java8拼接两个list_java8俩个list

packagecom.sly.uploadfile.base;importjava.util.ArrayList;importjava.util.List;import staticjava.util.stream.Collectors.toList;/*** Created by fmgao on 2020/5/22.*/

public classJava8ListCalc {public static voidmain(String[] args) {

List list1 = new ArrayList();

list1.add("1");

list1.add("2");

list1.add("3");

list1.add("5");

list1.add("6");

List list2 = new ArrayList();

list2.add("2");

list2.add("3");

list2.add("7");

list2.add("8");//交集

List intersection = list1.stream().filter(item ->list2.contains(item)).collect(toList());

System.out.println("---交集 intersection---");

intersection.parallelStream().forEach(System.out::println);//差集 (list1 - list2)

List reduce1 = list1.stream().filter(item -> !list2.contains(item)).collect(toList());

System.out.println("---差集 reduce1 (list1 - list2)---");

reduce1.parallelStream().forEach(System.out::println);//差集 (list2 - list1)

List reduce2 = list2.stream().filter(item -> !list1.contains(item)).collect(toList());

System.out.println("---差集 reduce2 (list2 - list1)---");

reduce2.parallelStream().forEach(System.out::println);//并集

List listAll =list1.parallelStream().collect(toList());

List listAll2 =list2.parallelStream().collect(toList());

listAll.addAll(listAll2);

System.out.println("---并集 listAll---");

listAll.parallelStream().forEachOrdered(System.out::println);//去重并集

List listAllDistinct =listAll.stream().distinct().collect(toList());

System.out.println("---得到去重并集 listAllDistinct---");

listAllDistinct.parallelStream().forEachOrdered(System.out::println);

System.out.println("---原来的List1---");

list1.parallelStream().forEachOrdered(System.out::println);

System.out.println("---原来的List2---");

list2.parallelStream().forEachOrdered(System.out::println);

}

}