java 连缀用法

        Apple apple = new Apple()
                .setColor("Green")
                .setWeight(12.3f);

public class Apple {

    private String color;
    public Apple setColor(String color) {
        this.color = color;
        return this;
        }
    public String getColor() {return color;}

    private float weight;
    public Apple setWeight(float weight) {
        this.weight = weight;
        return this;
        }
    public float getWeight() {return weight;}

}