import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

public class ListUntil {

public static void main(String[] args) {

ArrayList arraylist1 = new ArrayList();

ArrayList arraylist2 = new ArrayList();

arraylist1.add(1);

arraylist1.add(2);

arraylist1.add(3);

arraylist2.add(3);

arraylist2.add(4);

List list=ObjectArrayListIntersections(arraylist1,arraylist2);

System.out.println("result" + list);

}

// 兩個(gè)List集合集求差集

public static ArrayList ObjectArrayListDifference(ArrayList arraylist1, ArrayList arraylist2) {

arraylist1.removeAll(arraylist2);

return arraylist1;

}

// 兩個(gè)List集合集求并集

public static List ObjectArrayListUnion(ArrayList arraylist1, ArrayList arraylist2) {

List arraylist = new ArrayList();

arraylist.addAll(arraylist1);

arraylist.addAll(arraylist2);

arraylist = new ArrayList(new HashSet(arraylist));

return arraylist;

}

// 兩個(gè)List集合集求交集

public static ArrayList ObjectArrayListIntersections(ArrayList arraylist1,

ArrayList arraylist2) {

arraylist1.retainAll(arraylist2);

return arraylist1;

}

}

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JAVA求字符串?dāng)?shù)組交集、并集和差集

http://blog.sina.com.cn/s/blog_4934a04a0100fqmf.html

Java中取兩個(gè)集合的并集、交集和差集

http://suko.iteye.com/blog/2053654

Setset1 = new HashSet<>();

Setset2 = new HashSet<>();

set1.add("a");

set1.add("b");

set1.add("c");

set2.add("c");

set2.add("b");

set2.add("e");

// 交集

// set1.retainAll(set2);

// System.out.println("交集是 "+set1);

// 并集

// set1.addAll(set2);

//System.out.println("并集是 " + set1);

// 差集

set1.removeAll(set2);

System.out.println("差集是 " + set1);