[Feature/paginate email receivers] - 페이지네이션 추가 (#43)

src/main/java/gdsc/konkuk/platformcore/application/email/EmailService.java

@@ -11,8 +11,10 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
@@ -28,6 +30,11 @@ public List<EmailTask> getAllTaskAsList() {
     return emailTaskRepository.findAll();
   }
 
+  public Page<EmailTask> getAllTaskWithPage(int pageNo) {
+    Pageable pageable = PageRequest.of(pageNo, 10);
+    return emailTaskRepository.findAll(pageable);
+  }
+
   public EmailTask getTaskDetails(Long taskId) {
     return findEmailTaskById(emailTaskRepository, taskId);
   }

src/main/java/gdsc/konkuk/platformcore/controller/email/EmailController.java

@@ -19,6 +19,7 @@
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
@@ -35,6 +36,14 @@ public ResponseEntity<SuccessResponse> getAllEmailTask() {
     return ResponseEntity.ok(SuccessResponse.of(emailTasks));
   }
 
+  @GetMapping("/pages")
+  public ResponseEntity<SuccessResponse> getAllEmailTask(
+      @RequestParam(required = false, defaultValue = "0", value = "page") int pageNo
+  ) {
+    EmailTaskListResponse emailTasks = EmailTaskMapper.mapToEmailTaskPageResponse(emailService.getAllTaskWithPage(pageNo));
+    return ResponseEntity.ok(SuccessResponse.of(emailTasks));
+  }
+
   @GetMapping("/{taskId}")
   public ResponseEntity<SuccessResponse> getEmailTask(@PathVariable Long taskId) {
     EmailTaskDetailResponse emailTask = EmailTaskMapper.mapToEmailTaskDetailsResponse(emailService.getTaskDetails(taskId));

src/main/java/gdsc/konkuk/platformcore/controller/email/mapper/EmailTaskMapper.java

@@ -8,10 +8,15 @@
 import gdsc.konkuk.platformcore.domain.email.entity.EmailTask;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
+import org.springframework.data.domain.Page;
 
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class EmailTaskMapper {
 
+  public static EmailTaskListResponse mapToEmailTaskPageResponse(Page<EmailTask> emailTasks) {
+    return mapToEmailTaskListResponse(emailTasks.getContent());
+  }
+
   public static EmailTaskListResponse mapToEmailTaskListResponse(List<EmailTask> emailTasks) {
     List<SimpleEmailTaskResponse> simpleEmailTaskResponses =
       emailTasks.stream()

src/main/java/gdsc/konkuk/platformcore/domain/email/entity/EmailReceivers.java

@@ -2,6 +2,7 @@
 
 import jakarta.persistence.CollectionTable;
 import jakarta.persistence.ElementCollection;
+import jakarta.persistence.FetchType;
 import jakarta.persistence.JoinColumn;
 import java.util.HashSet;
 import java.util.Objects;
@@ -11,13 +12,15 @@
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
 
 @Embeddable
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 public class EmailReceivers {
 
-  @ElementCollection
+  @BatchSize(size = 100)
+  @ElementCollection(fetch = FetchType.LAZY)
   @CollectionTable(name = "email_receivers", joinColumns = @JoinColumn(name = "task_id"))
   Set<EmailReceiver> receivers = new HashSet<>();
 

src/main/java/gdsc/konkuk/platformcore/domain/email/repository/EmailTaskRepository.java

@@ -1,6 +1,8 @@
 package gdsc.konkuk.platformcore.domain.email.repository;
 
 import java.util.List;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import gdsc.konkuk.platformcore.domain.email.entity.EmailTask;
@@ -10,4 +12,6 @@ public interface EmailTaskRepository extends JpaRepository<EmailTask, Long> {
 
   @Query("SELECT e FROM EmailTask e WHERE e.isSent = false")
   List<EmailTask> findAllWhereNotSent();
+
+  Page<EmailTask> findAll(Pageable pageable);
 }