QueryDsl - 중복 필터 where문 적용

필터 요청 - 중복 가능

클라이언트가 다음과 같이 요청을 한다.

http://localhost:8080/api/list?departmentFilter=A&departmentFilter=B&genderFilter=M&order=AGE

쿼리스트링을 살펴보면, departmentFilter 2개, genderFilter 1개, order 1개이다.

쿼리스트링의 모든 값 중에서 하나라도 해당하면 조회가 가능하도록 설계해보자.

 

먼저, Controller에서 요청 받는 부분이다.

 

Controller.java

@GetMapping("/list")
public ResponseEntity<List<PersonnelListResponse>> personnelList(
    @RequestParam(value = "departmentFilter", required = false) List<DepartmentType> departmentFilter,
    @RequestParam(value = "genderFilter", required = false) Gender genderFilter,
    @RequestParam(value = "order", required = false) PersonnelOrderCondRequest orderCond
    ){

    if(departmentFilter == null)
        departmentFilter = new ArrayList<>();

    List<PersonnelListResponse> responseDto = personnelService.personnelList(
        new PersonnelFilterCondRequest(departmentFilter, genderFilter), orderCond);

    return ResponseEntity.ok(responseDto);
}

departmentFilter는 여러 값을 받아야하기에 List로 선언해주어야 한다. 참고로 DepartmentType, Gender는 Enum 타입, order는 정렬 조건이다.

 

다른 계층에서 departmentFilter를 조작하기 전에 null체크를 한번 더 해주어야 하기 때문에 Controller에서 ArrayList로 초기화한다.

 

다음은 Querydsl로 작성한 코드이다.

Repository.java

private BooleanExpression filterEq(PersonnelFilterCondRequest filterCond){
  final BooleanExpression[] booleanExpressionDepartmentType = new BooleanExpression[1];
  if(!filterCond.getDepartmentTypeList().isEmpty()){
      booleanExpressionDepartmentType[0] = (departmentTypeEq(filterCond.getDepartmentTypeList().get(0)));

      filterCond.getDepartmentTypeList().stream()
          .filter(departmentType -> !departmentType.equals(filterCond.getDepartmentTypeList().get(0)))
          .forEach(
              departmentType -> booleanExpressionDepartmentType[0] = (
                  departmentTypeEqOr(booleanExpressionDepartmentType[0], departmentType))
          );
  } else {
      booleanExpressionDepartmentType[0] = null;
  }
}

private BooleanExpression departmentTypeEq(DepartmentType departmentType){
  return departmentType != null ? personnel.departmentType.eq(departmentType) : null;
}

BooleanExpression은 서로 조립해서 사용할 수 있다는 특징이 있다.

이를 이용하여 먼저 departmentFilter List를 순회하여 각각의 BooleanExpression을 만들어준다.

private BooleanExpression departmentTypeEqOr(BooleanExpression booleanExpression, DepartmentType departmentType){
  return booleanExpression.or(departmentTypeEq(departmentType));
}

이 때 하나라도 조건이 만족하면 조회가 가능해야 하므로, or로 모든 BooleanExpression을 이어주어야한다.

BooleanExpression와 Filter 값을 null체크 하면서 gender도 마찬가지로 BooleanExpression값을 or로 이어준다.

private BooleanExpression filterEq(PersonnelFilterCondRequest filterCond){
  BooleanExpression booleanExpressionGender;
  if(!Objects.isNull(filterCond.getGender())){
      booleanExpressionGender = genderEq(filterCond.getGender());
  } else {
      booleanExpressionGender = null;
  }
}

private BooleanExpression genderEq(Gender gender){
  return gender != null ? personnel.gender.eq(gender) : null;
}

 

전체코드

 public List<PersonnelListResponse> findAllByCondition(PersonnelFilterCondRequest filterCond, PersonnelOrderCondRequest orderCond) {
  return queryFactory
    .select(Projections.constructor(PersonnelListResponse.class,
        personnel.id,
        personnel.name,
        personnel.dateOfBirth,
        personnel.phone,
        personnel.address,
        personnel.profileImage,
        personnel.departmentType
    ))
    .where(filterEq(filterCond))
    .from(personnel)
    .fetch();
}

private BooleanExpression filterEq(PersonnelFilterCondRequest filterCond){
  final BooleanExpression[] booleanExpressionDepartmentType = new BooleanExpression[1];
  if(!filterCond.getDepartmentTypeList().isEmpty()){
      booleanExpressionDepartmentType[0] = (departmentTypeEq(filterCond.getDepartmentTypeList().get(0)));

      filterCond.getDepartmentTypeList().stream()
          .filter(departmentType -> !departmentType.equals(filterCond.getDepartmentTypeList().get(0)))
          .forEach(
              departmentType -> booleanExpressionDepartmentType[0] = (
                  departmentTypeEqOr(booleanExpressionDepartmentType[0], departmentType))
          );
  } else {
      booleanExpressionDepartmentType[0] = null;
  }

  BooleanExpression booleanExpressionGender;
  if(!Objects.isNull(filterCond.getGender())){
      booleanExpressionGender = genderEq(filterCond.getGender());
  } else {
      booleanExpressionGender = null;
  }

  if(booleanExpressionDepartmentType[0] == null){
      return booleanExpressionGender;
  }

  return booleanExpressionDepartmentType[0].or(booleanExpressionGender);
}

private BooleanExpression departmentTypeEq(DepartmentType departmentType){
  return departmentType != null ? personnel.departmentType.eq(departmentType) : null;
}

private BooleanExpression departmentTypeEqOr(BooleanExpression booleanExpression, DepartmentType departmentType){
  return booleanExpression.or(departmentTypeEq(departmentType));
}

private BooleanExpression genderEq(Gender gender){
  return gender != null ? personnel.gender.eq(gender) : null;
}