java中两个list集合取并集，交集和差集的方法-蒲公英云

java中两个list集合取并集，交集和差集的方法

心已赠人 2023-03-12 12:11 86阅读 0赞

引入jar包 commons-collections

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.1</version>
</dependency>
public class Test { 
    public static void main(String[] args) { 
        List<Student> list1 = new ArrayList<Student>();
        List<Student> list2 = new ArrayList<Student>();
        Student student1 = new Student().setId("1").setName("张三");
        Student student2 = new Student().setId("2").setName("李四");
        Student student3 = new Student().setId("2").setName("李四");
        Student student4 = new Student().setId("3").setName("王五");
        list1.add(student1);
        list1.add(student2);
        list2.add(student3);
        list2.add(student4);
        List<Student> union = getUnion(list1,list2);
        System.out.println("并集："+union);
        List<Student> intersection = getIntersection(list1,list2);
        System.out.println("交集："+intersection);
        List<Student> disjunction = getDisjunction(list1,list2);
        System.out.println("交集的补集："+disjunction);
        List<Student> subtract = getSubtract(list1,list2);
        System.out.println("差集："+subtract);
    }
    //获取两个集合并集（自动去重）
    public static List<Student> getUnion(List<Student> list1,List<Student> list2){ 
        List<Student> union = (List<Student>)CollectionUtils.union(list1, list2);
        return union;
    }
    //获取两个集合交集
    public static List<Student> getIntersection(List<Student> list1,List<Student> list2){ 
        List<Student> intersection = (List<Student>)CollectionUtils.intersection(list1, list2);
        return intersection;
    }
    //获取两个集合交集的补集 即 list1 + list2 - 交集
    public static List<Student> getDisjunction(List<Student> list1,List<Student> list2){ 
        List<Student> disjunction = (List<Student>)CollectionUtils.disjunction(list1, list2);
        return disjunction;
    }
    //获取两个集合的差集 list1 - 交集
    public static List<Student> getSubtract(List<Student> list1,List<Student> list2){ 
        List<Student> subtract = (List<Student>)CollectionUtils.subtract(list1, list2);
        return subtract;
    }
}