比较两个list，返回多余部分和删除部分

import java.util.ArrayList;
import java.util.List;
 
public class CompareTwoListUtil {
    public static void getList(List<Long> oldGroupIdList, List<Long> newGroupIdList, List<Long> addList, List<Long> delList) {
        if(newGroupIdList != null && !newGroupIdList.isEmpty()) {
            //以aList为准，aList比bList多余的部分添加,少的部分删除,相同的部分更新
            List<Long> updateList1 = new ArrayList();
            List<Long> updateList2 = new ArrayList();
 
            //找出需要添加的部分和共同的部分
            for (int i = 0; i < newGroupIdList.size(); i++) {
                boolean isAdd = true;
                Long newGroupId = newGroupIdList.get(i);
                for (int j = 0; j < oldGroupIdList.size(); j++) {
                    Long bTemp = oldGroupIdList.get(j);
                    if (newGroupId.equals(bTemp)) {
                        updateList1.add(newGroupId);
                        isAdd = false;
                    }
                }
                if (isAdd) {
                    addList.add(newGroupId);
                }
            }
            //找出需要删除的部分和共同的部分
            for (int i = 0; i < oldGroupIdList.size(); i++) {
                boolean isDel = true;
                Long bTemp = oldGroupIdList.get(i);
                for (int j = 0; j < newGroupIdList.size(); j++) {
                    Long aTemp = newGroupIdList.get(j);
                    if (aTemp.equals(bTemp)) {
                        updateList2.add(aTemp);
                        isDel = false;
                    }
                }
                if (isDel) {
                    delList.add(bTemp);
                }
            }
        }else {
            if(oldGroupIdList != null && !oldGroupIdList.isEmpty()) {
                for (Long aLong : oldGroupIdList) {
                    delList.add(aLong);
                }
            }
        }
    }
}