CollectionUtils取交集,并集和差集

import org.apache.commons.collections.CollectionUtils;

 <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <version>${commons-collections.version}</version> </dependency>

public static void main(String[] args) { List<String> listA = new ArrayList<String>(); listA.add("a"); listA.add("b"); listA.add("b"); listA.add("c"); List<String> listB = new ArrayList<String>(); listB.add("a"); listB.add("e"); listB.add("f"); System.out.println("集合A:"+listA); System.out.println("集合B:"+listB); System.out.println("------------------------"); //并集 Collection<String> union = CollectionUtils.union(listA, listB); System.out.println("并集："+union); //交集 Collection<String> intersection = CollectionUtils.intersection(listA, listB); System.out.println("交集："+intersection); //交集的补集 Collection<String> disjunction = CollectionUtils.disjunction(listA, listB); System.out.println("交集的补集 ："+disjunction); //差集(集合相减) Collection<String> subtract = CollectionUtils.subtract(listA, listB); System.out.println("差集(集合相减) ："+subtract); }

集合A:[a, b, b, c] 集合B:[a, e, f] ------------------------ 并集：[a, b, b, c, e, f] 交集：[a] 交集的补集 ：[b, b, c, e, f] 差集(集合相减) ：[b, b, c]