用java写给出两个整数集合A、B，求出他们的交集、并集以及B在A中的余集的程序

import java.util.HashSet;
import java.util.Set;

public class SetOperations {

    public static Set<Integer> intersection(Set<Integer> setA, Set<Integer> setB) {
        Set<Integer> intersectionSet = new HashSet<>(setA);
        intersectionSet.retainAll(setB);
        return intersectionSet;
    }

    public static Set<Integer> union(Set<Integer> setA, Set<Integer> setB) {
        Set<Integer> unionSet = new HashSet<>(setA);
        unionSet.addAll(setB);
        return unionSet;
    }

    public static Set<Integer> complement(Set<Integer> setA, Set<Integer> setB) {
        Set<Integer> complementSet = new HashSet<>(setA);
        complementSet.removeAll(setB);
        return complementSet;
    }

    public static void main(String[] args) {
        Set<Integer> setA = new HashSet<>();
        setA.add(1);
        setA.add(2);
        setA.add(3);

        Set<Integer> setB = new HashSet<>();
        setB.add(2);
        setB.add(3);
        setB.add(4);

        // intersection
        Set<Integer> intersection = intersection(setA, setB);
        System.out.println("Intersection: " + intersection);

        // union
        Set<Integer> union = union(setA, setB);
        System.out.println("Union: " + union);

        // complement
        Set<Integer> complement = complement(setA, setB);
        System.out.println("Complement of B in A: " + complement);
    }
}

输出结果为：

Intersection: [2, 3]
Union: [1, 2, 3, 4]
Complement of B in A: [1]