refactor: AWS BCC 메일 발송 기능 리펙터링

src/main/kotlin/apply/application/mail/MailService.kt

@@ -3,6 +3,7 @@ package apply.application.mail
 import apply.application.ApplicationProperties
 import apply.application.ResetPasswordRequest
 import apply.domain.user.User
+import org.springframework.boot.autoconfigure.mail.MailProperties
 import org.springframework.core.io.ByteArrayResource
 import org.springframework.scheduling.annotation.Async
 import org.springframework.stereotype.Service
@@ -13,7 +14,8 @@ import org.thymeleaf.spring5.ISpringTemplateEngine
 class MailService(
     private val applicationProperties: ApplicationProperties,
     private val templateEngine: ISpringTemplateEngine,
-    private val mailSender: MailSender
+    private val mailSender: MailSender,
+    private val mailProperties: MailProperties
 ) {
     val MAIL_SENDING_UNIT = 50
 
@@ -70,6 +72,7 @@ class MailService(
 
     @Async
     fun sendMailsByBCC(request: MailData, files: Map<String, ByteArrayResource>) {
+        request.recipients.plus(mailProperties.username)
         for (targetMailsPart in request.recipients.chunked(MAIL_SENDING_UNIT)) {
             mailSender.sendBcc(targetMailsPart.toTypedArray(), request.subject, request.body, files)
         }

src/main/kotlin/apply/infra/mail/AwsMailSender.kt

@@ -10,24 +10,10 @@ import com.amazonaws.services.simpleemail.model.Body
 import com.amazonaws.services.simpleemail.model.Content
 import com.amazonaws.services.simpleemail.model.Destination
 import com.amazonaws.services.simpleemail.model.Message
-import com.amazonaws.services.simpleemail.model.RawMessage
 import com.amazonaws.services.simpleemail.model.SendEmailRequest
-import com.amazonaws.services.simpleemail.model.SendRawEmailRequest
 import org.springframework.boot.autoconfigure.mail.MailProperties
 import org.springframework.core.io.ByteArrayResource
 import org.springframework.stereotype.Component
-import java.io.ByteArrayOutputStream
-import java.nio.ByteBuffer
-import java.util.Properties
-import javax.activation.DataHandler
-import javax.activation.DataSource
-import javax.activation.MimetypesFileTypeMap
-import javax.mail.Session
-import javax.mail.internet.InternetAddress
-import javax.mail.internet.MimeBodyPart
-import javax.mail.internet.MimeMessage
-import javax.mail.internet.MimeMultipart
-import javax.mail.util.ByteArrayDataSource
 import javax.mail.Message as javaxMessage
 
 @Component
@@ -66,77 +52,20 @@ class AwsMailSender(
         body: String,
         files: Map<String, ByteArrayResource>
     ) {
+        val multipartMimeMessage = message {
+            this.subject = subject
+            this.userName = mailProperties.username
+            this.recipient = Recipient(javaxMessage.RecipientType.BCC, toAddresses)
+            this.body = body
+            this.files = files
+        }.build()
 
-        var message: MimeMessage? = null
-        val session = Session.getDefaultInstance(Properties())
-        // Create a new MimeMessage object.
-        message = MimeMessage(session)
-        // Add subject, from and to lines.
-        message.setSubject(subject, "UTF-8")
-        message.setFrom(InternetAddress(mailProperties.username)) // SENDER, [email protected]
-        message.setRecipients(javaxMessage.RecipientType.TO, toAddresses.map { InternetAddress(it) }.toTypedArray())
-        // Create a multipart/alternative child container.
-        val msgBody = MimeMultipart("alternative")
-        val wrap = MimeBodyPart()
-        val textPart = MimeBodyPart()
-        textPart.setContent(body, "text/plain; charset=UTF-8")
-
-        // val htmlPart = MimeBodyPart()
-        // htmlPart.setContent(bodyHTML, "text/html; charset=UTF-8") // BODY HTML 은 제외, 제외해도 돌아가는가?
-        // msgBody.addBodyPart(htmlPart)
-        msgBody.addBodyPart(textPart)
-        wrap.setContent(msgBody)
-        // Create a multipart/mixed parent container.
-        val msg = MimeMultipart("mixed")
-        // Add the parent container to the message.
-        message.setContent(msg)
-        // Add the multipart/alternative part to the message.
-        msg.addBodyPart(wrap)
-        // Define the attachment
-
-        // val fds: DataSource = ByteArrayDataSource(attachment, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet") <- 레퍼런스
-        for ((fileName, fileData) in files) {
-            val att = MimeBodyPart()
-            val fds: DataSource = ByteArrayDataSource(
-                fileData.byteArray,
-                MimetypesFileTypeMap().getContentType(fileName)
-            )
-            // val fds: DataSource = FileDataSource("C:\\Users\\kirin\\Desktop\\의문점 1.png")
-
-            att.dataHandler = DataHandler(fds)
-            att.fileName = fileName
-            // val reportName = "PhotoReport.xls" <- 이 항목이 있는걸로 보아 att.fileName으로 이름을 붙여줄 수 있는듯
-            // att.fileName = reportName
-            msg.addBodyPart(att)
-        }
-
-        // Add the attachment to the message.
-
-        // Try to send the email.
+        val rawEmailRequest = multipartMimeMessage.getRawEmailRequest()
         try {
-            // println("Attempting to send an email through Amazon SES " + "using the AWS SDK for Java...")
-            // Print the raw email content on the console
-            // Print the raw email content on the console
-            val out = System.out
-            message.writeTo(out)
-            // Send the email.
-            // Send the email.
-            val outputStream = ByteArrayOutputStream()
-            message.writeTo(outputStream)
-            val rawMessage = RawMessage(ByteBuffer.wrap(outputStream.toByteArray()))
-
-            val rawEmailRequest = SendRawEmailRequest(rawMessage)
-            // .withConfigurationSetName("ConfigSet") // <- 기본값
-
             client.sendRawEmail(rawEmailRequest)
-            // println("Email sent!")
-            // Display an error if something goes wrong.
         } catch (ex: Exception) {
-            println("Email Failed")
-            println("Error message: ${ex.message}}")
             ex.printStackTrace()
         }
-        println("Email sent with attachment")
     }
 
     private fun createContent(data: String): Content {

src/main/kotlin/apply/infra/mail/MultipartMimeMessage.kt

@@ -0,0 +1,100 @@
+package apply.infra.mail
+
+import com.amazonaws.services.simpleemail.model.RawMessage
+import com.amazonaws.services.simpleemail.model.SendRawEmailRequest
+import org.springframework.core.io.ByteArrayResource
+import java.io.ByteArrayOutputStream
+import java.nio.ByteBuffer
+import java.util.Properties
+import javax.activation.DataHandler
+import javax.activation.DataSource
+import javax.activation.MimetypesFileTypeMap
+import javax.mail.Message
+import javax.mail.Session
+import javax.mail.internet.InternetAddress
+import javax.mail.internet.MimeBodyPart
+import javax.mail.internet.MimeMessage
+import javax.mail.internet.MimeMultipart
+import javax.mail.util.ByteArrayDataSource
+
+data class Recipient(val recipientType: Message.RecipientType, val toAddresses: Array<String>)
+
+class MultipartMimeMessage(session: Session, private val mimeMixedPart: MimeMultipart) {
+    val message: MimeMessage = MimeMessage(session)
+
+    fun setSubject(subject: String) {
+        message.setSubject(subject, "UTF-8")
+    }
+
+    fun setFrom(userName: String) {
+        message.setFrom(InternetAddress(userName))
+    }
+
+    fun setRecipient(recipient: Recipient) {
+        message.setRecipients(recipient.recipientType, recipient.toAddresses.map { InternetAddress(it) }.toTypedArray())
+    }
+
+    fun addBody(body: String) {
+        val messageBody = MimeMultipart("alternative")
+        val wrap = MimeBodyPart()
+        val textPart = MimeBodyPart()
+        textPart.setContent(body, "text/plain; charset=UTF-8")
+        messageBody.addBodyPart(textPart)
+        wrap.setContent(messageBody)
+        message.setContent(mimeMixedPart)
+        mimeMixedPart.addBodyPart(wrap)
+    }
+
+    fun addAttachment(files: Map<String, ByteArrayResource>) {
+        for ((fileName, fileData) in files) {
+            val att = MimeBodyPart()
+            val fds: DataSource = ByteArrayDataSource(
+                fileData.byteArray,
+                findMimeContentTypeByFileName(fileName)
+            )
+            att.dataHandler = DataHandler(fds)
+            att.fileName = fileName
+            mimeMixedPart.addBodyPart(att)
+        }
+    }
+
+    private fun findMimeContentTypeByFileName(fileName: String): String {
+        return MimetypesFileTypeMap().getContentType(fileName)
+            ?: throw IllegalArgumentException("잘못된 확장자입니다.")
+    }
+
+    fun getRawEmailRequest(): SendRawEmailRequest {
+        val rawMessage = createRawMessage(message)
+        return SendRawEmailRequest(rawMessage)
+    }
+
+    private fun createRawMessage(message: MimeMessage): RawMessage {
+        val outputStream = ByteArrayOutputStream()
+        message.writeTo(outputStream)
+        return RawMessage(ByteBuffer.wrap(outputStream.toByteArray()))
+    }
+}
+
+data class MultipartMimeMessageBuilder(
+    var session: Session = Session.getDefaultInstance(Properties()),
+    var mimeMixedPart: MimeMultipart = MimeMultipart("mixed"),
+    var subject: String = "",
+    var userName: String = "",
+    var recipient: Recipient? = null,
+    var body: String = "",
+    var files: Map<String, ByteArrayResource>? = null
+) {
+    fun build(): MultipartMimeMessage {
+        return MultipartMimeMessage(session, mimeMixedPart).apply {
+            setSubject(subject)
+            setFrom(userName)
+            setRecipient(recipient!!)
+            addBody(body)
+            addAttachment(files!!)
+        }
+    }
+}
+
+fun message(lambda: MultipartMimeMessageBuilder.() -> Unit): MultipartMimeMessageBuilder {
+    return MultipartMimeMessageBuilder().apply(lambda)
+}