cotterpin

Functional Fluent Java Object Graph Builder

Building a Java object graph, particularly of Java beans, is annoying and verbose. Fluent builders are better, but require the creation or generation of custom code for the purpose. Cotterpin provides a fluent interface to emulate a similar experience using Java 8 functors.

simple property

Cotterpin.build(Franchise::new)
    .child("Psycho").onto(Franchise::setName)
.get()

Shorthand version (using static import):

$(Franchise::new)
    .$$("Psycho").onto(Franchise::setName)
.get()

collection element

Cotterpin.build(Franchise::new)
    .child("Evil Dead").onto(Franchise::setName)
    .child(Character::new)
        .child(CharacterType.UNDEAD).onto(Character::setType)
        .child("Book").addTo(Character::getWeaknesses, ifNull(Character::setWeaknesses, LinkedHashSet<String>::new))
        .child("Chainsaw").addTo(Character::getWeaknesses)
        .child("Boomstick").addTo(Character::getWeaknesses)
    .into(Franchise::getCharacters, ifNull(Franchise::setCharacters, TreeMap::new)).at("Henrietta")
.get()

Shorthand version:

$(Franchise::new)
    .$$("Evil Dead").onto(Franchise::setName)
    .$$(Character::new)
        .$$(CharacterType.UNDEAD).onto(Character::setType)
        .$$("Book").addTo(Character::getWeaknesses, ifNull(Character::setWeaknesses, LinkedHashSet<String>::new))
        .$$("Chainsaw").addTo(Character::getWeaknesses)
        .$$("Boomstick").addTo(Character::getWeaknesses)
    .into(Franchise::getCharacters, ifNull(Franchise::setCharacters, TreeMap::new)).at("Henrietta")
.get()

map entry

Cotterpin.build(Franchise::new)
    .child("Nightmare on Elm Street").onto(Franchise::setName)
    .child(Character::new)
        .child(CharacterType.GHOST).onto(Character::setType)
    .into(Franchise::getCharacters, ifNull(Franchise::setCharacters, TreeMap::new)).at("Freddy Krueger")
.get()

Shorthand version:

$(Franchise::new)
    .$$("Nightmare on Elm Street").onto(Franchise::setName)
    .$$(Character::new)
        .$$(CharacterType.GHOST).onto(Character::setType)
    .into(Franchise::getCharacters, ifNull(Franchise::setCharacters, TreeMap::new)).at("Freddy Krueger")
.get()

raw typed component

Cotterpin.build(Franchise::new)
    .child("Halloween").onto(Franchise::setName)
    .mutate(Franchise.Info.class)
        .child(Year.of(1978)).onto(Franchise.Info::setOriginated)
    .onto(Franchise::getInfo)
.get()

Shorthand version:

$(Franchise::new)
    .$$("Halloween").onto(Franchise::setName)
    .__(Franchise.Info.class)
        .$$(Year.of(1978)).onto(Franchise.Info::setOriginated)
    .onto(Franchise::getInfo)
.get()

fully typed component

Using org.apache.commons.lang3.Typed:

Cotterpin.build(Franchise::new)
    .child("Halloween").onto(Franchise::setName)
    .mutate(new TypeLiteral<Franchise.Info>() {})
        .child(Year.of(1978)).onto(Franchise.Info::setOriginated)
    .onto(Franchise::getInfo)
.get()

Shorthand version:

$(Franchise::new)
    .$$("Halloween").onto(Franchise::setName)
    .__(new TypeLiteral<Franchise.Info>() {})
        .$$(Year.of(1978)).onto(Franchise.Info::setOriginated)
    .onto(Franchise::getInfo)
.get()

cast-less null child:

Cotterpin.build(Franchise::new)
    .nul(String.class).onto(Franchise::setName)
.get()

root Collection

Cotterpin.buildCollection(() -> new ArrayList<Character>())
    .element(Character::new)
        .child(CharacterType.ALIEN).onto(Character::setType)
    .add()
    .element(Character::new)
        .child(CharacterType.DEMON).onto(Character::setType)
    .add()
    .element(Character::new)
        .child(CharacterType.GHOST).onto(Character::setType)
    .add()
.get()

Shorthand version:

c$(() -> new ArrayList<Character>())
    .$$(Character::new)
        .$$(CharacterType.ALIEN).onto(Character::setType)
    .add()
    .$$(Character::new)
        .$$(CharacterType.DEMON).onto(Character::setType)
    .add()
    .$$(Character::new)
        .$$(CharacterType.GHOST).onto(Character::setType)
    .add()
.get()

root Map

Cotterpin.buildMap(() -> new LinkedHashMap<String, Character>())
    .value(Character::new)
        .child(CharacterType.GOLEM).onto(Character::setType)
    .at("Blade")
    .value(Character::new)
        .child(CharacterType.GOLEM).onto(Character::setType)
    .at("Pinhead")
    .value(Character::new)
        .child(CharacterType.GOLEM).onto(Character::setType)
    .at("Jester")
.get()

Shorthand version:

m$(() -> new LinkedHashMap<String, Character>())
    .$$(Character::new)
        .$$(CharacterType.GOLEM).onto(Character::setType)
    .at("Blade")
    .$$(Character::new)
        .$$(CharacterType.GOLEM).onto(Character::setType)
    .at("Pinhead")
    .$$(Character::new)
        .$$(CharacterType.GOLEM).onto(Character::setType)
    .at("Jester")
.get()