From 9bb4f110543b692681a1aaed456d44887720c814 Mon Sep 17 00:00:00 2001
From: Stang <pmx42@live.cn>
Date: Sat, 30 May 2020 10:21:39 +0800
Subject: [PATCH] Fix #6530

---
 .../org/jabref/logic/importer/fileformat/RisImporter.java   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/main/java/org/jabref/logic/importer/fileformat/RisImporter.java b/src/main/java/org/jabref/logic/importer/fileformat/RisImporter.java
index d22c5e8d01d..9ee8f9962c4 100644
--- a/src/main/java/org/jabref/logic/importer/fileformat/RisImporter.java
+++ b/src/main/java/org/jabref/logic/importer/fileformat/RisImporter.java
@@ -316,6 +316,12 @@ private void addDoi(Map<Field, String> hm, String val) {
         if (doi.startsWith("doi:")) {
             doi = doi.replaceAll("(?i)doi:", "").trim();
             hm.put(StandardField.DOI, doi);
+        } else {
+            String doiRegEx = "10\\.[0-9]{4,}(?:\\.[0-9]+)*/(?:(?![\"&'])\\S)+";
+            Pattern pattern = Pattern.compile(doiRegEx);
+            if (pattern.matcher(doi).matches()) {
+                hm.put(StandardField.DOI, doi);
+            }
         }
     }
 }