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 16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;
        }
    }