Predicate that compares the input object with the one stored in the predicate using a comparator.
In addition, the comparator result can be evaluated in accordance to a supplied criterion value.
In order to demonstrate the use of the predicate, the following variables are declared:
Integer ONE = Integer.valueOf(1);
Integer TWO = Integer.valueOf(2);
Comparator comparator = new Comparator() {
public int compare(Object first, Object second) {
return ((Integer) second) - ((Integer) first);
}
};
Using the declared variables, the ComparatorPredicate
can be used used in the
following way:
ComparatorPredicate.comparatorPredicate(ONE, comparator).evaluate(TWO);
The input variable TWO
in compared to the stored variable ONE
using
the supplied comparator
. This is the default usage of the predicate and will return
true
if the underlying comparator returns 0
. In addition to the default
usage of the predicate, it is possible to evaluate the comparator's result in several ways. The
following
Criterion enumeration values are provided by the predicate:
- EQUAL
- GREATER
- GREATER_OR_EQUAL
- LESS
- LESS_OR_EQUAL
The following examples demonstrates how these constants can be used in order to manipulate the
evaluation of a comparator result.
ComparatorPredicate.comparatorPredicate(ONE, comparator,ComparatorPredicate.Criterion.GREATER).evaluate(TWO);
The input variable TWO is compared to the stored variable ONE using the supplied comparator
using the GREATER
evaluation criterion constant. This instructs the predicate to
return true
if the comparator returns a value greater than 0
.