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A GroovyBean is a class with simple properties — Groovy auto-generates getters and setters. Like Lombok in Java, but built in.

class Person {
    String name
    int age
    boolean active = true   // default value
}

def p = new Person(name: "Ada", age: 36)   // constructor takes named args
p.name = "Ada Lovelace"                     // setter — under the hood: p.setName(...)
println p.name                               // getter — under the hood: p.getName()

The field declaration is short — Groovy generates the getter/setter, the no-arg constructor, the named-arg constructor, all behind the scenes.

@Canonical auto-generates equals, hashCode, toString, and a positional constructor:

import groovy.transform.Canonical

@Canonical
class Point {
    int x
    int y
}

def p1 = new Point(3, 4)        // positional — works because of @Canonical
println p1                       // "Point(3, 4)"
p1 == new Point(3, 4)            // true

@Immutable — like @Canonical but freezes the object:

@Immutable
class Point { int x, int y }

@ToString(includeNames=true) — controls toString format:

@ToString(includeNames=true)
class User { String name; int age }
// User(name:Ada, age:36)

All of these are AST transformations — applied at compile time, no runtime cost.