org.faktorips.runtime.internal.tableindex

Class UniqueResultStructure<R>

java.lang.Object

org.faktorips.runtime.internal.tableindex.SearchStructure<R>

org.faktorips.runtime.internal.tableindex.UniqueResultStructure<R>

All Implemented Interfaces:

MergeAndCopyStructure<UniqueResultStructure<R>>

public class UniqueResultStructure<R>
extends SearchStructure<R>
implements MergeAndCopyStructure<UniqueResultStructure<R>>

UniqueResultStructures are the leaves in the tree of nested SearchStructures. Each UniqueResultStructure defines a result of a search. It is designed to hold exactly one value, in contrast to ResultStructures. Because of this UniqueResultStructures throw an UnsupportedOperationException when trying to merge them. The benefit is that setting up a SearchStructure with ambiguous results provokes an exception, even before it is put to use.

Method Summary

Methods

Modifier and Type	Method and Description
UniqueResultStructure<R>	copy() This method copies the object which calls it.
static <R> UniqueResultStructure<R>	createWith(R resultValue) Creates a new ResultSet with the given resultValue as its only result value.
boolean	equals(Object obj)
Set<R>	get() Returns the set of resulting values.
SearchStructure<R>	get(Object key) Returns the nested SearchStructure for the given key.
R	getUnique() Returns the value if there is exactly one value.
R	getUnique(R defaultValue) Returns the value if there is exactly one value or the given defaultValue if this structure is empty.
int	hashCode()
void	merge(UniqueResultStructure<R> otherStructure) Merging adds the contents of the otherMergable to this object.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

createWith

public static <R> UniqueResultStructure<R> createWith(R resultValue)

Creates a new ResultSet with the given resultValue as its only result value. The resultValue must not be null.

get

public SearchStructure<R> get(Object key)

Description copied from class: SearchStructure

Returns the nested SearchStructure for the given key. This method never returns null. If no value exists for a given key an EmptySearchStructure is returned as a fall-back.

Specified by:

get in class SearchStructure<R>

Parameters:

key - The key for the requested nested SearchStructure

Returns:

The nested SearchStructure or an EmptySearchStructure if the key does not exist.

get

public Set<R> get()

Description copied from class: SearchStructure

Returns the set of resulting values. If this SearchStructure is no ResultStructure this method simply aggregates every nested structures' results. Beware that the aggregation of nested elements has linear complexity.

Specified by:

get in class SearchStructure<R>

Returns:

The set of resulting values that are reachable by this SearchStructure

merge

public void merge(UniqueResultStructure<R> otherStructure)

Description copied from interface: MergeAndCopyStructure

Merging adds the contents of the otherMergable to this object. This object then contains the combined content. The other object remains unchanged.Merging a SearchStructure deletes no content, instead equal values are being merged recursively.

Specified by:

merge in interface MergeAndCopyStructure<UniqueResultStructure<R>>

Parameters:

otherStructure - The object that should be merged into this object

getUnique

public R getUnique(R defaultValue)

Description copied from class: SearchStructure

Returns the value if there is exactly one value or the given defaultValue if this structure is empty.

Use this method if you know there should be at most one result value. This method throws an AssertionError if there is more than one value.

Overrides:

getUnique in class SearchStructure<R>

Parameters:

defaultValue - The defaultValue which is returned if this SearchStructure is empty.

Returns:

The result hold by this SearchStructure or the defaultValue if the structure is empty.

getUnique

public R getUnique()

Description copied from class: SearchStructure

Returns the value if there is exactly one value.

Use this method if you know there should be exactly one result value. This method throws an AssertionError if there is more than one values. If there is no value it throws an NoSuchElementException exception.

Overrides:

getUnique in class SearchStructure<R>

Returns:

The one and only result hold by this SearchStructure.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

copy

public UniqueResultStructure<R> copy()

This method copies the object which calls it. The newly created object has the same properties like the object calling MergeAndCopyStructure.copy().

The UniqueResultStructure is immutable. Hence it is not needed to create a copy.

Specified by:

copy in interface MergeAndCopyStructure<UniqueResultStructure<R>>

Returns:

T that is a copy of the calling object