Package com.helger.commons.state

Class ChangeWithValue<DATATYPE>

java.lang.Object

com.helger.commons.state.ChangeWithValue<DATATYPE>

Type Parameters:

DATATYPE - The data type that is wrapped together with the change indicator

All Implemented Interfaces:

IChangeIndicator, IWrapper<DATATYPE>, Supplier<DATATYPE>

@Immutable
public class ChangeWithValue<DATATYPE>
extends Object
implements IChangeIndicator, IWrapper<DATATYPE>

Wraps a change indicator and an arbitrary value.

Author:

Philip Helger

Constructor Summary

Constructors

Constructor	Description
ChangeWithValue(IChangeIndicator aChangeIndicator, DATATYPE aObj)	Constructor

Method Summary

Modifier and Type	Method	Description
static <DATATYPE> ChangeWithValue<DATATYPE>	createChanged(DATATYPE aValue)	Create a new changed object with the given value.
static <DATATYPE> ChangeWithValue<DATATYPE>	createUnchanged(DATATYPE aValue)	Create a new unchanged object with the given value.
boolean	equals(Object o)
DATATYPE	get()
DATATYPE	getIfChanged(DATATYPE aUnchangedValue)	Get the store value if this is a change.
DATATYPE	getIfChangedOrNull()	Get the store value if this is a changed.
DATATYPE	getIfUnchanged(DATATYPE aChangedValue)	Get the store value if this is unchanged.
DATATYPE	getIfUnchangedOrNull()	Get the store value if this is unchanged.
int	hashCode()
boolean	isChanged()
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.helger.commons.state.IChangeIndicator

and, and, isUnchanged, or, or

Methods inherited from interface com.helger.commons.wrapper.IWrapper

isNotSet, isSet

Constructor Detail

ChangeWithValue

public ChangeWithValue(@Nonnull
                       IChangeIndicator aChangeIndicator,
                       @Nullable
                       DATATYPE aObj)

Constructor

Parameters:

aChangeIndicator - The change indicator. May not be null.

aObj - The assigned value. May be null.

Method Detail

isChanged

public boolean isChanged()

Specified by:

isChanged in interface IChangeIndicator

Returns:

true if changed and false if unchanged.

get

@Nullable
public DATATYPE get()

Specified by:

get in interface IWrapper<DATATYPE>

Specified by:

get in interface Supplier<DATATYPE>

Returns:

The currently wrapped object. May be null.

getIfChanged

@Nullable
public DATATYPE getIfChanged(@Nullable
                             DATATYPE aUnchangedValue)

Get the store value if this is a change. Otherwise the passed unchanged value is returned.

Parameters:

aUnchangedValue - The unchanged value to be used. May be null.

Returns:

Either the stored value or the unchanged value. May be null.

getIfChangedOrNull

@Nullable
public DATATYPE getIfChangedOrNull()

Get the store value if this is a changed. Otherwise null is returned.

Returns:

Either the stored value or null.

getIfUnchanged

@Nullable
public DATATYPE getIfUnchanged(@Nullable
                               DATATYPE aChangedValue)

Get the store value if this is unchanged. Otherwise the passed changed value is returned.

Parameters:

aChangedValue - The changed value to be used. May be null.

Returns:

Either the stored value or the changed value. May be null.

getIfUnchangedOrNull

@Nullable
public DATATYPE getIfUnchangedOrNull()

Get the store value if this is unchanged. Otherwise null is returned.

Returns:

Either the stored value or null.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

createChanged

@Nonnull
public static <DATATYPE> ChangeWithValue<DATATYPE> createChanged(@Nullable
                                                                 DATATYPE aValue)

Create a new changed object with the given value.

Type Parameters:

DATATYPE - The data type that is wrapped together with the change indicator

Parameters:

aValue - The value to be used. May be null.

Returns:

Never null.

createUnchanged

@Nonnull
public static <DATATYPE> ChangeWithValue<DATATYPE> createUnchanged(@Nullable
                                                                   DATATYPE aValue)

Create a new unchanged object with the given value.

Type Parameters:

DATATYPE - The data type that is wrapped together with the change indicator

Parameters:

aValue - The value to be used. May be null.

Returns:

Never null.