java8 list、map遍歷以及反射

     //新建list

        List<User> userList = new ArrayList<>();
        User user = new User();
        user.setId("user-01");
        user.setName("張三");
        user.setAge(18);

        User user1 = new User();
        user1.setId("user-02");
        user1.setName("李四");
        user1.setAge(19);


        User user2 = new User();
        user2.setId("user-03");
        user2.setName("王五");
        user2.setAge(28);

        userList.add(user);
        userList.add(user1);
        userList.add(user2);
        
        //遍歷list
        userList.forEach(s->{
            System.out.println("被遍歷的list"+s.getName());
        });

        //list去重復

        userList.stream().distinct().collect(Collector.toList());         

        //通過stream把list轉為map
        Map<String, User> collect = userList.stream().collect(Collectors.toMap(User::getId, Function.identity(), (o1, o2) -> o2));
        System.out.println(collect.toString());


        //利用@Builder 注解一次性給對象賦值
        User userBuild =User.builder().age(1).Id("build-01").name("buildName").build();

        System.out.println(userBuild.toString());

        //遍歷map
        collect.forEach((k,v)->{
            if(k.equals("user-01")){
                v.setAge(100);
            }
        });

        System.out.println("遍歷之后的"+collect.toString());

        //反射
        StringBuffer saveIdBuffer = new StringBuffer();

        collect.forEach((k,v)->{
            try {
                 //capitalize 首字母大寫
                Method  method = v.getClass().getMethod("get" + StringUtils.capitalize("id"));
                try {
                    saveIdBuffer.append(method.invoke(v));
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                }
                
            } catch (NoSuchMethodException e) {
                e.printStackTrace();
            }

        });

        System.out.println("通過反射得到的所有id"+saveIdBuffer);