Java8 利用Lambda处理List集合

List<User> list = new ArrayList<User>();
User user1 = new User("第一位","用户1");
list.add(user1);
User user2 = new User("第二位","用户2");
list.add(user2);
User user3 = new User("第三位","用户3");
list.add(user3);
List<String> tableNames=list.stream().map(User::getMessage).collect(Collectors.toList());
System.out.println("输出第一个："+tableNames);
List<String> orders=list.stream().map(User::getOrder).collect(Collectors.toList());
System.out.println(orders)