Week1 step3

src/main/java/subway/SubwayExceptionHandler.java

@@ -0,0 +1,19 @@
+package subway;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+@ControllerAdvice
+public class SubwayExceptionHandler {
+
+  @ExceptionHandler(value = IllegalArgumentException.class)
+  public ResponseEntity<Void> handleIllegalStateException(IllegalArgumentException error) {
+    return ResponseEntity.badRequest().build();
+  }
+
+  @ExceptionHandler(value = IllegalStateException.class)
+  public ResponseEntity<Void> handleIllegalStateException(IllegalStateException error) {
+    return ResponseEntity.badRequest().build();
+  }
+}

src/main/java/subway/line/Line.java

@@ -1,11 +1,13 @@
 package subway.line;
 
-import javax.persistence.CascadeType;
+import java.util.List;
+import javax.persistence.Embedded;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
-import javax.persistence.ManyToOne;
+import subway.section.Section;
+import subway.sections.Sections;
 import subway.station.Station;
 
 @Entity
@@ -19,23 +21,15 @@ public class Line {
 
   private String color;
 
-  @ManyToOne(cascade = CascadeType.ALL)
-  private Station upStation; // 상행역
-
-  @ManyToOne(cascade = CascadeType.ALL)
-  private Station downStation; // 하행역
-
-  private Long distance;
+  @Embedded
+  private Sections sections;
 
   public Line() {}
 
-  public Line(String name, String color, Station upStation, Station downStation,
-      Long distance) {
+  public Line(String name, String color) {
     this.name = name;
     this.color = color;
-    this.upStation = upStation;
-    this.downStation = downStation;
-    this.distance = distance;
+    this.sections = new Sections();
   }
 
   public Long getId() {
@@ -46,25 +40,26 @@ public String getName() {
     return name;
   }
 
-  public Station getUpStation() {
-    return upStation;
-  }
-
-  public Station getDownStation() {
-    return downStation;
-  }
-
   public String getColor() {
     return color;
   }
 
-  public Long getDistance() {
-    return distance;
+  public List<Station> getStations() {
+    return sections.getStations();
   }
 
   public Line updateLine(String name, String color) {
     this.name = name;
     this.color = color;
     return this;
   }
+
+  public Line addSection(Section add) {
+    sections.addSection(add);
+    return this;
+  }
+
+  public void removeSection(Station downStation) {
+    sections.removeSection(downStation);
+  }
 }

src/main/java/subway/line/LineController.java

@@ -22,24 +22,17 @@ public LineController(LineService lineService) {
 
   /**
    * 새로운 지하철 노선을 추가한다.
-   * @param request LineCreateRequest
+   * @param request
    * @return 노선 생성의 결과를 반환한다.
    */
   @PostMapping("/lines")
   public ResponseEntity<LineResponse> createLine(@RequestBody LineCreateRequest request) {
-    return ResponseEntity.ok().body(lineService.saveLine(
-        request.getName(),
-        request.getColor(),
-        request.getUpStationId(),
-        request.getDownStationId(),
-        request.getDistance()
-        )
-    );
+    return ResponseEntity.ok().body(lineService.saveLine(request));
   }
 
   /**
    * 지하철의 노선을 조회한다
-   * @param id Long. 조회하려는 노선의 ID
+   * @param id 조회하려는 노선의 ID
    * @return 지하철 노선의 조회 결과 값을 반환한다.
    */
   @GetMapping("/lines/{id}")
@@ -53,7 +46,7 @@ public ResponseEntity<LineResponse> showLine(@PathVariable Long id) {
 
   /**
    * 모든 지하철의 노선을 조회한다.
-   * @return 모든 지하철 모든의 정보를 반환한다.
+   * @return 모든 지하철 노선 정보를 반환한다.
    */
   @GetMapping("/lines")
   public ResponseEntity<List<LineResponse>> showAllLines() {
@@ -62,7 +55,7 @@ public ResponseEntity<List<LineResponse>> showAllLines() {
 
   /**
    * 특정 지하철 노선의 정보를 변경한다.
-   * @param id Long. 변경하려는 지하철 노선의 ID
+   * @param id 변경하려는 지하철 노선의 ID
    * @param request
    * @return 변환된 지하철 정보를 반환한다. 존재하지 않는 지하철 노선에 대한 변경은 noContent()를 반환한다.
    */
@@ -77,7 +70,7 @@ public ResponseEntity<LineResponse> patchLine(@PathVariable Long id, @RequestBod
 
   /**
    * id에 해당하는 노선 정보를 삭제한다.
-   * @param id Long. 삭제하려는 노선의 ID
+   * @param id 삭제하려는 노선의 ID
    * @return noContent() 결과값
    */
   @DeleteMapping("/lines/{id}")

src/main/java/subway/line/LineCreateRequest.java

@@ -2,11 +2,11 @@
 
 public class LineCreateRequest {
 
-  private String name;
-  private String color;
-  private Long upStationId;
-  private Long downStationId;
-  private Long distance;
+  private final String name;
+  private final String color;
+  private final Long upStationId;
+  private final Long downStationId;
+  private final Long distance;
 
   public String getName() {
     return name;

src/main/java/subway/line/LinePatchRequest.java

@@ -1,8 +1,8 @@
 package subway.line;
 
 public class LinePatchRequest {
-  private String name;
-  private String color;
+  private final String name;
+  private final String color;
 
   public LinePatchRequest(String name, String color) {
     this.name = name;

src/main/java/subway/line/LineResponse.java

@@ -1,23 +1,31 @@
 package subway.line;
 
+import java.util.List;
+import java.util.stream.Collectors;
 import subway.station.Station;
+import subway.station.StationResponse;
 
 public class LineResponse {
 
-  private Long id;
-  private String name;
-  private String color;
-  private Station upStation;
-  private Station downStation;
-  private Long distance;
+  private final Long id;
+  private final String name;
+  private final String color;
+  private final List<StationResponse> stations;
 
-  public LineResponse(Long id, String name, String color, Station upStation, Station downStation, Long distance) {
+  public LineResponse(Long id, String name, String color, List<Station> stations) {
     this.id = id;
     this.name = name;
     this.color = color;
-    this.upStation = upStation;
-    this.downStation = downStation;
-    this.distance = distance;
+    this.stations = stations.stream().map(s -> new StationResponse(s.getId(), s.getName())).collect(Collectors.toList());
+  }
+
+  public static LineResponse from(Line line) {
+    return new LineResponse(
+        line.getId(),
+        line.getName(),
+        line.getColor(),
+        line.getStations()
+    );
   }
 
   public Long getId() {
@@ -32,15 +40,7 @@ public String getColor() {
     return color;
   }
 
-  public Station getUpStation() {
-    return upStation;
-  }
-
-  public Station getDownStation() {
-    return downStation;
-  }
-
-  public Long getDistance() {
-    return distance;
+  public List<StationResponse> getStations() {
+    return stations;
   }
 }

src/main/java/subway/line/LineService.java

@@ -5,37 +5,44 @@
 import java.util.stream.Collectors;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
+import subway.section.Section;
+import subway.section.SectionCreateRequest;
+import subway.section.SectionRepository;
+import subway.section.SectionResponse;
 import subway.station.Station;
-import subway.station.StationRepository;
+import subway.station.StationService;
 
 @Service
 public class LineService {
 
   private final LineRepository lineRepository;
-  private final StationRepository stationRepository;
+  private final StationService stationService;
+  private final SectionRepository sectionRepository;
 
-  public LineService(LineRepository repository, StationRepository stationRepository) {
+  public LineService(LineRepository repository, StationService stationService, SectionRepository sectionRepository) {
     this.lineRepository = repository;
-    this.stationRepository = stationRepository;
+    this.stationService = stationService;
+    this.sectionRepository = sectionRepository;
   }
 
   @Transactional
-  public LineResponse saveLine(String name, String color, Long upStationId, Long downStationId, Long distance) {
-    Optional<Station> inbound = stationRepository.findById(upStationId);
-    Optional<Station> outbound = stationRepository.findById(downStationId);
-    Line created = lineRepository.save(new Line(name, color, inbound.get(), outbound.get(), distance));
-    return createServiceResponse(created);
+  public LineResponse saveLine(LineCreateRequest request) {
+    Station upStation = stationService.findById(request.getUpStationId());
+    Station downStation = stationService.findById(request.getDownStationId());
+
+    Line created = lineRepository.save(new Line(request.getName(), request.getColor()));
+    createSection(created.getId(), new SectionCreateRequest(upStation.getId(), downStation.getId(), request.getDistance()));
+
+    return LineResponse.from(created);
   }
 
   public Optional<LineResponse> showLine(Long id) {
-    Optional<Line> optionalLine = lineRepository.findById(id);
-
-    return optionalLine.map(this::createServiceResponse);
+    return lineRepository.findById(id).map(LineResponse::from);
   }
 
   public List<LineResponse> showLines() {
     return lineRepository.findAll().stream()
-        .map(this::createServiceResponse)
+        .map(LineResponse::from)
         .collect(Collectors.toList());
   }
 
@@ -47,11 +54,25 @@ public Optional<LineResponse> updateLine(Long id, String name, String color) {
     Optional<Line> optionalLine = lineRepository.findById(id);
 
     return optionalLine.map(line -> line.updateLine(name, color))
-        .map(lineRepository::save)
-        .map(this::createServiceResponse);
+        .map(line -> LineResponse.from(lineRepository.save(line)));
+  }
+
+  @Transactional
+  public SectionResponse createSection(Long lineId, SectionCreateRequest request) {
+    Station upStation = stationService.findById(request.getUpStationId());
+    Station downStation = stationService.findById(request.getDownStationId());
+    Line line = lineRepository.findById(lineId).orElseThrow(IllegalArgumentException::new);
+
+    Section created = sectionRepository.save(new Section(upStation, downStation, request.getDistance()));
+
+    lineRepository.save(line.addSection(created));
+
+    return SectionResponse.from(created);
   }
 
-  private LineResponse createServiceResponse(Line line) {
-    return new LineResponse(line.getId(), line.getName(), line.getColor(), line.getUpStation(), line.getDownStation(), line.getDistance());
+  public void removeSection(Long lineId, Long downStationId) {
+    Line line = lineRepository.findById(lineId).orElseThrow(IllegalArgumentException::new);
+    Station station = stationService.findById(downStationId);
+    line.removeSection(station);
   }
 }

src/main/java/subway/section/Section.java

@@ -0,0 +1,58 @@
+package subway.section;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+import subway.station.Station;
+
+@Entity
+public class Section {
+
+  @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
+  private Long id;
+
+  @ManyToOne
+  private Station upStation;
+
+  @ManyToOne
+  private Station downStation;
+
+  private Long distance;
+
+  public Long getId() {
+    return id;
+  }
+
+  // 상행역
+  public Station getUpStation() {
+    return upStation;
+  }
+
+  // 하행역
+  public Station getDownStation() {
+    return downStation;
+  }
+
+  public Long getDistance() {
+    return distance;
+  }
+
+  public Section() {}
+
+  public Section(Station upStation, Station downStation, Long distance) {
+    this.upStation = upStation;
+    this.downStation = downStation;
+    this.distance = distance;
+  }
+
+  @Override
+  public String toString() {
+    return String.format("[Section id : %d, upStationId : %d, downStationId: %d]",
+        id,
+        upStation.getId(),
+        downStation.getId()
+    );
+  }
+}