Package org.apache.commons.lang3.tuple

Class Triple<L,​M,​R>

  • Type Parameters:
    L - the left element type
    M - the middle element type
    R - the right element type
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<Triple<L,​M,​R>>
    Direct Known Subclasses:
    ImmutableTriple, MutableTriple
    public abstract class Triple<L,​M,​R>
extends java.lang.Object
implements java.lang.Comparable<Triple<L,​M,​R>>, java.io.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 Description
      static Triple<?,​?,​?>[] EMPTY_ARRAY
      An empty array.

    • Constructor Summary

      Constructors 
      Constructor Description
      Triple()  

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method 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​(java.lang.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.
      java.lang.String toString()
      Returns a String representation of this triple using the format ($left,$middle,$right).
      java.lang.String toString​(java.lang.String format)
      Formats the receiver using the given format.

      • Methods inherited from class java.lang.Object

        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()

    • 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

      • 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 java.lang.Comparable<L>
        Parameters:
        other - the other triple, not null
        Returns:
        negative if this is less, zero if equal, positive if greater

      • equals

        public boolean equals​(java.lang.Object obj)

        Compares this triple to another based on the three elements.

        Overrides:
        equals in class java.lang.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.

        Overrides:
        hashCode in class java.lang.Object
        Returns:
        the hash code

      • toString

        public java.lang.String toString()

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

        Overrides:
        toString in class java.lang.Object
        Returns:
        a string describing this object, not null

      • toString

        public java.lang.String toString​(java.lang.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