java擷取兩個list集合的并集、交集、交集的補集、差集

1、maven包依賴

<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-collections4</artifactId>
	<version>4.1</version>
</dependency>           

2、具體代碼

public class demo {

	//兩個集合也可以是對象集合
    public static void main(String[] args) {
        List<String> list1 = new ArrayList<String>();
        List<String> list2 = new ArrayList<String>();

        String String1 = new String("1");
        String String2 = new String("2");
        String String3 = new String("1");
        String String4 = new String("4");

        list1.add(String1);
        list1.add(String2);

        list2.add(String3);
        list2.add(String4);

        List<String> union = getUnion(list1,list2);
        System.out.println("并集："+union);

        List<String> intersection = getIntersection(list1,list2);
        System.out.println("交集："+intersection);

        List<String> disjunction = getDisjunction(list1,list2);
        System.out.println("交集的補集："+disjunction);

        List<String> subtract = getSubtract(union,list1);
        System.out.println("差集："+subtract);
    }

    //擷取兩個集合并集（自動去重）
    public static List<String> getUnion(List<String> list1, List<String> list2){
        List<String> union = (List<String>) CollectionUtils.union(list1, list2);
        return union;
    }

    //擷取兩個集合交集
    public static List<String> getIntersection(List<String> list1,List<String> list2){
        List<String> intersection = (List<String>)CollectionUtils.intersection(list1, list2);
        return intersection;
    }
    //擷取兩個集合交集的補集 即 list1 + list2 - 交集
    public static List<String> getDisjunction(List<String> list1,List<String> list2){
        List<String> disjunction = (List<String>)CollectionUtils.disjunction(list1, list2);
        return disjunction;
    }

    //擷取兩個集合的差集 list1 - 交集
    public static List<String> getSubtract(List<String> list1,List<String> list2){
        List<String> subtract = (List<String>)CollectionUtils.subtract(list1, list2);
        return subtract;
    }

}           

運作結果：