EmailAttachment.EmailAttachment.DataSource.ByteArrayDataSource and then calls EmailAttachmentBuilder.content(DataSource).ByteArrayDataSource and then calls EmailAttachmentBuilder.content(DataSource).null contentType.FileDataSource and then calls EmailAttachmentBuilder.content(DataSource)EmailAttachment 的构建器EmailAttachment classEmailMessage上EmailMessage.DataSource.DataSource implementation, depending on attachment source.EmailAttachment is inline.true if the attachment is embedded.true if attachment is embedded into provided message.true if it is an inline attachment."foo@bar.com" - 仅邮件地址.InternetAddress 创建地址InternetAddress 创建地址mail.smtp.starttls.required.EmailAttachmentBuilder.