fix: 메일 발송 비동기 처리 #3

src/main/java/com/nexters/covid/CovidApplication.java

@@ -3,7 +3,9 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
+import org.springframework.scheduling.annotation.EnableAsync;
 
+@EnableAsync
 @EnableJpaAuditing
 @SpringBootApplication
 public class CovidApplication {

src/main/java/com/nexters/covid/config/SpringAsyncConfig.java

@@ -0,0 +1,34 @@
+package com.nexters.covid.config;
+
+import java.util.concurrent.Executor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurer;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@Configuration
+@EnableAsync
+public class SpringAsyncConfig implements AsyncConfigurer {
+
+  @Value("${async.pool.core_pool_size}")
+  private Integer corePoolSize;
+  @Value("${async.pool.max_pool_size}")
+  private Integer maxPoolSize;
+  @Value("${async.pool.queue_capacity}")
+  private Integer queueCapacity;
+  @Value("${async.pool.prefix_name}")
+  private String prefixName;
+
+  @Bean(name = "threadPoolTaskExecutor")
+  public Executor threadPoolTaskExecutor() {
+    ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+    taskExecutor.setCorePoolSize(corePoolSize);
+    taskExecutor.setMaxPoolSize(maxPoolSize);
+    taskExecutor.setMaxPoolSize(queueCapacity);
+    taskExecutor.setThreadNamePrefix(prefixName);
+    taskExecutor.initialize();
+    return taskExecutor;
+  }
+}

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

@@ -3,6 +3,7 @@
 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;
@@ -17,7 +18,7 @@ public class MailController {
 
   @GetMapping("/mail/{sendOptionId}")
   public BaseResponse<?> sendLetters(@PathVariable("sendOptionId") Long sendOptionId)
-      throws MessagingException, UnsupportedEncodingException {
+      throws MessagingException, ExecutionException, InterruptedException {
     mailService.sendLetters(sendOptionId);
     return new BaseResponse<>(200, 0, "", null);
   }

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

@@ -0,0 +1,47 @@
+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 java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.concurrent.CompletableFuture;
+import javax.mail.internet.MimeMessage;
+import lombok.RequiredArgsConstructor;
+import org.springframework.mail.javamail.JavaMailSender;
+import org.springframework.mail.javamail.MimeMessageHelper;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class MailAsyncService {
+
+  private final LetterRepository letterRepository;
+
+  @Async("threadPoolTaskExecutor")
+  @Transactional
+  public CompletableFuture<Boolean> sendLetter(JavaMailSender javaMailSender, MimeMessage msg,
+      MimeMessageHelper msgHelper, Letter letter, LetterText text) {
+    try {
+      msgHelper.setFrom(letter.getEmail(), "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);
+    } catch (Exception e) {
+      return CompletableFuture.completedFuture(Boolean.FALSE);
+    }
+    letterRepository.updateLetterState(letter.getEncryptedId());
+    return CompletableFuture.completedFuture(Boolean.TRUE);
+  }
+
+  private String generateLetterTitle(LocalDateTime createdDate) {
+    return createdDate.format(DateTimeFormatter.ofPattern(
+        Constant.LETTER_TITLE_FORMAT));
+  }
+}

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

@@ -5,10 +5,8 @@
 import com.nexters.covid.letter.domain.Letter;
 import com.nexters.covid.letter.domain.LetterRepository;
 import com.nexters.covid.letter.domain.State;
-import java.io.UnsupportedEncodingException;
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 import javax.mail.MessagingException;
 import javax.mail.internet.MimeMessage;
 import lombok.RequiredArgsConstructor;
@@ -18,12 +16,13 @@
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
-@RequiredArgsConstructor
 @Service
+@RequiredArgsConstructor
 public class MailService {
 
   private final JavaMailSender javaMailSender;
   private final LetterRepository letterRepository;
+  private final MailAsyncService mailAsyncService;
 
   @Value("${prefix.letter.url}")
   private String letterUrl;
@@ -38,25 +37,14 @@ public List<Letter> findLettersByOptionIdAndState(Long sendOptionId) {
 
   @Transactional
   public void sendLetters(Long sendOptionId)
-      throws MessagingException, UnsupportedEncodingException {
+      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) {
-      msgHelper.setFrom(letter.getEmail(), "안녕, 나야");
-      msgHelper.setTo(letter.getLetterTo());
-      msgHelper.setSubject(generateLetterTitle(letter.getCreatedDate()));
-      msgHelper.setText(text.generateLetterBody(letter), true);
-
-      javaMailSender.send(msg);
-      letterRepository.updateLetterState(letter.getEncryptedId());
+      mailAsyncService.sendLetter(javaMailSender, msg, msgHelper, letter, text);
     }
   }
-
-  private String generateLetterTitle(LocalDateTime createdDate) {
-    return createdDate.format(DateTimeFormatter.ofPattern(
-        Constant.LETTER_TITLE_FORMAT));
-  }
 }