groovy普通方法、抽象方法、接口、trait

/**
 * Created by Jxy on 2018/12/21 14:07
 * trait关键字
 * 声明trait中的方法和任何常规方法一样
 * trait声明抽象方法需要在实现类中实现
 * 也可以有私有方法 Those methods will not appear in the trait contract interface
 * groovy接口
 * trait也可以实现接口
 */

/*
普通方法
 */
trait FlyingAbility {
    String fly() { "I'm flying!" }
}
class Bird implements FlyingAbility {}
def b = new Bird()
assert b.fly() == "I'm flying!"
println(b.fly())
/*
抽象方法
 */
trait Greetable {
    abstract def name()
    def getName(){
        "hello , ${name()}"
    }
}
class GreetableImpl implements Greetable{

    @Override
    def name() {
        "jser"
    }
}
def p = new GreetableImpl()
println(p.getName())

/*
接口
 */
interface Named {
    String name()
}
trait Greetable1 implements Named {
    String greeting() { "Hello, ${name()}!" }
}
class Person1 implements Greetable1 {
    String name() { 'Bob' }
}

def p1 = new Person1()
assert p1.greeting() == 'Hello, Bob!'
assert p1 instanceof Named
assert p1 instanceof Greetable1

/*
公共字段
避免钻石问题
 */
trait Named1 {
    public String name
}
class Person2 implements Named1 {}
def p2 = new Person2()
p2.Named1__name = 'Bob'
println(p2.Named1__name)