Package groovy.transform
Annotation Type Sortable
-
@Retention(RUNTIME) @Target(TYPE) public @interface SortableA class annotation used to make a class Comparable by (potentially) multiple Comparators. As an example, given this class:
The generated Groovy class will:@Sortableclass Person { String first String last Integer born }- implement the
Comparableinterface - have a
compareTomethod based on thefirst,lastandbornproperties (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) - have three
Comparatormethods namedcomparatorByFirst,comparatorByLastandcomparatorByBorn - sort by natural order by default, reversed natural order can be specified
Comparableor@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] - implement the
-
-
Optional Element Summary
Optional Elements Modifier and Type Optional Element Description booleanallNamesWhether to include all fields and/or properties in the comparison algorithm, including those with names that are considered internal.booleanallPropertiesWhether to include all properties (as per the JavaBean spec) in the comparison algorithm.java.lang.String[]excludesProperty names to exclude in the comparison algorithm.java.lang.String[]includesProperty names to include in the comparison algorithm.booleanincludeSuperPropertiesWhether to include super properties in the comparison algorithm.booleanreversedSet to true so that comparator uses reversed natural order.
-
-
-
Element Detail
-
includes
java.lang.String[] includes
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:
- {"<DummyUndefinedMarkerString-DoNotUse>"}
-
-
-
includeSuperProperties
boolean includeSuperProperties
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).- Since:
- 2.5.2
- Default:
- false
-
-
-
allProperties
boolean allProperties
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).- Since:
- 2.5.2
- Default:
- true
-
-