Stream-取得と一般的な方法

package com.itheima.demo02.Stream;

import java.util.*;
import java.util.stream.Stream;

/*
    java.util.stream.Stream Java 8           。（           。）
             ，          ：
        -    Collection       stream       ；
            default Stream stream​()
        - Stream       of          。
            static  Stream of​(T... values)
                     ,             
 */
public class Demo01GetStream {
    public static void main(String[] args) {
        //      Stream 
        List<String> list = new ArrayList<>();
        Stream<String> stream1 = list.stream();
        Set<String> set = new HashSet<>();
        Stream<String> stream2 = set.stream();
        Map<String,String> map = new HashMap<>();
        //   ,     Set   
        Set<String> keySet = map.keySet();
        Stream<String> stream3 = keySet.stream();
        //   ,     Collection   
        Collection<String> values = map.values();
        Stream<String> stream4 = values.stream();
        //     (         entrySet)
        Set<Map.Entry<String, String>> entries = map.entrySet();
        Stream<Map.Entry<String, String>> stream5 = entries.stream();
        //      Stream 
        Stream<Integer> stream6 = Stream.of(1, 2, 3, 4, 5);
        //          
        Integer[] arr = {1,2,3,4,5};
        Stream<Integer> stream7 = Stream.of(arr);
        String[] arr2 = {"a","bb","ccc"};
        Stream<String> stream8 = Stream.of(arr2);
    }
}

package com.itheima.demo03.Stream;

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

/*
      ：      （Stream  ）
        //1.           3       ；         。
        //2.             3  ；         。
        //3.               ；         。
        //4.             2  ；         。
        //5.             ；         。
        //6.       Person  ；         。
        //7.        Person    。
 */
public class Demo02StreamTest {
    public static void main(String[] args) {
        //     
        ArrayList<String> one = new ArrayList<>();
        one.add("    ");
        one.add("   ");
        one.add("   ");
        one.add("   ");
        one.add("   ");
        one.add("  ");
        one.add("  ");
        one.add("   ")；
        Stream<String> oneStream = one.stream().filter(name -> name.length() == 3).limit(3);
        //     
        ArrayList<String> two = new ArrayList<>();
        two.add("    ");
        two.add("   ");
        two.add("   ");
        two.add("   ");
        two.add("      ");
        two.add("   ");
        two.add("   ");
        Stream<String> twoStream = two.stream().filter(name -> name.startsWith(" ")).skip(2);
        Stream.concat(oneStream,twoStream).map(name->new Person(name)).forEach(p-> System.out.println(p));
    }
}