com.google.common.collect

Interface Multiset.Entry<E>

Enclosing interface:

Multiset<E>

public static interface Multiset.Entry<E>

An unmodifiable element-count pair for a multiset. The Multiset.entrySet() method returns a view of the multiset whose elements are of this class. A multiset implementation may return Entry instances that are either live "read-through" views to the Multiset, or immutable snapshots. Note that this type is unrelated to the similarly-named type Map.Entry.

Since:

2.0

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o) Indicates whether some other object is "equal to" this one.
int	getCount() Returns the count of the associated element in the underlying multiset.
E	getElement() Returns the multiset element corresponding to this entry.
int	hashCode() Returns a hash code value for the object.
String	toString() Returns the canonical string representation of this entry, defined as follows.

Method Detail

getElement

E getElement()

Returns the multiset element corresponding to this entry. Multiple calls to this method always return the same instance.

Returns:

the element corresponding to this entry

getCount

int getCount()

Returns the count of the associated element in the underlying multiset. This count may either be an unchanging snapshot of the count at the time the entry was retrieved, or a live view of the current count of the element in the multiset, depending on the implementation. Note that in the former case, this method can never return zero, while in the latter, it will return zero if all occurrences of the element were since removed from the multiset.

Returns:

the count of the element; never negative

equals

boolean equals(Object o)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Returns true if the given object is also a multiset entry and the two entries represent the same element and count. That is, two entries a and b are equal if:

   

   Objects.equal(a.getElement(), b.getElement())
       && a.getCount() == b.getCount()

Overrides:

equals in class Object

Parameters:

o - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Object.hashCode(), HashMap

hashCode

int hashCode()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

The hash code of a multiset entry for element element and count count is defined as:

   

   ((element == null) ? 0 : element.hashCode()) ^ count

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

toString

String toString()

Returns the canonical string representation of this entry, defined as follows. If the count for this entry is one, this is simply the string representation of the corresponding element. Otherwise, it is the string representation of the element, followed by the three characters " x " (space, letter x, space), followed by the count.

Overrides:

toString in class Object

Returns:

a string representation of the object.