cleaning action in a Cleaner.

Methods inherited from class java.lang.Object

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

Method Detail

register

public static Cleaner.Cleanable register(Cleaner cleaner,
                                         Object obj,
                                         CleanerSupport.CleanAction action)

Registers an object and a cleaning action in a Cleaner. This method is a wrapper around Cleaner.register(Object, Runnable) that allows the action to throw IOExceptions. If the action throws an IOException when the returned Cleaner.Cleanable is called, an UncheckedIOException will be thrown. Use clean(Cleanable) instead of directly calling Cleaner.Cleanable.clean() to unwrap that exception.

Parameters:

cleaner - The Cleaner to register the given object and action in.

obj - The object to monitor.

action - The action to invoke when the object becomes phantom reachable.

Returns:

A Cleaner.Cleanable instance.

Throws:

NullPointerException - If the given Cleaner, object or action is null.

clean

public static void clean(Cleaner.Cleanable cleanable)
                  throws IOException

Invokes a Cleaner.Cleanable, unwrapping any UncheckedIOException thrown by it. Any other unchecked exception will be relayed to the caller.

Parameters:

cleanable - The Cleaner.Cleanable to invoke.

Throws:

NullPointerException - If the given Cleaner.Cleanable is null.

IOException - If the given Cleaner.Cleanable throws an UncheckedIOException.