Package com.diffplug.spotless

Class LazyForwardingEquality<T extends Serializable>

java.lang.Object

com.diffplug.spotless.LazyForwardingEquality<T>

All Implemented Interfaces:

NoLambda, Serializable

public abstract class LazyForwardingEquality<T extends Serializable>
extends Object
implements Serializable, NoLambda

Implements equality, hashcode, and serialization entirely in terms of lazily-computed state. The state's serialized form is used to implement equals() and hashCode(), so you don't have to.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.diffplug.spotless.NoLambda

NoLambda.EqualityBasedOnSerialization

Constructor Summary

Constructors

Constructor	Description
LazyForwardingEquality()

Method Summary

Modifier and Type	Method	Description
protected abstract T	calculateState()	This function is guaranteed to be called at most once.
final boolean	equals(Object other)
final int	hashCode()
protected final T	state()	Returns the underlying state, possibly triggering a call to {calculateState().
byte[]	toBytes()	Returns a byte array representation of everything inside this SerializableFileFilter.
static void	unlazy(Object in)	Ensures that the lazy state has been evaluated.

Methods inherited from class java.lang.Object

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

Constructor Details

LazyForwardingEquality

public LazyForwardingEquality()

Method Details

calculateState

protected abstract T calculateState()
                             throws Exception

This function is guaranteed to be called at most once. If the state is never required, then it will never be called at all.

Throws exception because it's likely that there will be some IO going on.

Throws:

Exception

state

protected final T state()

Returns the underlying state, possibly triggering a call to {calculateState().

toBytes

public byte[] toBytes()

Description copied from interface: NoLambda

Returns a byte array representation of everything inside this SerializableFileFilter.

The main purpose of this method is to ensure one can't instantiate this class with lambda expressions, which are notoriously difficult to serialize and deserialize properly. (See SerializableFileFilterImpl.SkipFilesNamed for an example of how to make a serializable subclass.)

Specified by:

toBytes in interface NoLambda

equals

public final boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

unlazy

public static void unlazy(Object in)

Ensures that the lazy state has been evaluated.