Module com.aoapps.lang

Package com.aoapps.lang.attribute

Class Attribute<C,T>

java.lang.Object

com.aoapps.lang.attribute.Attribute<C,T>

public abstract class Attribute<C,T>
extends Object

An attribute has scope, context, and name and is used for value access.

Author:

AO Industries, Inc.

See Also:

• Context
• Scope

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Attribute.Name<T>	A name without any specific scope or context.
static class	Attribute.OldValue	A backup value from before attribute initialization, which must be closed to restore the old value.

Field Summary

Fields

Modifier and Type	Field	Description
protected final String	name

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Attribute(String name)

Method Summary

Modifier and Type	Method	Description
static <T> Attribute.Name<T>	attribute(String name)	Attribute: Uses the given name, still needs scope or context.
abstract <Ex extends Throwable> T	compute(BiFunctionE<? super String,? super T,? extends T,? extends Ex> remappingFunction)	Much like Map.compute(java.lang.Object, java.util.function.BiFunction), but for this attribute.
abstract <Ex extends Throwable> T	computeIfAbsent(FunctionE<? super String,? extends T,? extends Ex> mappingFunction)	Much like Map.computeIfAbsent(java.lang.Object, java.util.function.Function), but for this attribute.
abstract <Ex extends Throwable> T	computeIfPresent(BiFunctionE<? super String,? super T,? extends T,? extends Ex> remappingFunction)	Much like Map.computeIfPresent(java.lang.Object, java.util.function.BiFunction), but for this attribute.
abstract T	get()	Gets the value of this attribute.
abstract Context<C>	getContext()	Gets the context for this attribute.
String	getName()	Gets the attribute name.
abstract T	getOrDefault(T defaultValue)	Much like Map.getOrDefault(java.lang.Object, java.lang.Object), but for this attribute.
abstract Attribute.OldValue	init(T value)	Initializes this attribute, returning a backup value, which must be closed to restore the old value.
abstract <Ex extends Throwable> T	merge(T value, BiFunctionE<? super T,? super T,? extends T,? extends Ex> remappingFunction)	Much like Map.merge(java.lang.Object, java.lang.Object, java.util.function.BiFunction), but for this attribute.
abstract void	remove()	Removes the value from this attribute.
abstract boolean	remove(T value)	Much like Map.remove(java.lang.Object, java.lang.Object), but for this attribute.
abstract T	replace(T value)	Much like Map.replace(java.lang.Object, java.lang.Object), but for this attribute.
abstract boolean	replace(T oldValue, T newValue)	Much like Map.replace(java.lang.Object, java.lang.Object, java.lang.Object), but for this attribute.
abstract void	set(T value)	Sets the value of this attribute.
abstract T	setIfAbsent(T value)	Much like Map.putIfAbsent(java.lang.Object, java.lang.Object), but for this attribute.

Methods inherited from class java.lang.Object

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

Field Details

name

protected final String name

Constructor Details

Attribute

protected Attribute(String name)

Method Details

getContext

public abstract Context<C> getContext()

Gets the context for this attribute.

Returns:

the context or null when none

getName

public String getName()

Gets the attribute name.

init

public abstract Attribute.OldValue init(T value)

Initializes this attribute, returning a backup value, which must be closed to restore the old value. This is best used in try-with-resources.

compute

public abstract <Ex extends Throwable> T compute(BiFunctionE<? super String,? super T,? extends T,? extends Ex> remappingFunction)
                                          throws Ex

Much like Map.compute(java.lang.Object, java.util.function.BiFunction), but for this attribute. Synchronizes on context to ensure atomic operation.

Throws:

Ex

See Also:

• Map.compute(java.lang.Object, java.util.function.BiFunction)

computeIfAbsent

public abstract <Ex extends Throwable> T computeIfAbsent(FunctionE<? super String,? extends T,? extends Ex> mappingFunction)
                                                  throws Ex

Much like Map.computeIfAbsent(java.lang.Object, java.util.function.Function), but for this attribute. Synchronizes on context to ensure atomic operation.

Throws:

Ex

See Also:

• Map.computeIfAbsent(java.lang.Object, java.util.function.Function)

computeIfPresent

public abstract <Ex extends Throwable> T computeIfPresent(BiFunctionE<? super String,? super T,? extends T,? extends Ex> remappingFunction)
                                                   throws Ex

Much like Map.computeIfPresent(java.lang.Object, java.util.function.BiFunction), but for this attribute. Synchronizes on context to ensure atomic operation.

Throws:

Ex

See Also:

• Map.computeIfPresent(java.lang.Object, java.util.function.BiFunction)

get

public abstract T get()

Gets the value of this attribute.

Returns:

getContext() may be null, which will return null

getOrDefault

public abstract T getOrDefault(T defaultValue)

Much like Map.getOrDefault(java.lang.Object, java.lang.Object), but for this attribute.

Returns:

getContext() may be null, which will return defaultValue

See Also:

• Map.getOrDefault(java.lang.Object, java.lang.Object)

merge

public abstract <Ex extends Throwable> T merge(T value,
 BiFunctionE<? super T,? super T,? extends T,? extends Ex> remappingFunction)
                                        throws Ex

Much like Map.merge(java.lang.Object, java.lang.Object, java.util.function.BiFunction), but for this attribute. Synchronizes on context to ensure atomic operation.

Throws:

Ex

See Also:

• Map.merge(java.lang.Object, java.lang.Object, java.util.function.BiFunction)

remove

public abstract void remove()

Removes the value from this attribute.

getContext() may be null, which will skip removal

remove

public abstract boolean remove(T value)

Much like Map.remove(java.lang.Object, java.lang.Object), but for this attribute. Synchronizes on context to ensure atomic operation.

See Also:

• Map.remove(java.lang.Object, java.lang.Object)

replace

public abstract T replace(T value)

Much like Map.replace(java.lang.Object, java.lang.Object), but for this attribute. Synchronizes on context to ensure atomic operation.

See Also:

• Map.replace(java.lang.Object, java.lang.Object)

replace

public abstract boolean replace(T oldValue,
 T newValue)

Much like Map.replace(java.lang.Object, java.lang.Object, java.lang.Object), but for this attribute. Synchronizes on context to ensure atomic operation.

See Also:

• Map.replace(java.lang.Object, java.lang.Object, java.lang.Object)

set

public abstract void set(T value)

Sets the value of this attribute.

setIfAbsent

public abstract T setIfAbsent(T value)

Much like Map.putIfAbsent(java.lang.Object, java.lang.Object), but for this attribute. Synchronizes on context to ensure atomic operation.

See Also:

• Map.putIfAbsent(java.lang.Object, java.lang.Object)

attribute

public static <T> Attribute.Name<T> attribute(String name)

Attribute: Uses the given name, still needs scope or context.