[Java知识库]java 学习之Stream流

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package cn.edu.ncu.xjx.Demo09Stream;

import java.util.ArrayList;

public class Demo01StreamTest {
    public static void main(String[] args) {
        ArrayList<String> one = new ArrayList<>();
        one.add("迪丽热巴");
        one.add("宋远桥");
        one.add("苏星河");
        one.add("石破天");
        one.add("石中玉");
        one.add("老子");
        one.add("庄子");
        one.add("洪七公");
        ArrayList<String> one1 = new ArrayList<>();
        for (String s : one) {
            if (s.length()==3){
                one1.add(s);
            }
        }

        ArrayList<String> one2 = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            one2.add(one1.get(i));
        }



        ArrayList<String> two = new ArrayList<>();
        two.add("古力娜扎");
        two.add("张无忌");
        two.add("赵丽颖");
        two.add("张三丰");
        two.add("尼古拉斯赵四");
        two.add("张天爱");
        two.add("张二狗");


        ArrayList<String> two1 = new ArrayList<>();
        for (String s : two) {
            if (s.startsWith("张")){
                two1.add(s);
            }
        }
        ArrayList<String> two2 = new ArrayList<>();
        for (int i = 2; i < two1.size(); i++) {
            two2.add(two1.get(i));
        }

        ArrayList<String> all = new ArrayList<>();
        all.addAll(one2);
        all.addAll(two2);
        ArrayList<Person> list = new ArrayList<>();

        for (String s : all) {
            list.add(new Person(s));
        }

        for (Person person : list) {
            System.out.println(person);
        }
    }
}

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package cn.edu.ncu.xjx.Demo09Stream;

import java.util.ArrayList;
import java.util.stream.Stream;

public class Demo02StreamTest {
    public static void main(String[] args) {
        ArrayList<String> one = new ArrayList<>();
        one.add("迪丽热巴");
        one.add("宋远桥");
        one.add("苏星河");
        one.add("石破天");
        one.add("石中玉");
        one.add("老子");
        one.add("庄子");
        one.add("洪七公");
        Stream<String> oneStream = one.stream().filter(name -> name.length() == 3).limit(3);



        ArrayList<String> two = new ArrayList<>();
        two.add("古力娜扎");
        two.add("张无忌");
        two.add("赵丽颖");
        two.add("张三丰");
        two.add("尼古拉斯赵四");
        two.add("张天爱");
        two.add("张二狗");

        Stream<String> twoStream = two.stream().filter(name -> name.startsWith("张")).skip(2);
        Stream.concat(oneStream,twoStream).map(name->new Person(name)).forEach(System.out::println);
    }
}

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