java8新特性-Stream概述

public class App {
    public static void main(String[] args) {
        //1.添加测试数据
        List<String> accounts = new ArrayList<>();
        accounts.add("tom");
        accounts.add("jerry");
        accounts.add("beita");
        //1.1 业务要求：长度大于等于5的有效账号
        for (String account : accounts) {
            if (account.length() >= 5) {
                System.out.println("有效账号:" + account);
            }
        }
        //1.2 通过迭代方式进行操作
        Iterator<String> iterator = accounts.iterator();
        while (iterator.hasNext()) {
            String account = iterator.next();
            if (account.length() >= 5) {
                System.out.println("有效账号:" + account);
            }
        }
        //1.3 stream结合lambda表达式进行处理
        List<String> vaildAccounts = accounts.stream().filter(s -> s.length() >= 5).collect(Collectors.toList());
        System.out.println(vaildAccounts);
    }
}