fix: 메일 전송 객체 매번 생성,, #3

src/main/java/com/nexters/covid/letter/api/MailController.java

@@ -3,7 +3,6 @@
 import com.nexters.covid.base.BaseResponse;
 import com.nexters.covid.letter.service.MailService;
 import java.io.UnsupportedEncodingException;
-import java.util.concurrent.ExecutionException;
 import javax.mail.MessagingException;
 import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -18,7 +17,7 @@ public class MailController {
 
   @GetMapping("/mail/{sendOptionId}")
   public BaseResponse<?> sendLetters(@PathVariable("sendOptionId") Long sendOptionId)
-      throws MessagingException, ExecutionException, InterruptedException {
+      throws MessagingException, UnsupportedEncodingException {
     mailService.sendLetters(sendOptionId);
     return new BaseResponse<>(200, 0, "", null);
   }

src/main/java/com/nexters/covid/letter/service/MailAsyncService.java

@@ -7,6 +7,7 @@
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.concurrent.CompletableFuture;
+import javax.mail.MessagingException;
 import javax.mail.internet.MimeMessage;
 import lombok.RequiredArgsConstructor;
 import org.springframework.mail.javamail.JavaMailSender;
@@ -19,17 +20,20 @@
 @RequiredArgsConstructor
 public class MailAsyncService {
 
+  private final JavaMailSender javaMailSender;
   private final LetterRepository letterRepository;
 
   @Async("threadPoolTaskExecutor")
   @Transactional
-  public CompletableFuture<Boolean> sendLetter(JavaMailSender javaMailSender, MimeMessage msg,
-      MimeMessageHelper msgHelper, Letter letter, LetterText text) {
+  public CompletableFuture<Boolean> sendLetter(Letter letter, LetterText text)
+      throws MessagingException {
+
+    MimeMessage msg = javaMailSender.createMimeMessage();
+    MimeMessageHelper msgHelper = new MimeMessageHelper(msg, true, "UTF-8");
     try {
-      msgHelper.setFrom(letter.getEmail(), "안녕, 나야");
+      msgHelper.setFrom("[email protected]", "안녕, 나야");
       msgHelper.setTo(letter.getLetterTo());
       msgHelper.setSubject(generateLetterTitle(letter.getCreatedDate()));
-      msgHelper.setText(generateLetterTitle(letter.getCreatedDate()));
       msgHelper.setText(text.generateLetterBody(letter), true);
 
       javaMailSender.send(msg);

src/main/java/com/nexters/covid/letter/service/MailService.java

@@ -1,26 +1,21 @@
 package com.nexters.covid.letter.service;
 
-import com.nexters.covid.base.Constant;
 import com.nexters.covid.base.LetterText;
 import com.nexters.covid.letter.domain.Letter;
 import com.nexters.covid.letter.domain.LetterRepository;
 import com.nexters.covid.letter.domain.State;
 import java.util.List;
-import java.util.concurrent.ExecutionException;
 import javax.mail.MessagingException;
-import javax.mail.internet.MimeMessage;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.mail.javamail.JavaMailSender;
-import org.springframework.mail.javamail.MimeMessageHelper;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
 public class MailService {
 
-  private final JavaMailSender javaMailSender;
   private final LetterRepository letterRepository;
   private final MailAsyncService mailAsyncService;
 
@@ -39,12 +34,10 @@ public List<Letter> findLettersByOptionIdAndState(Long sendOptionId) {
   public void sendLetters(Long sendOptionId)
       throws MessagingException {
     List<Letter> letters = findLettersByOptionIdAndState(sendOptionId);
-    MimeMessage msg = javaMailSender.createMimeMessage();
-    MimeMessageHelper msgHelper = new MimeMessageHelper(msg, true, "UTF-8");
     LetterText text = new LetterText(letterUrl, stickerUrl);
 
     for (Letter letter : letters) {
-      mailAsyncService.sendLetter(javaMailSender, msg, msgHelper, letter, text);
+      mailAsyncService.sendLetter(letter, text);
     }
   }
 }