A class annotation used to make a class Comparable by (potentially) multiple Comparators. As an example, given this class:
@Sortable class Person {
String first
String last
Integer born
}
The generated Groovy class will:
Comparable interfacecompareTo method based on the first,
last and born properties (priority ordering will be according
to the ordering of property definition, highest first, unless 'includes' is used; in which case,
priority will be according to the order given in the includes list)Comparator methods named comparatorByFirst,
comparatorByLast and comparatorByBornComparable or @Sortable.
More examples:
//--------------------------------------------------------------------------
import groovy.transform.Sortable
import groovy.transform.ToString
@Sortable
@ToString
class Course {
// Order of properties determines priority when sorting
String title
Date beginDate
Integer maxAttendees // int doesn't implement Comparable, so use Integer
}
final Course groovy = new Course(
title: 'Groovy', beginDate: new Date() + 7, maxAttendees: 40)
final Course groovy2 = new Course(
title: 'Groovy', beginDate: new Date() + 2, maxAttendees: 50)
final Course grails = new Course(
title: 'Grails', beginDate: new Date() + 1, maxAttendees: 20)
final List<Course> courses = [groovy, groovy2, grails]
assert courses.last().title == 'Grails'
// Use toSorted() method to sort
final List<Course> sorted = courses.toSorted()
assert sorted.first().title == 'Grails'
assert sorted.last().title == 'Groovy'
assert sorted.maxAttendees == [20, 50, 40]
//--------------------------------------------------------------------------
// Order of fields for includes determines priority when sorting
import groovy.transform.Sortable
import groovy.transform.ToString
@Sortable(includes = ['title', 'maxAttendees'])
// Or @Sortable(excludes = ['beginDate'])
@ToString
class Course {
String title
Date beginDate
Integer maxAttendees
}
final Course groovy = new Course(
title: 'Groovy', beginDate: new Date() + 7, maxAttendees: 40)
final Course groovy2 = new Course(
title: 'Groovy', beginDate: new Date() + 2, maxAttendees: 50)
final Course grails = new Course(
title: 'Grails', beginDate: new Date() + 1, maxAttendees: 20)
final List<Course> courses = [groovy, groovy2, grails]
// Use toSorted() method to sort
final List<Course> sorted = courses.toSorted()
assert sorted.first().title == 'Grails'
assert sorted.last().title == 'Groovy'
assert sorted.maxAttendees == [20, 40, 50]
//--------------------------------------------------------------------------
// Static methods to create comparators.
final Comparator byMaxAttendees = Course.comparatorByMaxAttendees()
final List<Course> sortedByMaxAttendees = courses.sort(false, byMaxAttendees)
assert sortedByMaxAttendees.maxAttendees == [20, 40, 50]
// beginDate is not used for sorting
assert sortedByMaxAttendees[2].beginDate < sortedByMaxAttendees[1].beginDate
assert Course.declaredMethods.name.findAll { it.startsWith('comparatorBy') }.toSorted() == ['comparatorByMaxAttendees', 'comparatorByTitle']
//--------------------------------------------------------------------------
// Sorting by max attendees using reversed order
import groovy.transform.Sortable
import groovy.transform.ToString
@Sortable(includes = ['points'], reversed = true)
@ToString
class LeaderBoardEntry {
String team
int points
}
final LeaderBoardEntry teamA = new LeaderBoardEntry(team: "Team A", points: 30)
final LeaderBoardEntry teamB = new LeaderBoardEntry(team: "Team B", points: 80)
final LeaderBoardEntry teamC = new LeaderBoardEntry(team: "Team C", points: 50)
final List<LeaderBoardEntry> leaderBoard = [teamA, teamB, teamC].toSorted()
assert leaderBoard.first().team == 'Team B'
assert leaderBoard.last().team == 'Team A'
assert leaderBoard.points == [80, 50, 30]
| Type | Name and Description |
|---|---|
boolean |
allNamesWhether to include all fields and/or properties in the comparison algorithm, including those with names that are considered internal. |
boolean |
allPropertiesWhether to include all properties (as per the JavaBean spec) in the comparison algorithm. |
String[] |
excludesProperty names to exclude in the comparison algorithm. |
boolean |
includeSuperPropertiesWhether to include super properties in the comparison algorithm. |
String[] |
includesProperty names to include in the comparison algorithm. |
boolean |
reversedSet to true so that comparator uses reversed natural order. |
Whether to include all fields and/or properties in the comparison algorithm, including those with names that are considered internal. @default false
Whether to include all properties (as per the JavaBean spec) in the comparison algorithm. Groovy recognizes any field-like definitions with no explicit visibility as property definitions and always includes them in the comparison algorithm. Groovy also treats any explicitly created getXxx() or isYyy() methods as property getters as per the JavaBean specification. Set this flag to false explicitly exclude such properties. JavaBean properties come after any Groovy properties for a given class (unless 'includes' is used to determine the order). @default true
Property names to exclude in the comparison algorithm. Must not be used if 'includes' is used. @default {}
Whether to include super properties in the comparison algorithm. Groovy properties and potentially JavaBean properties (in that order) from superclasses come before the members from a subclass (unless 'includes' is used to determine the order). @default false
Property names to include in the comparison algorithm. Must not be used if 'excludes' is used. The default value is a special marker value indicating that no includes are defined; all properties are included if 'includes' remains undefined and 'excludes' is explicitly or implicitly an empty list. @default {Undefined.STRING}
Set to true so that comparator uses reversed natural order. @default false