상황

queryDsl에서 지원했는 fetchResults와 fetchCount가 deprecate된다고 한다.

그렇기에 이전에 지원했는 fetchResults에서 제공하는 count 쿼리를 직접 작성해서 크기를 구해야 한다.

deprecate 되기 이전 버전 코드

public class MemberRepositoryImpl implements MemberRepositoryCustom{

    private final JPAQueryFactory queryFactory;

    public MemberRepositoryImpl(JPAQueryFactory queryFactory) {
        this.queryFactory = queryFactory;
    }

    @Override
    public Page<MemberTeamDto> searchPageSimple(MemberSearchCondition condition, Pageable pageable) {
        QueryResults<MemberTeamDto> result = queryFactory
                .select(new QMemberTeamDto(
                        member.id.as("memberId"),
                        member.username,
                        member.age,
                        team.id.as("teamId"),
                        team.name.as("teamName")
                ))
                .from(member)
                .leftJoin(member.team, team)
                .where(
                        usernameEq(condition.getUsername()),
                        teamNameEq(condition.getTeamName()),
                        ageGoe(condition.getAgeGoe()),
                        ageLoe(condition.getAgeLoe())
                )
                .offset(pageable.getOffset())
                .limit(pageable.getPageSize())
                .fetchResults();

        List<MemberTeamDto> content = result.getResults();
        long total = result.getTotal();

        return new PageImpl<>(content, pageable, total);
    }

    private BooleanExpression usernameEq(String username) {
        return hasText(username) ? member.username.eq(username) : null;
    }

    private BooleanExpression teamNameEq(String teamName) {
        return hasText(teamName) ? team.name.eq(teamName) : null;
    }

    private BooleanExpression ageGoe(Integer ageGoe) {
        return ageGoe != null ? member.age.goe(ageGoe) : null;
    }

    private BooleanExpression ageLoe(Integer ageLoe) {
        return ageLoe != null ? member.age.loe(ageLoe) : null;
    }
}

deprecate된 이후 버전

@Override
public Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition, Pageable pageable) {
    List<MemberTeamDto> content = queryFactory
            .select(new QMemberTeamDto(
                    member.id.as("memberId"),
                    member.username,
                    member.age,
                    team.id.as("teamId"),
                    team.name.as("teamName")
            ))
            .from(member)
            .leftJoin(member.team, team)
            .where(
                    usernameEq(condition.getUsername()),
                    teamNameEq(condition.getTeamName()),
                    ageGoe(condition.getAgeGoe()),
                    ageLoe(condition.getAgeLoe())
            )
            .offset(pageable.getOffset())
            .limit(pageable.getPageSize())
            .fetch();

    JPAQuery<Long> countQuery = queryFactory
            .select(member.count())
            .from(member)
            .leftJoin(member.team, team)
            .where(
                    usernameEq(condition.getUsername()),
                    teamNameEq(condition.getTeamName()),
                    ageGoe(condition.getAgeGoe()),
                    ageLoe(condition.getAgeLoe())
            );

    //return new PageImpl<>(content, pageable, total);
    return PageableExecutionUtils.getPage(content, pageable, countQuery::fetchOne);
}

참고 자료

https://jjunn93.com/entry/Querydsl-페이징-연동-Querydsl-fetchResults-fetchCount-Deprecated향후-미지원