SpringJPA 做分页条件查询的代码实践

@RestController
public class ProductInstanceController {
    @Autowired
    private ProductInstanceService productInstanceService;
    @PostMapping("page-find-instance")
    public PageInfoVO<ProductInst> pageFindInstance(@RequestBody ProductInstParams productInstParams) {
        return productInstanceService.pageFindInstance(productInstParams);
    }
}

@Service
public class ProductInstanceService {
    @Autowired
    private ProductInstRepository productInstRepository;
    public PageInfoVO<ProductInst> pageFindInstance(ProductInstParams productInstParams) {
        Sort.Direction direction = Sort.Direction.DESC;
        //创建一个Pageable对象，其中包含了请求的页码(productInstParams.getPageNo())，每页大小(productInstParams.getPageSize())，排序规则以及排序字段名。
        Pageable pageable = PageRequest.of(productInstParams.getPageNo(), productInstParams.getPageSize(), direction, "createdTime");
		//将传入的字符串类型的开始日期(startDate)和结束日期(endDate)转换成Date类型
        Date start = DateUtil.parseUTC(productInstParams.getStartDate());
        Date end = DateUtil.parseUTC(productInstParams.getEndDate());
        //执行JPA分页查询：
        Page<ProductInst> productInstPage = productInstRepository.findAll((root, query, criteriaBuilder) -> {
        //初始化一个ArrayList<Predicate>，存储多个谓词条件，这些条件最终会被组合成一个逻辑与（AND）表达式
            List<Predicate> predicatesAndList = new ArrayList<>();
            // deleted = 'true'
            if (null != productInstParams.getIsDeleted()) {
				predicatesAndList.add(criteriaBuilder.equal(root.get("deleted").as(Boolean.class), productInstParams.getIsDeleted()));
            }
            // name like %name%
            if (StringUtils.isNotBlank(productInstParams.getName())) {
                predicatesAndList.add(criteriaBuilder.like(root.get("name").as(String.class), productInstParams.getName()));
            }
            // runStatus = "运行中"
            if (StringUtils.isNotBlank(productInstParams.getRunStatus())) {
                predicatesAndList.add(criteriaBuilder.equal(root.get("runStatus").as(String.class), productInstParams.getRunStatus()));
            }
            // createdTime >= start
            if (!Objects.isNull(start)) {
                predicatesAndList.add(criteriaBuilder.greaterThanOrEqualTo(root.get("createdTime").as(Date.class), start));
            }
            // createdTime <= end
            if (!Objects.isNull(end)) {
                predicatesAndList.add(criteriaBuilder.lessThanOrEqualTo(root.get("createdTime").as(Date.class), end));
            }
            // id in ('1','2')
            if (!CollectionUtils.isEmpty(productInstParams.getIds())) {
                CriteriaBuilder.In<String> in = criteriaBuilder.in(root.get("id").as(String.class));
                productInstParams.getIds().forEach(in::value);
                predicatesAndList.add(in);
            }
            Predicate andPredicate = criteriaBuilder.and(predicatesAndList.toArray(new Predicate[predicatesAndList.size()]));
            query.where(andPredicate);
            return query.getRestriction();
        }, pageable);
        return PageUtil.generatePageInfoVO(productInstPage);
    }
}

criteriaBuilder.equal(root.get("runStatus").as(String.class), productInstParams.getRunStatus());

WHERE run_status = 'XXXX'

@Repository
public interface ProductInstRepository extends JpaRepository<ProductInst, String>, JpaSpecificationExecutor<ProductInst> {
}

package com.king.alice.common.base;
import lombok.Getter;
import lombok.Setter;
import java.util.List;
/**
 * @Author wlt
 * @Description 分页数据中的元素
 * @Date 2022/8/26
 **/
@Getter
@Setter
public class PageInfoVO<T> extends BaseVO{
    private static final long serialVersionUID = -3542944936096780651L;
    /**
     * 总记录数
     */
    private long total;
    /**
     * 当前页
     */
    private int pageNum;
    /**
     * 每页的数量
     */
    private int pageSize;
    /**
     * 结果集
     */
    private List<T> list;
}

package com.king.alice.common.util;
import com.king.alice.common.base.PageInfoVO;
import org.springframework.data.domain.Page;
/**
 * @author 大魔王
 * @description:
 * @date 2024/3/22 11:02
 */
public class PageUtil {
    /**
     * 根据Page对象生成PageInfoVO
     *
     * @param page Page包装对象
     * @return PageDto 对象
     */
    @SuppressWarnings({"unchecked"})
    public static <T> PageInfoVO<T> generatePageInfoVO(Page page) {
        PageInfoVO result = new PageInfoVO();
        result.setPageNum(page.getNumber() + 1);
        result.setPageSize(page.getPageable().getPageSize());
        result.setTotal(page.getTotalElements());
        result.setList(page.getContent());
        return result;
    }
}

package com.king.alice.manage.instance.params;
import lombok.Data;
import java.util.List;
/**
 * @author 大魔王
 * @description: TODO
 * @date 2024/3/21 16:56
 */
@Data
public class ProductInstParams {
    /**
     * 当前页
     */
    private int pageNo;
    /**
     * 每页的数量
     */
    private int pageSize;
    /**
     * 名字
     */
    private List<String> ids;
    /**
     * 名字
     */
    private String name;
    /**
     * 运行状态
     */
    private String runStatus;
    private String startDate;
    private String endDate;
    private Boolean isDeleted;
}