@Documented @Retention(RUNTIME) @Target(TYPE) public @interface TupleConstructor
InheritConstructors
.
It allows you to write classes in this shortened form:
@groovy.transform.TupleConstructor
class Customer {
String first, last
int age
Date since
Collection favItems
}
def c1 = new Customer(first:'Tom', last:'Jones', age:21, since:new Date(), favItems:['Books', 'Games'])
def c2 = new Customer('Tom', 'Jones', 21, new Date(), ['Books', 'Games'])
def c3 = new Customer('Tom', 'Jones')
The @TupleConstructor
annotation instructs the compiler to execute an
AST transformation which adds the necessary constructor method to your class.
A tuple constructor is created with a parameter for each property (and optionally field and super properties). A default value is provided (using Java's default values) for all parameters in the constructor. Groovy's normal conventions then allows any number of parameters to be left off the end of the parameter list including all of the parameters - giving a no-arg constructor which can be used with the map-style naming conventions.
The order of parameters is given by the properties of any super classes with most super first
(if includeSuperProperties
is set) followed by the properties of the class followed
by the fields of the class (if includeFields
is set). Within each grouping the order
is as attributes appear within the respective class.
More examples:
//-------------------------------------------------------------------------- import groovy.transform.TupleConstructor @TupleConstructor() class Person { String name List likes private boolean active = false } def person = new Person('mrhaki', ['Groovy', 'Java']) assert person.name == 'mrhaki' assert person.likes == ['Groovy', 'Java'] person = new Person('mrhaki') assert person.name == 'mrhaki' assert !person.likes
//-------------------------------------------------------------------------- // includeFields in the constructor creation. import groovy.transform.TupleConstructor @TupleConstructor(includeFields=true) class Person { String name List likes private boolean active = false boolean isActivated() { active } } def person = new Person('mrhaki', ['Groovy', 'Java'], true) assert person.name == 'mrhaki' assert person.likes == ['Groovy', 'Java'] assert person.activated
//-------------------------------------------------------------------------- // use force attribute to force creation of constructor // even if we define our own constructors. import groovy.transform.TupleConstructor @TupleConstructor(force=true) class Person { String name List likes private boolean active = false Person(boolean active) { this.active = active } boolean isActivated() { active } } def person = new Person('mrhaki', ['Groovy', 'Java']) assert person.name == 'mrhaki' assert person.likes == ['Groovy', 'Java'] assert !person.activated person = new Person(true) assert person.activated
//-------------------------------------------------------------------------- // include properties and fields from super class. import groovy.transform.TupleConstructor @TupleConstructor(includeFields=true) class Person { String name List likes private boolean active = false boolean isActivated() { active } } @TupleConstructor(callSuper=true, includeSuperProperties=true, includeSuperFields=true) class Student extends Person { List courses } def student = new Student('mrhaki', ['Groovy', 'Java'], true, ['IT']) assert student.name == 'mrhaki' assert student.likes == ['Groovy', 'Java'] assert student.activated assert student.courses == ['IT']
Limitations:
LinkedHashMap
or if there is a single Map, AbstractMap or HashMap property (or field)Modifier and Type | Optional Element | Description |
---|---|---|
boolean |
callSuper |
Should super properties be called within a call to the parent constructor.
|
String[] |
excludes |
List of field and/or property names to exclude from the constructor.
|
boolean |
force |
By default, this annotation becomes a no-op if you provide your own constructor.
|
boolean |
includeFields |
Include fields in the constructor.
|
boolean |
includeProperties |
Include properties in the constructor.
|
String[] |
includes |
List of field and/or property names to include within the constructor.
|
boolean |
includeSuperFields |
Include fields from super classes in the constructor.
|
boolean |
includeSuperProperties |
Include properties from super classes in the constructor.
|
String[] excludes
String[] includes
boolean includeSuperFields
boolean includeSuperProperties