Annotation Type TupleConstructor


  • @Documented
    @Retention(RUNTIME)
    @Target(TYPE)
    public @interface TupleConstructor
    Class annotation used to assist in the creation of tuple constructors in classes. Do not use with 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:

    • Groovy's normal map-style naming conventions will not be available if the first property (or field) has type LinkedHashMap or if there is a single Map, AbstractMap or HashMap property (or field)
    Since:
    1.8.0
    Author:
    Paul King
    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element Description
      boolean callSuper
      Should super properties be called within a call to the parent constructor.
      java.lang.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.
      java.lang.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.
    • Element Detail

      • excludes

        java.lang.String[] excludes
        List of field and/or property names to exclude from the constructor. Must not be used if 'includes' is used. For convenience, a String with comma separated names can be used in addition to an array (using Groovy's literal list notation) of String values.
        Default:
        {}
      • includes

        java.lang.String[] includes
        List of field and/or property names to include within the constructor. Must not be used if 'excludes' is used. For convenience, a String with comma separated names can be used in addition to an array (using Groovy's literal list notation) of String values.
        Default:
        {}
      • includeFields

        boolean includeFields
        Include fields in the constructor.
        Default:
        false
      • includeProperties

        boolean includeProperties
        Include properties in the constructor.
        Default:
        true
      • includeSuperFields

        boolean includeSuperFields
        Include fields from super classes in the constructor.
        Default:
        false
      • includeSuperProperties

        boolean includeSuperProperties
        Include properties from super classes in the constructor.
        Default:
        false
      • callSuper

        boolean callSuper
        Should super properties be called within a call to the parent constructor. rather than set as properties
        Default:
        false
      • force

        boolean force
        By default, this annotation becomes a no-op if you provide your own constructor. By setting force=true then the tuple constructor(s) will be added regardless of whether existing constructors exist. It is up to you to avoid creating duplicate constructors.
        Default:
        false