org.apache.commons.lang3.tuple

Class Triple<L,M,R>

java.lang.Object

org.apache.commons.lang3.tuple.Triple<L,M,R>

Type Parameters:

L - the left element type.

M - the middle element type.

R - the right element type.

All Implemented Interfaces:

Serializable, Comparable<Triple<L,M,R>>

Direct Known Subclasses:

ImmutableTriple, MutableTriple

public abstract class Triple<L,M,R>
extends Object
implements Comparable<Triple<L,M,R>>, Serializable

A triple consisting of three elements.

This class is an abstract implementation defining the basic API. It refers to the elements as 'left', 'middle' and 'right'.

Subclass implementations may be mutable or immutable. However, there is no restriction on the type of the stored objects that may be stored. If mutable objects are stored in the triple, then the triple itself effectively becomes mutable.

Since:

3.2

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Triple<?,?,?>[]	EMPTY_ARRAY An empty array.

Constructor Summary

Constructors

Constructor and Description
Triple() Constructs a new instance.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Triple<L,M,R> other) Compares the triple based on the left element, followed by the middle element, finally the right element.
static <L,M,R> Triple<L,M,R>[]	emptyArray() Returns the empty array singleton that can be assigned without compiler warning.
boolean	equals(Object obj) Compares this triple to another based on the three elements.
abstract L	getLeft() Gets the left element from this triple.
abstract M	getMiddle() Gets the middle element from this triple.
abstract R	getRight() Gets the right element from this triple.
int	hashCode() Returns a suitable hash code.
static <L,M,R> Triple<L,M,R>	of(L left, M middle, R right) Obtains an immutable triple of three objects inferring the generic types.
static <L,M,R> Triple<L,M,R>	ofNonNull(L left, M middle, R right) Obtains an immutable triple of three non-null objects inferring the generic types.
String	toString() Returns a String representation of this triple using the format (left,middle,right).
String	toString(String format) Formats the receiver using the given format.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_ARRAY

public static final Triple<?,?,?>[] EMPTY_ARRAY

An empty array.

Consider using emptyArray() to avoid generics warnings.

Since:

3.10

Constructor Detail

Triple

public Triple()

Constructs a new instance.

Method Detail

emptyArray

public static <L,M,R> Triple<L,M,R>[] emptyArray()

Returns the empty array singleton that can be assigned without compiler warning.

Type Parameters:

L - the left element type.

M - the middle element type.

R - the right element type.

Returns:

the empty array singleton that can be assigned without compiler warning.

Since:

3.10

of

public static <L,M,R> Triple<L,M,R> of(L left,
                                       M middle,
                                       R right)

Obtains an immutable triple of three objects inferring the generic types.

This factory allows the triple to be created using inference to obtain the generic types.

Type Parameters:

L - the left element type.

M - the middle element type.

R - the right element type.

Parameters:

left - the left element, may be null.

middle - the middle element, may be null.

right - the right element, may be null.

Returns:

a triple formed from the three parameters, not null.

ofNonNull

public static <L,M,R> Triple<L,M,R> ofNonNull(L left,
                                              M middle,
                                              R right)

Obtains an immutable triple of three non-null objects inferring the generic types.

This factory allows the triple to be created using inference to obtain the generic types.

Type Parameters:

L - the left element type.

M - the middle element type.

R - the right element type.

Parameters:

left - the left element, may not be null.

middle - the middle element, may not be null.

right - the right element, may not be null.

Returns:

a triple formed from the three parameters, not null.

Throws:

NullPointerException - if any input is null.

Since:

3.13.0

compareTo

public int compareTo(Triple<L,M,R> other)

Compares the triple based on the left element, followed by the middle element, finally the right element. The types must be Comparable.

Specified by:

compareTo in interface Comparable<Triple<L,M,R>>

Parameters:

other - the other triple, not null.

Returns:

negative if this is less, zero if equal, positive if greater.

equals

public boolean equals(Object obj)

Compares this triple to another based on the three elements.

Overrides:

equals in class Object

Parameters:

obj - the object to compare to, null returns false.

Returns:

true if the elements of the triple are equal.

getLeft

public abstract L getLeft()

Gets the left element from this triple.

Returns:

the left element, may be null.

getMiddle

public abstract M getMiddle()

Gets the middle element from this triple.

Returns:

the middle element, may be null.

getRight

public abstract R getRight()

Gets the right element from this triple.

Returns:

the right element, may be null.

hashCode

public int hashCode()

Returns a suitable hash code.

The hash code is adapted from the definition in Map.Entry.

Overrides:

hashCode in class Object

Returns:

the hash code.

toString

public String toString()

Returns a String representation of this triple using the format (left,middle,right).

Overrides:

toString in class Object

Returns:

a string describing this object, not null.

toString

public String toString(String format)

Formats the receiver using the given format.

This uses Formattable to perform the formatting. Three variables may be used to embed the left and right elements. Use %1$s for the left element, %2$s for the middle and %3$s for the right element. The default format used by toString() is (%1$s,%2$s,%3$s).

Parameters:

format - the format string, optionally containing %1$s, %2$s and %3$s, not null.

Returns:

the formatted string, not null.