use an explicitly typed object for attachment references

Author: SirCotare

src/main/java/it/aboutbits/springboot/emailservice/lib/AttachmentDataSource.java

@@ -5,7 +5,7 @@
 import java.io.InputStream;
 
 public interface AttachmentDataSource {
-    InputStream getAttachmentPayload(String reference) throws AttachmentException;
+    InputStream getAttachmentPayload(AttachmentReference reference) throws AttachmentException;
 
-    void releaseAttachment(String reference) throws AttachmentException;
+    void releaseAttachment(AttachmentReference reference) throws AttachmentException;
 }

src/main/java/it/aboutbits/springboot/emailservice/lib/AttachmentReference.java

@@ -0,0 +1,11 @@
+package it.aboutbits.springboot.emailservice.lib;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.NonNull;
+
+public record AttachmentReference(
+        @NonNull
+        @NotBlank
+        String value
+) {
+}

src/main/java/it/aboutbits/springboot/emailservice/lib/EmailAttachmentDto.java

@@ -11,6 +11,6 @@ public record EmailAttachmentDto(
 
         String contentType,
 
-        String reference
+        AttachmentReference reference
 ) {
 }

src/main/java/it/aboutbits/springboot/emailservice/lib/application/EmailParameter.java

@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.emailservice.lib.application;
 
+import it.aboutbits.springboot.emailservice.lib.AttachmentReference;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotEmpty;
 import lombok.Builder;
@@ -48,8 +49,7 @@ public record Email(
         @Builder
         public record Attachment(
                 @NonNull
-                @NotBlank
-                String reference,
+                AttachmentReference reference,
                 @NonNull
                 @NotBlank
                 String fileName,

src/main/java/it/aboutbits/springboot/emailservice/lib/application/ManageEmail.java

@@ -2,6 +2,7 @@
 
 
 import it.aboutbits.springboot.emailservice.lib.AttachmentDataSource;
+import it.aboutbits.springboot.emailservice.lib.AttachmentReference;
 import it.aboutbits.springboot.emailservice.lib.EmailDto;
 import it.aboutbits.springboot.emailservice.lib.EmailState;
 import it.aboutbits.springboot.emailservice.lib.exception.AttachmentException;
@@ -61,7 +62,7 @@ public EmailDto schedule(@NonNull @Valid EmailParameter parameter) {
                 .map(a -> {
                     var attachment = new EmailAttachment();
                     attachment.setEmail(email);
-                    attachment.setReference(a.reference());
+                    attachment.setReference(a.reference().value());
                     attachment.setContentType(a.contentType());
                     attachment.setFileName(a.fileName());
                     return attachment;
@@ -105,7 +106,7 @@ Email send(Email email) {
 
     private void cleanupAttachments(final Email email) throws AttachmentException {
         for (var attachment : email.getAttachments()) {
-            attachmentDataSource.releaseAttachment(attachment.getReference());
+            attachmentDataSource.releaseAttachment(new AttachmentReference(attachment.getReference()));
         }
     }
 
@@ -138,7 +139,7 @@ private void sendMail(String fromAddress, String fromName, List<String> recipien
 
         if (!attachments.isEmpty()) {
             for (var attachment : attachments) {
-                var payload = attachmentDataSource.getAttachmentPayload(attachment.getReference());
+                var payload = attachmentDataSource.getAttachmentPayload(new AttachmentReference(attachment.getReference()));
                 helper.addAttachment(attachment.getFileName(), new ByteArrayResource(payload.readAllBytes()));
                 payload.close();
             }

src/main/java/it/aboutbits/springboot/emailservice/lib/application/UnavailableAttachmentDataSource.java

@@ -1,18 +1,19 @@
 package it.aboutbits.springboot.emailservice.lib.application;
 
 import it.aboutbits.springboot.emailservice.lib.AttachmentDataSource;
+import it.aboutbits.springboot.emailservice.lib.AttachmentReference;
 import it.aboutbits.springboot.emailservice.lib.exception.AttachmentException;
 
 import java.io.InputStream;
 
 public final class UnavailableAttachmentDataSource implements AttachmentDataSource {
     @Override
-    public InputStream getAttachmentPayload(final String reference) throws AttachmentException {
+    public InputStream getAttachmentPayload(AttachmentReference reference) throws AttachmentException {
         throw new AttachmentException("attachments not available");
     }
 
     @Override
-    public void releaseAttachment(final String reference) throws AttachmentException {
+    public void releaseAttachment(AttachmentReference reference) throws AttachmentException {
         throw new AttachmentException("attachments not available");
     }
 }