更改：附件返回绝对地址

app/views/api/v1/attachments/_simple_detail.json.jbuilder

@@ -2,6 +2,6 @@ json.id attachment.id
 json.title attachment.title
 json.filesize number_to_human_size(attachment.filesize)
 json.is_pdf attachment.is_pdf?
-json.url attachment.is_pdf? ? download_url(attachment,disposition:"inline") : download_url(attachment)
+json.url Rails.application.config_for(:configuration)['platform_url'] + (attachment.is_pdf? ? download_url(attachment,disposition:"inline") : download_url(attachment)).to_s
 json.created_on attachment.created_on.strftime("%Y-%m-%d %H:%M")
 json.content_type attachment.content_type