mark htmlBody nullable and add check

Author: J0nasMayr

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

@@ -26,6 +26,8 @@ public record EmailDto(
         List<String> recipients,
 
         String textBody,
+
+        @Nullable
         String htmlBody,
 
         Set<EmailAttachmentDto> attachments,

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

@@ -34,6 +34,8 @@ public record Email(
             List<String> recipients,
 
             String textBody,
+
+            @Nullable
             String htmlBody,
 
             @NotBlank

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

@@ -184,6 +184,7 @@ private void sendMail(
             String replyToName,
             List<String> recipients,
             String subject,
+            @Nullable
             String htmlBody,
             String plainTextBody,
             Set<EmailAttachment> attachments
@@ -203,7 +204,7 @@ private void sendMail(
             }
         }
 
-        if (!htmlBody.isBlank()) {
+        if (htmlBody != null && !htmlBody.isBlank()) {
             helper.setText(plainTextBody, htmlBody);
         } else {
             helper.setText(plainTextBody);

src/main/java/it/aboutbits/springboot/emailservice/lib/model/EmailContent.java

@@ -25,6 +25,8 @@ public record EmailContent(
         List<String> recipients,
 
         String textBody,
+
+        @Nullable
         String htmlBody
 ) {
 }