反射——对象之间的复制

    @Test
    void test11() throws Exception {
        Emp emp = new Emp();
        emp.setId("1");
        emp.setName("张三");
        emp.setSex("man");

        User user = new User();

        // 将emp复制到user
        copy(emp,user);

        System.out.println(emp);
        System.out.println(user);
    }

    // 复制属性
    public void copy(Object o1,Object o2) throws IllegalAccessException {
        Class aClass = o1.getClass();
        Class aClass1 = o2.getClass();

        //获取所有属性
        Field[] o1ClassDeclaredFields = aClass.getDeclaredFields();
        Field[] o2ClassDeclaredFields = aClass1.getDeclaredFields();

        //根据name分组，转小写
        Map> collect = Arrays.stream(o1ClassDeclaredFields).collect(Collectors.groupingBy(s->s.getName().toLowerCase()));

        for (Field o2ClassDeclaredField : o2ClassDeclaredFields) {
            // 获取name属性
            String username = o2ClassDeclaredField.getName();
            List fields = collect.get(username.toLowerCase());

            if (!CollectionUtils.isEmpty(fields)){

                Field field = fields.get(0);
                // 开启私有属性
                field.setAccessible(true);
                o2ClassDeclaredField.setAccessible(true);
                o2ClassDeclaredField.set(o2,field.get(o1));
            }
        }
    }