两个对象的一对一关系，比如： 一个丈夫(Husband)对一个妻子(Wife) 把对方的类作为本类的属性，有单向一对一关系，双向一对一关系。 下面展示的是双向一对一关系。
/** 对象的一对一关系 */ public class OneToOneDemo{ public static void main(String[] args){ Husband h = new Husband("小白", '男'); Wife w = new Wife("星星", 23); //关联关系 h.wife = w; w.husband = h; System.out.println("我是：" + h.name + " ，我的妻子是：" + h.wife.name + "她今年" + h.wife.age + "岁了。"); } } /** 丈夫类 */ class Husband{ String name; char sex; Wife wife;//关联妻子类 //getter, setter... public Husband(){} public Husband(String name, char sex){ this.name = name; this.sex = sex; } } /** 妻子类 */ class Wife{ String name; int age; Husband husband;//关联丈夫类 //getter, setter... public Wife(){} public Wife(String name, int age){ this.name = name; this.age = age; } }