java8操作两个集合List

【java8操作两个集合List】public static void main(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);

}

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