Introdution

Java8 introduces a lot of new features, incluidng the most exciting one, lambda. In this project, i try to implement a generic builder by Monad pattern. However, after implementing, i found monad pattern is not quite suitable for builder. Anyway, I gave up the map and flatMap in monad while i use nested initiation instead.

Creating an Object With Initialization block

Course course = Builder.of(new Course(), (c) -> {
    c.setName("Functional Language");
    c.setRating(95);
}).get();

Building an Object With Fluent Style.

Course course = Builder.of(new Course())
    .set(Course::setName, "Functional Language")
    .set(Course::setRating, 95)
    .get();

Nested Initialization

Course course = Builder.of(new Course())
    .set(Course::setName, "Functional Language")
    .set(Course::setRating, 95)
    .set(Course::setTeacher, new User(), (teacher, builder)-> {
        teacher.setUserId(1);
        teacher.setName("pop");
    })
    .get();

Initiating a List Member

Course course = Builder.of(new Course())
    .set(Course::setName, "Functionl Language")
    .set(Course::setRating, 95)
    .setList(Course::setStudents, new ArrayList<>(), (students, listBuilder) -> {
        listBuilder
        .add(new User(), (student, b) -> {
            student.setUserId(2);
            student.setName("foo");
        })
        .add(new User(), (student, b) -> {
            student.setUserId(3);
            student.setName("bar");
        });
    })
    .get(); 

Initiating a Map Member

Course course = Builder.of(new Course())
    .set(Course::setName, "Functional Language")
    .setMap(Course::setMeta, new HashMap<>(), (meta, mapBuilder) -> {
        mapBuilder
        .put("foo", "bar")
        .put("abc", "xyz");
    })
    .get();