Step3

src/main/java/nextstep/courses/domain/Course.java

@@ -61,4 +61,8 @@ public String toString() {
                 ", updatedAt=" + updatedAt +
                 '}';
     }
+
+    public Long getId() {
+        return this.id;
+    }
 }

src/main/java/nextstep/courses/domain/CourseRepository.java

@@ -1,7 +1,7 @@
 package nextstep.courses.domain;
 
 public interface CourseRepository {
-    int save(Course course);
+    long save(Course course);
 
     Course findById(Long id);
 }

src/main/java/nextstep/courses/domain/RegisteredUsers.java

@@ -5,6 +5,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 /**
  * 수강신청한 사용자들 목록
@@ -24,4 +25,12 @@ public void add(NsUser user) {
     public int theNumberOfUsers() {
         return this.users.size();
     }
-}
+
+    public Stream<NsUser> stream() {
+        return this.users.stream();
+    }
+
+    public List<NsUser> toList() {
+        return List.copyOf(this.users);
+    }
+}

src/main/java/nextstep/courses/domain/Session.java

@@ -1,6 +1,6 @@
 package nextstep.courses.domain;
 
-import nextstep.courses.type.InfinitablePositiveInteger;
+import nextstep.courses.type.MaxRegister;
 import nextstep.courses.type.SessionDuration;
 import nextstep.courses.type.SessionState;
 import nextstep.payments.domain.Payment;
@@ -24,48 +24,49 @@ public class Session {
     private SessionImage coverImage;
     private SessionDuration duration;
 
-    private InfinitablePositiveInteger maxUserCount;
+    private MaxRegister maxUserCount;
     private int fee;
 
+
     private Session() {
 
     }
 
-    public static Session createFreeSession(Long id, Course course, SessionImage coverImage, SessionDuration duration) {
+    public static Session create(Long id, Course course, SessionState state, RegisteredUsers registeredUsers, SessionImage coverImage, SessionDuration duration, MaxRegister maxUserCount, int fee) {
         Session session = new Session();
 
         session.id = id;
         session.course = course;
-        session.state = READY;
-        session.registeredUsers = new RegisteredUsers();
+        session.state = state;
+        session.registeredUsers = registeredUsers;
         session.coverImage = coverImage;
         session.duration = duration;
-        session.maxUserCount = InfinitablePositiveInteger.infinite();
-        session.fee = 0;
+        session.maxUserCount = maxUserCount;
+        session.fee = fee;
 
         validateSession(session);
         return session;
     }
 
-    public static Session createPaidSession(Long id, Course course, SessionImage coverImage, SessionDuration duration, InfinitablePositiveInteger maxUserCount, int fee) {
-        Session session = new Session();
-
-        session.id = id;
-        session.course = course;
-        session.state = READY;
-        session.registeredUsers = new RegisteredUsers();
-        session.coverImage = coverImage;
-        session.duration = duration;
-        session.maxUserCount = maxUserCount;
-        session.fee = fee;
+    public static Session createFreeSession(Long id, Course course, SessionImage coverImage, SessionDuration duration) {
+        return Session.create(id, course, READY, new RegisteredUsers(), coverImage, duration, MaxRegister.infinite(), 0);
+    }
 
-        validateSession(session);
-        return session;
+    public static Session createPaidSession(Long id, Course course, SessionImage coverImage, SessionDuration duration, MaxRegister maxUserCount, int fee) {
+        return Session.create(id, course, READY, new RegisteredUsers(), coverImage, duration, maxUserCount, fee);
     }
 
     private static void validateSession(Session session) {
         validateFee(session.fee);
+        validateMaxUserCount(session.maxUserCount, session.fee);
     }
+
+    private static void validateMaxUserCount(MaxRegister maxUserCount, int fee) {
+        if (fee == 0 && maxUserCount.isFinite()) {
+            throw new IllegalArgumentException("무료 강의는 수강 제한 인원을 둘 수 없습니다.");
+        }
+    }
+
     private static void validateFee(int fee) {
         if (fee < 0) {
             throw new IllegalArgumentException("강의료가 음수일 수 없습니다.");
@@ -88,15 +89,15 @@ public void registerUser(NsUser user) {
     }
 
     public void registerUser(NsUser user, Payment payment) {
-        if (payment.isSameUser(user) == false) {
+        if (!payment.isSameUser(user)) {
             throw new IllegalArgumentException("지불 정보와 등록하는 유저가 일치하지 않습니다.");
         }
 
-        if (payment.isSameAmountWith(this.fee) == false) {
+        if (!payment.isSameAmountWith(this.fee)) {
             throw new IllegalArgumentException("수강료와 지불 금액이 동일하지 않습니다.");
         }
 
-        if (this.maxUserCount.isLargerThan(this.registeredUsers.theNumberOfUsers()) == false) {
+        if (!this.maxUserCount.isLargerThan(this.registeredUsers.theNumberOfUsers())) {
             throw new IllegalStateException("이 강의의 최대 등록 가능 인원에 도달했습니다. 더 이상 사용자를 추가할 수 없습니다.");
         }
 
@@ -116,6 +117,31 @@ public Long getId() {
         return this.id;
     }
 
+
+    public Course getCourse() {
+        return course;
+    }
+
+    public SessionState getState() {
+        return state;
+    }
+
+    public SessionImage getCoverImage() {
+        return coverImage;
+    }
+
+    public SessionDuration getDuration() {
+        return duration;
+    }
+
+    public MaxRegister getMaxUserCount() {
+        return maxUserCount;
+    }
+
+    public int getFee() {
+        return fee;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -141,4 +167,8 @@ public String toString() {
                 ", fee=" + fee +
                 '}';
     }
+
+    public RegisteredUsers getRegisteredUsers() {
+        return this.registeredUsers;
+    }
 }

src/main/java/nextstep/courses/domain/SessionImage.java

@@ -3,11 +3,13 @@
 import nextstep.courses.type.*;
 
 public class SessionImage {
-    private static final Capacity MAX_CAPACITY = new Capacity(1024, CapacityUnit.KB);
-    private static final Rectangle MIN_SIZE = new Rectangle(300, 200, LengthUnit.PIXEL);
+    private static final Capacity MAX_CAPACITY = new Capacity(1024);
+    private static final Rectangle MIN_SIZE = new Rectangle(300, 200);
     private static final int WIDTH_RATIO = 3;
     private static final int HEIGHT_RATIO = 2;
 
+    private String filePath;
+
     /**
      * 이미지 용량
      */
@@ -18,22 +20,32 @@ public class SessionImage {
      */
     private Rectangle size;
 
-
     private ImageExtension type;
 
-    public SessionImage(Capacity capacity, Rectangle size, ImageExtension type) {
+    public SessionImage(String filePath, Capacity capacity, Rectangle size, ImageExtension type) {
         validateCapacity(capacity);
         validateSize(size);
 
+        this.filePath = filePath;
         this.capacity = capacity;
         this.size = size;
         this.type = type;
     }
 
+    public SessionImage(String filePath, int capacity, int width, int height, ImageExtension type) {
+        this(
+                filePath,
+                new Capacity(capacity),
+                new Rectangle(width, height),
+                type
+        );
+    }
+
     public SessionImage(int capacity, int width, int height, ImageExtension type) {
         this(
-                new Capacity(capacity, CapacityUnit.KB),
-                new Rectangle(width, height, LengthUnit.PIXEL),
+                "",
+                new Capacity(capacity),
+                new Rectangle(width, height),
                 type
         );
     }
@@ -47,4 +59,19 @@ private static void validateSize(Rectangle size) {
         size.throwIfRatioIsNotTheSameWith(WIDTH_RATIO, HEIGHT_RATIO);
     }
 
-}
+    public String getFilePath() {
+        return filePath;
+    }
+
+    public Capacity getCapacity() {
+        return capacity;
+    }
+
+    public Rectangle getSize() {
+        return size;
+    }
+
+    public ImageExtension getType() {
+        return type;
+    }
+}

src/main/java/nextstep/courses/domain/SessionRepository.java

@@ -0,0 +1,7 @@
+package nextstep.courses.domain;
+
+public interface SessionRepository {
+    long save(Session session);
+
+    Session findById(Long id);
+}

src/main/java/nextstep/courses/infrastructure/JdbcCourseRepository.java

@@ -2,10 +2,16 @@
 
 import nextstep.courses.domain.Course;
 import nextstep.courses.domain.CourseRepository;
+import nextstep.courses.infrastructure.exception.DbInsertFailException;
+import nextstep.qna.CannotDeleteException;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jdbc.core.RowMapper;
+import org.springframework.jdbc.support.GeneratedKeyHolder;
+import org.springframework.jdbc.support.KeyHolder;
 import org.springframework.stereotype.Repository;
 
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.time.LocalDateTime;
 
@@ -18,9 +24,22 @@ public JdbcCourseRepository(JdbcOperations jdbcTemplate) {
     }
 
     @Override
-    public int save(Course course) {
+    public long save(Course course) {
         String sql = "insert into course (title, creator_id, created_at) values(?, ?, ?)";
-        return jdbcTemplate.update(sql, course.getTitle(), course.getCreatorId(), course.getCreatedAt());
+        KeyHolder keyHolder = new GeneratedKeyHolder();
+
+        jdbcTemplate.update(connection -> {
+            PreparedStatement ps = connection.prepareStatement(sql, new String[]{"id"});
+            ps.setString(1, course.getTitle());
+            ps.setLong(2, course.getCreatorId());
+            ps.setTimestamp(3, Timestamp.valueOf(course.getCreatedAt()));
+            return ps;
+        }, keyHolder);
+
+        if (keyHolder.getKey() == null) {
+            throw new DbInsertFailException("Course");
+        }
+        return keyHolder.getKey().longValue();
     }
 
     @Override