CollectionUtils取交集,并集和差集

Dear 丶 2023-03-01 09:45 15阅读 0赞

## CollectionUtils取交集,并集和差集 ##

**先看交集，并集和差集**  
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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);
        }

**结果：**

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]

Maven依赖

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

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