Module de.cuioss.java.tools

Package de.cuioss.tools.collect

Class CollectionBuilder<E>

java.lang.Object

de.cuioss.tools.collect.CollectionBuilder<E>

Type Parameters:

E - The type of the contained Collection

All Implemented Interfaces:

Iterable<E>

public final class CollectionBuilder<E>
extends Object
implements Iterable<E>

Overview

Builder for creating Collections providing some convenience methods. The class writes everything through into the contained collector. Using the default constructor a newly created ArrayList will be used as collector, but you can pass you own collector as constructor-argument. Of course this should be mutable in order to work.

Handling of null-values

As default null values are ignored. This behavior can be changed by call addNullValues(boolean). Caution: In case of using one of the copyFrom(Collection) methods for instantiation the null values will not be checked in that way

Standard Usage

 List<String> result = new CollectionBuilder<String>().add("this").add("that").add(mutableList("on", "or an other"))
         .toImmutableList();
 

or

 Set<String> result = new CollectionBuilder<String>().add("this").add("that").add(mutableList("on", "or an other"))
         .toMutableSet();
 

Copy From

This methods can be used for ensuring a real copy

 List<String> result = CollectionBuilder.copyFrom(mutableList("on", "or an other")).add("element").toMutableList();

 

Sorting

The contained Collection can be sorted any time by calling sort(Comparator)

Author:

Oliver Wolff

Constructor Summary

Constructors

Constructor	Description
CollectionBuilder()	Default Constructor initializing the collector with an ArrayList
CollectionBuilder(Collection<E> collector)	Constructor for CollectionBuilder.

Method Summary

Modifier and Type	Method	Description
CollectionBuilder<E>	add(E e)	add.
final CollectionBuilder<E>	add(E... elements)	add.
CollectionBuilder<E>	add(Iterable<E> elements)	add.
CollectionBuilder<E>	add(Collection<E> elements)	add.
CollectionBuilder<E>	add(Optional<E> element)	add.
CollectionBuilder<E>	add(Stream<E> elements)	add.
CollectionBuilder<E>	addNullValues(boolean addNullValues)	addNullValues.
CollectionBuilder<E>	clear()	Clears the elements in the collector
boolean	contains(Object o)	contains.
static <E> CollectionBuilder<E>	copyFrom(E source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
static <E> CollectionBuilder<E>	copyFrom(E... source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
static <E> CollectionBuilder<E>	copyFrom(Iterable<? extends E> source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
static <E> CollectionBuilder<E>	copyFrom(Collection<? extends E> source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
static <E> CollectionBuilder<E>	copyFrom(Iterator<? extends E> source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
static <E> CollectionBuilder<E>	copyFrom(Stream<? extends E> source)	Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)
boolean	isEmpty()	isEmpty.
Iterator<E>	iterator()
int	size()	size.
CollectionBuilder<E>	sort(Comparator<? super E> comparator)	Sorts the contained Collection.
Stream<E>	stream()	stream.
E[]	toArray(Class<? super E> targetType)	toArray.
List<E>	toConcurrentList()	toConcurrentList.
NavigableSet<E>	toConcurrentNavigableSet()	toConcurrentNavigableSet.
Set<E>	toConcurrentSet()	toConcurrentSet.
List<E>	toImmutableList()	toImmutableList.
NavigableSet<E>	toImmutableNavigableSet()	toImmutableNavigableSet.
Set<E>	toImmutableSet()	toImmutableSet.
List<E>	toMutableList()	toMutableList.
NavigableSet<E>	toMutableNavigableSet()	toMutableNavigableSet.
Set<E>	toMutableSet()	toMutableSet.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

CollectionBuilder

public CollectionBuilder(Collection<E> collector)

Constructor for CollectionBuilder.

Parameters:

collector - to be used for storage. Must not be null

CollectionBuilder

public CollectionBuilder()

Default Constructor initializing the collector with an ArrayList

Method Details

addNullValues

public CollectionBuilder<E> addNullValues(boolean addNullValues)

addNullValues.

Parameters:

addNullValues - If set to true null elements are added to the contained collector, if false, default value, null values are ignored.

Returns:

the instance itself in order to use it in a fluent way.

size

public int size()

size.

Returns:

the size of the contained Collection

isEmpty

public boolean isEmpty()

isEmpty.

Returns:

see Collection.isEmpty()

contains

public boolean contains(Object o)

contains.

Parameters:

o - a Object object

Returns:

see Collection.isEmpty()

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Iterable<E>

stream

public Stream<E> stream()

stream.

Returns:

a Stream on the contained objects

add

public CollectionBuilder<E> add(E e)

add.

Parameters:

e - the element to be added

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

add

@SafeVarargs
public final CollectionBuilder<E> add(E... elements)

add.

Parameters:

elements - to be added

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

add

public CollectionBuilder<E> add(Iterable<E> elements)

add.

Parameters:

elements - to be added

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

add

public CollectionBuilder<E> add(Collection<E> elements)

add.

Parameters:

elements - to be added

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

add

public CollectionBuilder<E> add(Optional<E> element)

add.

Parameters:

element - to be added if present. Caution: passing an Optional parameter is a not a good thing to do, I know, but in this context it is quite convenient: Don't do this at home

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

add

public CollectionBuilder<E> add(Stream<E> elements)

add.

Parameters:

elements - to be added

Returns:

the instance itself in order to use it in a fluent way. Caution: with this call the return value of Collection.add(Object) will be ignored.

sort

public CollectionBuilder<E> sort(Comparator<? super E> comparator)

Sorts the contained Collection.

Parameters:

comparator - must not be null.

Returns:

the instance itself in order to use it in a fluent way.

toMutableList

public List<E> toMutableList()

toMutableList.

Returns:

a mutable List representation of the builders content, the actual implementation is an ArrayList

toImmutableList

public List<E> toImmutableList()

toImmutableList.

Returns:

an immutable List representation of the builders content, the actual implementation calls Collections.unmodifiableList(List). The underlying Collection will be copied by calling toMutableList()

toMutableSet

public Set<E> toMutableSet()

toMutableSet.

Returns:

a mutable Set representation of the builders content, the actual implementation is an HashSet

toImmutableSet

public Set<E> toImmutableSet()

toImmutableSet.

Returns:

an immutable Set representation of the builders content, the actual implementation calls Collections.unmodifiableList(List). The underlying Collection will be copied by calling toMutableSet()

toConcurrentList

public List<E> toConcurrentList()

toConcurrentList.

Returns:

a concurrent mutable List representation of the builders content, the actual implementation is an CopyOnWriteArrayList

toConcurrentSet

public Set<E> toConcurrentSet()

toConcurrentSet.

Returns:

a concurrent mutable Set representation of the builders content, the actual implementation is an CopyOnWriteArraySet

toMutableNavigableSet

public NavigableSet<E> toMutableNavigableSet()

toMutableNavigableSet.

Returns:

a mutable NavigableSet representation of the builders content, the actual implementation is an TreeSet. The assumption is that the Actual type is at least Comparable

toImmutableNavigableSet

public NavigableSet<E> toImmutableNavigableSet()

toImmutableNavigableSet.

Returns:

an immutable NavigableSet representation of the builders content, the actual implementation is an TreeSet wrapped by Collections.unmodifiableNavigableSet(NavigableSet). The assumption is that the Actual type is at least Comparable

toConcurrentNavigableSet

public NavigableSet<E> toConcurrentNavigableSet()

toConcurrentNavigableSet.

Returns:

a mutable NavigableSet representation of the builders content, the actual implementation is an ConcurrentSkipListSet. The assumption is that the actual type is at least Comparable

toArray

public E[] toArray(Class<? super E> targetType)

toArray.

Parameters:

targetType - identifying the concrete ArrayType

Returns:

an array representation of the builders content

clear

public CollectionBuilder<E> clear()

Clears the elements in the collector

Returns:

the instance itself in order to use it in a fluent way.

copyFrom

public static <E> CollectionBuilder<E> copyFrom(Iterable<? extends E> source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder

copyFrom

public static <E> CollectionBuilder<E> copyFrom(Iterator<? extends E> source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder

copyFrom

public static <E> CollectionBuilder<E> copyFrom(Collection<? extends E> source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder

copyFrom

public static <E> CollectionBuilder<E> copyFrom(Stream<? extends E> source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder

copyFrom

@SafeVarargs
public static <E> CollectionBuilder<E> copyFrom(E... source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder

copyFrom

public static <E> CollectionBuilder<E> copyFrom(E source)

Creates an Instance of CollectionBuilder by copying the content of the given source Caution: The given source will be used as it is, there will be no filtering as defined within addNullValues(boolean)

Type Parameters:

E - a E class

Parameters:

source - may be null

Returns:

the newly created CollectionBuilder