feat: 과목 조회 API 구현

src/main/java/kr/allcll/seatfinder/subject/Subject.java

@@ -6,9 +6,11 @@
 import jakarta.persistence.Id;
 import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
+import lombok.Getter;
 import lombok.NoArgsConstructor;
 
 @Entity
+@Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @AllArgsConstructor(access = AccessLevel.PUBLIC)
 public class Subject {

src/main/java/kr/allcll/seatfinder/subject/SubjectApi.java

@@ -4,8 +4,10 @@
 import kr.allcll.seatfinder.excel.SubjectSheetParser;
 import kr.allcll.seatfinder.excel.SubjectsParsingResponse;
 import kr.allcll.seatfinder.subject.dto.SubjectsRequest;
+import kr.allcll.seatfinder.subject.dto.SubjectsResponse;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
@@ -18,6 +20,24 @@ public class SubjectApi {
     private final SubjectService subjectService;
     private final SubjectSheetParser subjectSheetParser;
 
+    @GetMapping("/api/subjects")
+    public ResponseEntity<SubjectsResponse> getSubjects(
+        @RequestParam(required = false) Long subjectId,
+        @RequestParam(required = false) String subjectName,
+        @RequestParam(required = false) String subjectCode,
+        @RequestParam(required = false) String classCode,
+        @RequestParam(required = false) String professorName
+    ) {
+        SubjectsResponse subjectsResponse = subjectService.findSubjectsByCondition(
+            subjectId,
+            subjectName,
+            subjectCode,
+            classCode,
+            professorName
+        );
+        return ResponseEntity.ok(subjectsResponse);
+    }
+
     @PostMapping("/api/subject/upload")
     public ResponseEntity<String> uploadSubjects(@RequestParam MultipartFile file) throws IOException {
         SubjectsParsingResponse parsedSubjects = subjectSheetParser.parse(file);

src/main/java/kr/allcll/seatfinder/subject/SubjectRepository.java

@@ -1,7 +1,8 @@
 package kr.allcll.seatfinder.subject;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 
-public interface SubjectRepository extends JpaRepository<Subject, Long> {
+public interface SubjectRepository extends JpaRepository<Subject, Long>, JpaSpecificationExecutor<Subject> {
 
 }

src/main/java/kr/allcll/seatfinder/subject/SubjectService.java

@@ -2,17 +2,50 @@
 
 import java.util.List;
 import kr.allcll.seatfinder.subject.dto.SubjectsRequest;
+import kr.allcll.seatfinder.subject.dto.SubjectsResponse;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.jpa.domain.Specification;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
 @Service
+@Transactional(readOnly = true)
 @RequiredArgsConstructor
 public class SubjectService {
 
     private final SubjectRepository subjectRepository;
 
+    @Transactional
     public void save(SubjectsRequest subjectRequests) {
         List<Subject> subjects = subjectRequests.toEntity();
         subjectRepository.saveAll(subjects);
     }
+
+    public SubjectsResponse findSubjectsByCondition(
+        Long subjectId,
+        String subjectName,
+        String subjectCode,
+        String classCode,
+        String professorName
+    ) {
+        Specification<Subject> condition = getCondition(subjectId, subjectName, subjectCode, classCode, professorName);
+        List<Subject> subjects = subjectRepository.findAll(condition);
+        return SubjectsResponse.from(subjects);
+    }
+
+    private Specification<Subject> getCondition(
+        Long subjectId,
+        String subjectName,
+        String subjectCode,
+        String classCode,
+        String professorName
+    ) {
+        return Specification.where(
+                SubjectSpecifications.hasSubjectId(subjectId))
+            .and(SubjectSpecifications.hasSubjectName(subjectName))
+            .and(SubjectSpecifications.hasSubjectCode(subjectCode))
+            .and(SubjectSpecifications.hasClassCode(classCode))
+            .and(SubjectSpecifications.hasProfessorName(professorName)
+            );
+    }
 }

src/main/java/kr/allcll/seatfinder/subject/SubjectSpecifications.java

@@ -0,0 +1,31 @@
+package kr.allcll.seatfinder.subject;
+
+import org.springframework.data.jpa.domain.Specification;
+
+public class SubjectSpecifications {
+
+    public static Specification<Subject> hasSubjectId(Long subjectId) {
+        return (root, query, builder) ->
+            subjectId == null ? null : builder.equal(root.get("id"), subjectId);
+    }
+
+    public static Specification<Subject> hasSubjectName(String subjectName) {
+        return (root, query, builder) ->
+            subjectName == null ? null : builder.equal(root.get("subjectName"), subjectName);
+    }
+
+    public static Specification<Subject> hasSubjectCode(String subjectCode) {
+        return (root, query, builder) ->
+            subjectCode == null ? null : builder.equal(root.get("subjectCode"), subjectCode);
+    }
+
+    public static Specification<Subject> hasClassCode(String classCode) {
+        return (root, query, builder) ->
+            classCode == null ? null : builder.equal(root.get("classCode"), classCode);
+    }
+
+    public static Specification<Subject> hasProfessorName(String professorName) {
+        return (root, query, builder) ->
+            professorName == null ? null : builder.equal(root.get("professorName"), professorName);
+    }
+}

src/main/java/kr/allcll/seatfinder/subject/dto/SubjectResponse.java

@@ -0,0 +1,60 @@
+package kr.allcll.seatfinder.subject.dto;
+
+import kr.allcll.seatfinder.subject.Subject;
+
+public record SubjectResponse(
+    Long subjectId,
+    String offeringUniversity,
+    String offeringDepartment,
+    String subjectCode,
+    String classCode,
+    String subjectName,
+    String subjectType,
+    String electiveArea,
+    String academicYearSemester,
+    String credit,
+    String theoryHours,
+    String practiceHours,
+    String classType,
+    String exchangeEligible,
+    String schedule,
+    String lectureRoom,
+    String professorName,
+    String supervisingDepartment,
+    String notesAndRestrictions,
+    String classCategory,
+    String onlineLecture,
+    String lectureLanguage,
+    String foreignerOnly,
+    String domesticOnly
+) {
+
+    public static SubjectResponse from(Subject subject) {
+        return new SubjectResponse(
+            subject.getId(),
+            subject.getOfferingUniversity(),
+            subject.getOfferingDepartment(),
+            subject.getSubjectCode(),
+            subject.getClassCode(),
+            subject.getSubjectName(),
+            subject.getSubjectType(),
+            subject.getElectiveArea(),
+            subject.getAcademicYearSemester(),
+            subject.getCredit(),
+            subject.getTheoryHours(),
+            subject.getPracticeHours(),
+            subject.getClassType(),
+            subject.getExchangeEligible(),
+            subject.getSchedule(),
+            subject.getLectureRoom(),
+            subject.getProfessorName(),
+            subject.getSupervisingDepartment(),
+            subject.getNotesAndRestrictions(),
+            subject.getClassCategory(),
+            subject.getOnlineLecture(),
+            subject.getLectureLanguage(),
+            subject.getForeignerOnly(),
+            subject.getDomesticOnly()
+        );
+    }
+}

src/main/java/kr/allcll/seatfinder/subject/dto/SubjectsResponse.java

@@ -0,0 +1,15 @@
+package kr.allcll.seatfinder.subject.dto;
+
+import java.util.List;
+import kr.allcll.seatfinder.subject.Subject;
+
+public record SubjectsResponse(
+    List<SubjectResponse> subjectResponses
+) {
+
+    public static SubjectsResponse from(List<Subject> subjects) {
+        return new SubjectsResponse(subjects.stream()
+            .map(SubjectResponse::from)
+            .toList());
+    }
+}

src/test/java/kr/allcll/seatfinder/subject/SubjectApiTest.java

@@ -3,6 +3,7 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.BDDMockito.then;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.multipart;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@@ -32,6 +33,17 @@ class SubjectApiTest {
     @MockitoBean
     private SubjectService subjectService;
 
+    @DisplayName("과목을 조회한다.")
+    @Test
+    void getSubjectsApiTest() throws Exception {
+        mockMvc.perform(get("/api/subjects")
+                .param("subjectId", "1")
+                .param("subjectName", "컴퓨터구조"))
+            .andExpect(status().isOk());
+
+        then(subjectService).should().findSubjectsByCondition(1L, "컴퓨터구조", null, null, null);
+    }
+
     @DisplayName("과목 엑셀 파일을 업로드한다.")
     @Test
     void uploadSubjectsApiTest() throws Exception {

src/test/java/kr/allcll/seatfinder/subject/SubjectServiceTest.java

@@ -0,0 +1,90 @@
+package kr.allcll.seatfinder.subject;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.tuple;
+
+import java.util.List;
+import kr.allcll.seatfinder.subject.dto.SubjectResponse;
+import kr.allcll.seatfinder.subject.dto.SubjectsResponse;
+import kr.allcll.seatfinder.support.fixture.SubjectFixture;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+
+@SpringBootTest(webEnvironment = WebEnvironment.NONE)
+class SubjectServiceTest {
+
+    @Autowired
+    private SubjectService subjectService;
+
+    @Autowired
+    private SubjectRepository subjectRepository;
+
+    @BeforeEach
+    void setUp() {
+        subjectRepository.deleteAllInBatch();
+        initializeSubjects();
+    }
+
+    private void initializeSubjects() {
+        subjectRepository.saveAll(
+            List.of(
+                SubjectFixture.createSubject(null, "컴퓨터구조", "003278", "001", "유재석"),
+                SubjectFixture.createSubject(null, "운영체제", "003279", "001", "노홍철"),
+                SubjectFixture.createSubject(null, "자료구조", "003280", "001", "하하"),
+                SubjectFixture.createSubject(null, "알고리즘", "003281", "001", "길"),
+                SubjectFixture.createSubject(null, "컴퓨터구조", "003278", "002", "정형돈"),
+                SubjectFixture.createSubject(null, "운영체제", "003279", "002", "나영석"),
+                SubjectFixture.createSubject(null, "자료구조", "003280", "003", "박명수"),
+                SubjectFixture.createSubject(null, "알고리즘", "003281", "004", "전진")
+            )
+        );
+    }
+
+    @DisplayName("과목명으로 과목을 조회한다.")
+    @Test
+    void findSubjectByQueryTest() {
+        SubjectsResponse subjectsResponse = subjectService.findSubjectsByCondition(null, "컴퓨터구조", null, null, null);
+
+        assertThat(subjectsResponse.subjectResponses()).hasSize(2)
+            .extracting(
+                SubjectResponse::subjectName,
+                SubjectResponse::subjectCode,
+                SubjectResponse::classCode,
+                SubjectResponse::professorName
+            )
+            .containsExactly(
+                tuple("컴퓨터구조", "003278", "001", "유재석"),
+                tuple("컴퓨터구조", "003278", "002", "정형돈")
+            );
+    }
+
+    @DisplayName("학수번호, 분반, 교수명으로 과목을 조회한다.")
+    @Test
+    void findSubjectByQueryTest2() {
+        SubjectsResponse subjectsResponse = subjectService.findSubjectsByCondition(null, null, "003279", "001", "노홍철");
+
+        assertThat(subjectsResponse.subjectResponses()).hasSize(1)
+            .extracting(
+                SubjectResponse::subjectName,
+                SubjectResponse::subjectCode,
+                SubjectResponse::classCode,
+                SubjectResponse::professorName
+            )
+            .containsExactly(
+                tuple("운영체제", "003279", "001", "노홍철")
+            );
+    }
+
+    @DisplayName("존재하지 않는 조건으로 과목을 조회한다.")
+    @Test
+    void findSubjectByQueryTest3() {
+        SubjectsResponse subjectsResponse = subjectService.findSubjectsByCondition(100L, null, "003279", "001",
+            "유재석");
+
+        assertThat(subjectsResponse.subjectResponses()).hasSize(0);
+    }
+}

src/test/java/kr/allcll/seatfinder/support/fixture/SubjectFixture.java

@@ -0,0 +1,17 @@
+package kr.allcll.seatfinder.support.fixture;
+
+import kr.allcll.seatfinder.subject.Subject;
+
+public class SubjectFixture {
+
+    public static Subject createSubject(
+        Long subjectId,
+        String subjectName,
+        String subjectCode,
+        String classCode,
+        String professorName
+    ) {
+        return new Subject(subjectId, "", "", subjectCode, classCode, subjectName, "", "", "", "", "", "", "", "", "",
+            "", professorName, "", "", "", "", "", "", "");
+    }
+}

src/test/resources/application.yml

@@ -0,0 +1,20 @@
+spring:
+  datasource:
+    driver-class-name: org.h2.Driver
+    url: 'jdbc:h2:mem:test'
+    username: sa
+
+  h2:
+    console:
+      enabled: true
+      path: /h2-console
+
+  jpa:
+    database-platform: org.hibernate.dialect.H2Dialect
+    hibernate:
+      ddl-auto: create-drop
+    properties:
+      hibernate:
+        dialect: org.hibernate.dialect.H2Dialect
+        format_sql: true
+        show_sql: true