Jpa Specification如何实现and和or同时使用查询

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
 
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import java.util.ArrayList;
import java.util.List;
 
@Service
@Transactional
public class UserServiceImpl implements UserService {
    @Autowired
    private RongUserRepository rongUserRepository;
     //FriendNumResult  自定的返回类型
    //FriendNumParam  自定义的封装参数的类型
    //RongUser  实体类型
    @Override
    public FriendNumResult friendNum(FriendNumParam friendNumParam) {
        FriendNumResult friendNumResult=new FriendNumResult();
 
        Specification<RongUser> specification = new Specification<RongUser>(){
 
            @Override
            public Predicate toPredicate(Root<RongUser> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                //封装and语句
                List<Predicate> listAnd = new ArrayList<Predicate>();
                //这里是hql，所以root.get(),方法里面必须是对应的实体属性
                listAnd.add(criteriaBuilder.equal(root.get("perLevel").as(Integer.class), friendNumParam.getPerLevel()));
                Predicate[] array_and=new Predicate[listAnd.size()];
                Predicate Pre_And = criteriaBuilder.and(listAnd.toArray(array_and));
 
                //封装or语句
                List<Predicate> listOr = new ArrayList<Predicate>();
                listOr.add(criteriaBuilder.equal(root.get("fId").as(Integer.class), friendNumParam.getUid()));
                listOr.add(criteriaBuilder.equal(root.get("fId2").as(Integer.class), friendNumParam.getUid()));
                Predicate[] arrayOr = new Predicate[listOr.size()];
                Predicate Pre_Or = criteriaBuilder.or(listOr.toArray(arrayOr));
 
                return criteriaQuery.where(Pre_And,Pre_Or).getRestriction();
                //单独使用  and 或者  or 时 返回
                //return criteriaBuilder.and(list.toArray());
            }
        };
        long num=this.rongUserRepository.count(specification);
        friendNumResult.setFriendNum(Integer.valueOf((int)num));
        return friendNumResult;
    }
}

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
//RongUser  自己的实体类型
public interface RongUserRepository extends JpaRepository<RongUser,Integer> , JpaSpecificationExecutor<RongUser> {
}

SELECT *
FROM   table
WHERE  1 = 1
   if (a == 1)
        AND table.column1 = a
   if (b != null)
        AND table.column2 = b
   if (cList != null && cList.size() > 0)
        AND table.column3 IN cList
   if (d == 2 || dd == 2)
        AND (table.column4 = d OR table.column5 = dd)

@Data
@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    /**
     * 用户名
     */
    private String username;
    /**
     * 年龄
     */
    private Integer age;
    /**
     * 生日
     */
    private Date birthDay;
    /**
     * 删除标识； 0 - 未删除，1 - 已删除
     */
    private Integer deleteFlag;
}

@Repository
public interface UserDAO extends JpaRepository<User, Long> {
    /**
     * 其实，这个功能一般用作 list 接口使用，一般结合分页查询使用。这里，我不做介绍，看情况要不要后期加上教程
     */
    List<User> findAll(Specification<User> querySpec);
}

@Data
public class UserDTO {
    /**
     * 用户名，用于模糊搜索
     */
    private String username;
    /**
     * 用户ID，用于 In 查询
     */
    private List<String> userIdList;
    /**
     * 用户年龄，用于 OR In 查询
     */
    private List<Integer> ageList;
    /**
     * 生日，开始
     */
    @JsonFormat(pattern = "yyyy-MM-dd", locale = "zh", timezone = "GMT+8")
    private Date birthDayBegin;
    /**
     * 生日，结束
     */
    @JsonFormat(pattern = "yyyy-MM-dd", locale = "zh", timezone = "GMT+8")
    private Date birthDayEnd;
}

private Specification<User> getListSpec(UserDTO userDTO) {
    return (root, criteriaQuery, criteriaBuilder) -> {
        List<Predicate> predicateList = new ArrayList<>();
        // 未删除标识，只查询未删除的数据
        predicateList.add(criteriaBuilder.equal(root.get("deleteFlag"), 0));
        // 根据 用户名 或 年龄List 查询
        List<Predicate> usernameOrAgePredicate = new ArrayList<>();
        String username = userDTO.getUsername();
        if (!StringUtils.isEmpty(username)) {
            // 用户名这里，用模糊匹配
            usernameOrAgePredicate.add(criteriaBuilder.like(root.get("username"), "%" + username + "%"));
        }
        List<Integer> ageList = userDTO.getAgeList();
        if (!CollectionUtils.isEmpty(ageList)) {
            // 下面是一个 IN查询
            CriteriaBuilder.In<Integer> in = criteriaBuilder.in(root.get("age"));
            ageList.forEach(in::value);
            usernameOrAgePredicate.add(in);
        }
        /* 下面这一行代码很重要。
         * criteriaBuilder.or(Predicate... restrictions) 接收多个Predicate，可变参数；
         * 这多个 Predicate条件之间，是使用OR连接的；该方法最终返回 一个Predicate对象；
         */
        predicateList.add(criteriaBuilder.or(usernameOrAgePredicate.toArray(new Predicate[0])));
        // 用户ID List，IN 查询
        List<Integer> userIdList = reqDTO.getUserIdList();
        if (!CollectionUtils.isEmpty(userIdList)) {
            CriteriaBuilder.In<Integer> in = criteriaBuilder.in(root.get("id"));
            userIdList.forEach(in::value);
            predicateList.add(in);
        }
        // 生日时间段查询
        Date birthDayBegin = reqDTO.getBirthDayBegin();
        Date birthDayEnd = reqDTO.getBirthDayEnd();
        if (birthDayBegin != null && birthDayEnd != null) {
            // DateUtils 是我自定义的一个工具类
            Date begin = DateUtils.startOfDay(birthDayBegin);
            Date end = DateUtils.endOfDay(birthDayEnd);
            predicateList.add(criteriaBuilder.greaterThanOrEqualTo(root.get("birthDay"), begin));
            predicateList.add(criteriaBuilder.lessThanOrEqualTo(root.get("birthDay"), end));
        }
        // 最终，使用AND 连接 多个 Predicate 查询条件
        return criteriaBuilder.and(predicateList.toArray(new Predicate[0]));
    };
}

Specification<User> querySpec = this.getListSpec(userDTO);
List<User> userList = userDAO.findAll(querySpec);

SELECT * 
FROM   user 
WHERE  user.deleteFlag = 0 
AND    ( user.username like '%{username}%' OR user.age IN ageList )
AND    user.id IN userIdList
AND    user.birthDay > birthDayBegin AND user.birthDay < birthDayEnd ;