SpringDataJPA的几个使用记录

 public Page<XMGLFileTemplateDTO> findXMGLFileTemplateByConditions(XMGLFileTemplateDTO xmglFileTemplateDTO, Pageable pageable) throws MyException {
        Page<XMGLFileTemplate> XMGLFileTemplateLists = this.xmglFileTemplateRepository.findAll(new Specification<XMGLFileTemplate>() {
            @Override
            public Predicate toPredicate(Root<XMGLFileTemplate> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                List<Predicate> predicateList = new ArrayList<Predicate>();
                //文档名称
                if(StringUtils.isNotBlank(xmglFileTemplateDTO.getFileName())){
                    predicateList.add(criteriaBuilder.like(root.get("fileName"),"%"+xmglFileTemplateDTO.getFileName()+"%"));
                }
                //上传人员
                if(StringUtils.isNotBlank(xmglFileTemplateDTO.getUploadUserName())){
                    predicateList.add(criteriaBuilder.like(root.get("rsglSysUser").get("name"),"%"+xmglFileTemplateDTO.getUploadUserName()+"%"));
                }
                //重要性
                if(null != xmglFileTemplateDTO.getImportantLevel()){
                    predicateList.add(criteriaBuilder.equal(root.get("importantLevel"),xmglFileTemplateDTO.getImportantLevel()));
                }

                //交易时间
                if (null != xmglFileTemplateDTO.getUploadBeginTime() && null != xmglFileTemplateDTO.getUploadEndTime()) {
                    predicateList.add(criteriaBuilder.and(criteriaBuilder.greaterThanOrEqualTo(root.get("uploadTime"), DateUtils.parseDateTime(xmglFileTemplateDTO.getUploadBeginTime() + " 00:00:00")),
                        criteriaBuilder.lessThanOrEqualTo(root.get("uploadTime"), DateUtils.parseDateTime(xmglFileTemplateDTO.getUploadEndTime() + " 23:59:59"))));
                } else if (null != xmglFileTemplateDTO.getUploadBeginTime()) {
                    predicateList.add(criteriaBuilder.greaterThanOrEqualTo(root.get("uploadTime"),DateUtils.parseDateTime(xmglFileTemplateDTO.getUploadBeginTime() + " 00:00:00")));
                } else if (null != xmglFileTemplateDTO.getUploadEndTime()) {
                    predicateList.add(criteriaBuilder.lessThanOrEqualTo(root.get("uploadTime"),DateUtils.parseDateTime(xmglFileTemplateDTO.getUploadEndTime() + " 23:59:59")));
                }
                criteriaQuery.where(predicateList.toArray(new Predicate[0]));
                //更新时间倒序排序
                criteriaQuery.orderBy(criteriaBuilder.desc(root.get("uploadTime")));
                return null;
            }
        }, pageable);
        List<XMGLFileTemplateDTO> xmglFileTemplateDTOs = new ArrayList<XMGLFileTemplateDTO>();
        for (XMGLFileTemplate xmglFileTemplate : XMGLFileTemplateLists.getContent()) {//把分页对象转换为list对象 因为
            XMGLFileTemplateDTO dto = new XMGLFileTemplateDTO();
            BeanUtils.copyProperties(xmglFileTemplate, dto);//把接受前台参数的DTO和doman层的进行匹配拷贝
            dto.setUploadUserName(xmglFileTemplate.getRsglSysUser().getName());
            xmglFileTemplateDTOs.add(dto);//加入list集合
        }
        return new CustomPageImpl<XMGLFileTemplateDTO>(xmglFileTemplateDTOs, pageable,XMGLFileTemplateLists.getTotalElements());
    }

services层，使用对象分页查询