多排序可选查询-带有分页的Spring REST控制器配置

Question

我想构建一个能够处理多个可选排序查询的spring控制器。根据Spring.io规范，这些查询应该这样格式化

&sort=name,desc&sort=code,desc

域

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class Subject {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String code; 
...

储存库

public interface SubjectRepository extends JpaRepository<Subject, Long> {
}

服务

@Override
public Page<SubjectDTO> listSubjectsPageble(PageRequest pageableRequest) {
    return subjectRepository.findAll(pageableRequest)
            .map(subjectMapper::subjectToSubjectDTO);
}

@GetMapping
@ResponseStatus(HttpStatus.OK)
@PreAuthorize("hasRole('LECTURER')")
public Page<SubjectDTO> getSubjects(
        @RequestParam("page") int page,
        @RequestParam("size") int size,
        @RequestParam("sort") String sort

) {

    return subjectService.listSubjectsPageble(PageRequest.of(page, size, new Sort(sort)));
}

@RequestParam MultiValueMap<String, String> params

@GetMapping
    @ResponseStatus(HttpStatus.OK)
    @PreAuthorize("hasRole('LECTURER')")
    public Page<SubjectDTO> getSubjects(
            @RequestParam(value = "page", defaultValue = "0", required = false) int page,
            @RequestParam(value = "size", defaultValue = "10", required = false) int size,
            @RequestParam(value = "sort", defaultValue = "name,ASC", required = false) String sortBy

    ) {
        String[] sort = sortBy.split(",");
        String evalSort = sort[0];
        String sortDirection = sort[1];
        Sort.Direction evalDirection = replaceOrderStringThroughDirection(sortDirection);
        Sort sortOrderIgnoreCase = Sort.by(new Sort.Order(evalDirection,evalSort).ignoreCase());

        return subjectService.listSubjectsPageble(PageRequest.of(page, size, sortOrderIgnoreCase));
    }

    private Sort.Direction replaceOrderStringThroughDirection(String sortDirection) {
        if (sortDirection.equalsIgnoreCase("DESC")){
            return Sort.Direction.DESC;
        } else {
            return Sort.Direction.ASC;
        }
    }

@GetMapping
@ResponseStatus(HttpStatus.OK)
@PreAuthorize("hasRole('LECTURER')")
public Page<SubjectDTO> getSubjects(
        @RequestParam(value = "page", defaultValue = "0", required = false) int page,
        @RequestParam(value = "size", defaultValue = "10", required = false) int size,
        @RequestParam(value = "sort", defaultValue = "name;ASC", required = false) String[] sortBy

Sort allSorts = Sort.by(
        Arrays.stream(sortBy)
                .map(sort -> sort.split(";", 2))
                .map(array ->
                        new Sort.Order(replaceOrderStringThroughDirection(array[1]),array[0]).ignoreCase()
                ).collect(Collectors.toList())
);
return subjectService.listSubjectsPageble(PageRequest.of(page, size, allSorts));

private Sort.Direction replaceOrderStringThroughDirection(String sortDirection) {
    if (sortDirection.equalsIgnoreCase("DESC")){
        return Sort.Direction.DESC;
    } else {
        return Sort.Direction.ASC;
    }

Answer 1

为什么不在控制器中使用分页呢？

Pageable可以处理许多排序查询，每个查询都将存储在orders列表中。而且，不需要任何可分页的参数。当您不在url中传递它们时，pageable将包含默认值（页面=0，size=20)。可以使用@PageableDefault注释更改默认值。