📌JPA Specifiacation

DB쿼리 조건을 간단히 Spec으로 작성하여 날릴 수 있게 해줍니다.

하나의 검색을 위한 @GetMapping이 있다고 할때, 시간이 흐를수록 점점 조건이 추가될 수록 코드가 덧붙여지며 유지보수가 힘들다.

이때, Spec으로 관리하게 되면 코드가 깔끔해지며 유지보수가 좀 더 용이 해진다.

-> 나같은 경우는 검색조건을 구현하기 위해 사용해주었다.

내가 사용해본 spec은 eq와 between만을 사용해주었고, 해당 검색 부분이 null값이면 그 외 값을 다 넣어주도록 설계를 해주었다.

작성한 코드

package com.realEstate.realEstate.model.dto.querydsl;

import com.querydsl.core.types.dsl.BooleanExpression;
import com.realEstate.realEstate.model.constant.CType;
import com.realEstate.realEstate.model.constant.Structure;
import com.realEstate.realEstate.model.entity.QProperty;

public class PropertySearchCriteria {
    private final BooleanExpression predicate;

    public PropertySearchCriteria(CType transactionType, Integer minPrice, Integer maxPrice,
                                  Integer minArea, Integer maxArea, Integer minFloor, Integer maxFloor,
                                  Structure structure, Boolean sink, Boolean airConditioner, Boolean shoeRack,
                                  Boolean washingMachine, Boolean refrigerator, Boolean wardrobe, Boolean gasRange,
                                  Boolean induction, Boolean bed, Boolean desk, Boolean microwave, Boolean bookshelf,
                                  Integer minDeposit, Integer maxDeposit, Integer minMonthlyRent, Integer maxMonthlyRent) {
        QProperty property = QProperty.property;

        BooleanExpression transactionTypeExpression = transactionType == null ? property.transactionType.isNotNull() :
                property.transactionType.eq(transactionType);

        BooleanExpression structureExpression = structure == null ? property.structure.isNotNull() :
                property.structure.eq(structure);

        BooleanExpression sinkExpression = sink == null ? property.option.sink.isNotNull() :
                property.option.sink.eq(sink);

        BooleanExpression airConditionerExpression = airConditioner == null ? property.option.airConditioner.isNotNull() :
                property.option.airConditioner.eq(airConditioner);

        BooleanExpression shoeRackExpression = shoeRack == null ? property.option.shoeRack.isNotNull() :
                property.option.shoeRack.eq(shoeRack);

        BooleanExpression washingMachineExpression = washingMachine == null ? property.option.washingMachine.isNotNull() :
                property.option.washingMachine.eq(washingMachine);

        BooleanExpression refrigeratorExpression = refrigerator == null ? property.option.refrigerator.isNotNull() :
                property.option.refrigerator.eq(refrigerator);

        BooleanExpression wardrobeExpression = wardrobe == null ? property.option.wardrobe.isNotNull() :
                property.option.wardrobe.eq(wardrobe);

        BooleanExpression gasRangeExpression = gasRange == null ? property.option.gasRange.isNotNull() :
                property.option.gasRange.eq(gasRange);

        BooleanExpression inductionExpression = induction == null ? property.option.induction.isNotNull() :
                property.option.induction.eq(induction);

        BooleanExpression bedExpression = bed == null ? property.option.bed.isNotNull() :
                property.option.bed.eq(bed);

        BooleanExpression deskExpression = desk == null ? property.option.desk.isNotNull() :
                property.option.desk.eq(desk);

        BooleanExpression microwaveExpression = microwave == null ? property.option.microwave.isNotNull() :
                property.option.microwave.eq(microwave);

        BooleanExpression bookshelfExpression = bookshelf == null ? property.option.bookshelf.isNotNull() :
                property.option.bookshelf.eq(bookshelf);

        BooleanExpression minPriceExpression = transactionType == CType.SALE && minPrice != null ?
                property.price.goe(minPrice) : null;

        BooleanExpression maxPriceExpression = transactionType == CType.SALE && maxPrice != null ?
                property.price.loe(maxPrice) : null;

        BooleanExpression depositExpression = minDeposit == null && maxDeposit == null ?
                property.deposit.isNotNull() : property.deposit.between(minDeposit, maxDeposit);

        BooleanExpression monthlyRentExpression = minMonthlyRent == null && maxMonthlyRent == null ?
                property.monthlyRent.isNotNull() : property.monthlyRent.between(minMonthlyRent, maxMonthlyRent);

        this.predicate = transactionTypeExpression
                .and(structureExpression)
                .and(minPriceExpression)
                .and(maxPriceExpression)
                .and(minArea != null && maxArea != null ? property.area.between(minArea, maxArea) : property.area.isNotNull())
                .and(minFloor != null && maxFloor != null ? property.floor.between(minFloor, maxFloor) : property.floor.isNotNull())
                .and(sinkExpression)
                .and(airConditionerExpression)
                .and(shoeRackExpression)
                .and(washingMachineExpression)
                .and(refrigeratorExpression)
                .and(wardrobeExpression)
                .and(gasRangeExpression)
                .and(inductionExpression)
                .and(bedExpression)
                .and(deskExpression)
                .and(microwaveExpression)
                .and(bookshelfExpression)
                .and(depositExpression)
                .and(monthlyRentExpression);
    }

    public BooleanExpression getPredicate() {
        return predicate;
    }
}