[WTH-65] @Query 기반 JPQL을 QueryDSL로 리팩토링

build.gradle

@@ -41,6 +41,12 @@ dependencies {
 	implementation 'io.jsonwebtoken:jjwt-jackson:0.11.5'
 	implementation 'com.auth0:java-jwt:4.2.1'
 
+	// QueryDSL
+	implementation 'com.querydsl:querydsl-jpa:5.0.0:jakarta'
+	annotationProcessor 'com.querydsl:querydsl-apt:5.0.0:jakarta'
+	annotationProcessor 'jakarta.persistence:jakarta.persistence-api:3.1.0'
+	annotationProcessor 'jakarta.annotation:jakarta.annotation-api:2.1.1'
+
 	// mapStruct
 	implementation 'org.mapstruct:mapstruct:1.5.3.Final'
 	annotationProcessor 'org.mapstruct:mapstruct-processor:1.5.3.Final'

src/main/java/leets/weeth/domain/board/domain/repository/PostRepository.java

@@ -12,7 +12,7 @@
 import org.springframework.data.repository.query.Param;
 
 
-public interface PostRepository extends JpaRepository<Post, Long> {
+public interface PostRepository extends JpaRepository<Post, Long>, PostRepositoryCustom {
 
 	@Query("""
         SELECT p FROM Post p

src/main/java/leets/weeth/domain/board/domain/repository/PostRepositoryCustom.java

@@ -0,0 +1,26 @@
+package leets.weeth.domain.board.domain.repository;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
+import org.springframework.data.repository.query.Param;
+
+import leets.weeth.domain.board.domain.entity.Post;
+import leets.weeth.domain.board.domain.entity.enums.Category;
+import leets.weeth.domain.board.domain.entity.enums.Part;
+
+public interface PostRepositoryCustom {
+
+	Slice<Post> findRecentPart(Pageable pageable);
+	Slice<Post> findRecentEducation(Pageable pageable);
+	Slice<Post> searchPart(String kw,Pageable pageable);
+	Slice<Post> searchEducation(String kw, Pageable pageable);
+	List<String> findDistinctStudyNamesByPart(Part part);
+	Slice<Post> findByPartAndOptionalFilters(Part part, Category category, Integer cardinal, String studyName, Integer week, Pageable pageable);
+	Slice<Post> findByCategoryAndOptionalCardinalWithPart(String partName, Category category, Integer cardinal, Pageable pageable);
+	Slice<Post> findByCategoryAndCardinalNumberWithPart(String partName, Category category, Integer cardinal, Pageable pageable);
+	Slice<Post> findByCategoryAndCardinalInWithPart(String partName, Category category,  Collection<Integer> cardinals, Pageable pageable);
+
+}

src/main/java/leets/weeth/domain/board/domain/repository/PostRepositoryImpl.java

@@ -0,0 +1,279 @@
+package leets.weeth.domain.board.domain.repository;
+
+import java.beans.Expression;
+import java.util.Collection;
+import java.util.List;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
+import org.springframework.data.domain.SliceImpl;
+import org.springframework.data.repository.query.Param;
+import org.springframework.security.core.parameters.P;
+import org.springframework.stereotype.Repository;
+
+import com.querydsl.core.BooleanBuilder;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.core.types.dsl.Expressions;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+
+import jakarta.persistence.EntityManager;
+import leets.weeth.domain.board.domain.entity.Post;
+import leets.weeth.domain.board.domain.entity.QPost;
+import leets.weeth.domain.board.domain.entity.enums.Category;
+import leets.weeth.domain.board.domain.entity.enums.Part;
+import lombok.RequiredArgsConstructor;
+
+
+public class PostRepositoryImpl implements PostRepositoryCustom {
+
+	private final JPAQueryFactory queryFactory;
+	private final QPost post = QPost.post;
+
+	public PostRepositoryImpl(EntityManager em) {
+		this.queryFactory = new JPAQueryFactory(em);
+	}
+
+	@Override
+	public Slice<Post> findRecentPart(Pageable pageable) {
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(post.category.in(Category.StudyLog, Category.Article))
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+
+		if (hasNext) {
+			result.remove(pageable.getPageSize());
+		}
+
+		return new SliceImpl<>(result, pageable, hasNext);
+	}
+
+	@Override
+	public Slice<Post> searchPart(String kw, Pageable pageable) {
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(post.category.in(Category.StudyLog, Category.Article)
+				.and(post.title.containsIgnoreCase(kw)
+					.or(post.content.containsIgnoreCase(kw))
+			))
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+
+		if (hasNext) {
+			result.remove(pageable.getPageSize());
+		}
+
+		return new SliceImpl<>(result, pageable, hasNext);
+ 	}
+
+	 @Override
+	 public Slice<Post> findRecentEducation(Pageable pageable) {
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(post.category.eq(Category.Education))
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+
+		if (hasNext) {
+			result.remove(pageable.getPageSize());
+		}
+
+		return new SliceImpl<>(result, pageable, hasNext);
+	 }
+
+	 @Override
+	public Slice<Post> searchEducation(String kw, Pageable pageable) {
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(
+				post.category.eq(Category.Education)
+					.and(
+						post.title.containsIgnoreCase(kw)
+							.or(post.content.containsIgnoreCase(kw))
+					)
+			)
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		 boolean hasNext = result.size() > pageable.getPageSize();
+
+		 if (hasNext) {
+			 result.remove(pageable.getPageSize());
+		 }
+
+		 return new SliceImpl<>(result, pageable, hasNext);
+	 }
+
+	 @Override
+	public List<String> findDistinctStudyNamesByPart(Part part) {
+
+		 return queryFactory
+			 .select(post.studyName)
+			 .distinct()
+			 .from(post)
+			 .where(
+				 part == Part.ALL
+					 ? post.studyName.isNotNull()
+					 : post.part.eq(part).and(post.studyName.isNotNull())
+			 )
+			 .orderBy(post.studyName.asc())
+			 .fetch();
+	}
+
+	@Override //조건이 많은 쿼리라 BooleanBuilder 사용
+	public Slice<Post> findByPartAndOptionalFilters(Part part, Category category, Integer cardinal, String studyName, Integer week, Pageable pageable) {
+
+		BooleanBuilder builder = new BooleanBuilder();
+
+		if (part == Part.ALL) {
+			builder.and(post.part.eq(Part.ALL).or(post.part.ne(Part.ALL)));
+		}else {
+			builder.and(post.part.eq(part).or(post.part.eq(Part.ALL)));
+		}
+
+		if (category != null) {
+			builder.and(post.category.eq(category));
+		}
+
+		if (cardinal != null) {
+			builder.and(post.cardinalNumber.eq(cardinal));
+		}
+
+		if (studyName != null) {
+			builder.and(post.studyName.eq(studyName));
+		}
+
+		if (week != null) {
+			builder.and(post.week.eq(week));
+		}
+
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(builder)
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+
+		if (hasNext) {
+			result.remove(pageable.getPageSize());
+		}
+		return new SliceImpl<>(result, pageable, hasNext);
+
+	}
+
+	@Override
+	public Slice<Post> findByCategoryAndOptionalCardinalWithPart(String partName, Category category, Integer cardinal, Pageable pageable) {
+
+		BooleanBuilder builder = new BooleanBuilder();
+
+		builder.and(post.category.eq(category));
+
+		if (cardinal != null) {
+			builder.and(post.cardinalNumber.eq(cardinal));
+		}
+
+		if (!"ALL".equals(partName)) { //partName 조건
+			builder.and(
+				Expressions.numberTemplate(Integer.class,
+						"FIND_IN_SET({0}, {1})", partName, post.parts).gt(0)
+					.or(Expressions.numberTemplate(Integer.class,
+						"FIND_IN_SET('ALL', {0})", post.parts).gt(0))
+			);
+		}
+
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(builder)
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+		boolean hasNext = result.size() > pageable.getPageSize();
+		if (hasNext) result.remove(pageable.getPageSize());
+
+		return new SliceImpl<>(result, pageable, hasNext);
+	}
+
+	@Override
+	public Slice<Post> findByCategoryAndCardinalNumberWithPart(String partName, Category category, Integer cardinal, Pageable pageable) {
+
+		BooleanBuilder builder = new BooleanBuilder();
+
+		builder.and(post.category.eq(category));
+		builder.and(post.cardinalNumber.eq(cardinal));
+
+		if (!"ALL".equals(partName)) {
+			BooleanExpression containsPart =
+				Expressions.numberTemplate(Integer.class, "FIND_IN_SET({0}, {1})", partName, post.parts).gt(0);
+
+			BooleanExpression containsAll =
+				Expressions.numberTemplate(Integer.class,
+					"FIND_IN_SET('ALL', {0})", post.parts).gt(0);
+
+			builder.and(containsPart.or(containsAll));
+		}
+
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(builder)
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+		if (hasNext) result.remove(pageable.getPageSize());
+
+		return new SliceImpl<>(result, pageable, hasNext);
+	}
+
+	@Override
+	public Slice<Post> findByCategoryAndCardinalInWithPart(String partName, Category category,  Collection<Integer> cardinals, Pageable pageable) {
+		BooleanBuilder builder = new BooleanBuilder();
+
+		builder.and(post.category.eq(category));
+		builder.and(post.cardinalNumber.in(cardinals));
+
+		if (!"ALL".equals(partName)) {
+			BooleanExpression containsPart =
+				Expressions.numberTemplate(Integer.class,
+					"FIND_IN_SET({0}, {1})", partName, post.parts).gt(0);
+
+			BooleanExpression containsAll =
+				Expressions.numberTemplate(Integer.class,
+					"FIND_IN_SET('ALL', {0})", post.parts).gt(0);
+
+			builder.and(containsPart.or(containsAll));
+		}
+
+		List<Post> result = queryFactory
+			.selectFrom(post)
+			.where(builder)
+			.orderBy(post.id.desc())
+			.offset(pageable.getOffset())
+			.limit(pageable.getPageSize() + 1)
+			.fetch();
+
+		boolean hasNext = result.size() > pageable.getPageSize();
+		if (hasNext) result.remove(pageable.getPageSize());
+
+		return new SliceImpl<>(result, pageable, hasNext);
+	}
+}

src/main/java/leets/weeth/global/config/QuerydslConfig.java

@@ -0,0 +1,17 @@
+package leets.weeth.global.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.querydsl.jpa.impl.JPAQueryFactory;
+
+import jakarta.persistence.EntityManager;
+
+@Configuration
+public class QuerydslConfig {
+
+	@Bean
+	public JPAQueryFactory jpaQueryFactory(EntityManager em) {
+		return new JPAQueryFactory(em);
+	}
+}