Fix downloading in case of circular redirect

CHANGELOG.md

@@ -27,7 +27,6 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 
 
-
 ### Fixed
 
 - The tab "deprecated fields" is shown in biblatex-mode only. [#7757](https://github.com/JabRef/jabref/issues/7757)
@@ -37,6 +36,8 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where extra curly braces in some fields would trigger an exception when selecting the entry or doing an integrity check [#9475](https://github.com/JabRef/jabref/issues/9475), [#9503](https://github.com/JabRef/jabref/issues/9503)
 - We fixed an issue where entering a date in the format "YYYY/MM" in the entry editor date field caused an exception. [#9492](https://github.com/JabRef/jabref/issues/9492)
 - For portable versions, the `.deb` file now works on plain debian again. [#9472](https://github.com/JabRef/jabref/issues/9472)
+- We fixed an issue where the download of linked online files failed after an import of entries for certain urls [#9518](https://github.com/JabRef/jabref/issues/9518)
+
 
 ### Removed
 

src/main/java/org/jabref/gui/fieldeditors/LinkedFileViewModel.java

@@ -490,13 +490,17 @@ public boolean checkSSLHandshake(URLDownload urlDownload) {
             if (ex.getCause() instanceof javax.net.ssl.SSLHandshakeException) {
                 if (dialogService.showConfirmationDialogAndWait(Localization.lang("Download file"),
                         Localization.lang("Unable to find valid certification path to requested target(%0), download anyway?",
-                                urlDownload.getSource().toString()))) {
+                                          urlDownload.getSource().toString()))) {
                     return true;
                 } else {
                     dialogService.notify(Localization.lang("Download operation canceled."));
+                    return false;
                 }
+            } else {
+                LOGGER.error("Error while checking if the file can be downloaded", ex);
+                dialogService.notify(Localization.lang("Error downloading"));
+                return false;
             }
-            return false;
         }
         return true;
     }

src/main/java/org/jabref/logic/net/URLDownload.java

@@ -43,10 +43,11 @@
 import org.jabref.logic.importer.FetcherClientException;
 import org.jabref.logic.importer.FetcherServerException;
 import org.jabref.logic.util.io.FileUtil;
-import org.jabref.model.util.FileHelper;
 
 import kong.unirest.Unirest;
 import kong.unirest.UnirestException;
+import kong.unirest.apache.ApacheClient;
+import org.apache.http.client.config.RequestConfig;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -66,7 +67,7 @@
  */
 public class URLDownload {
 
-    public static final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:79.0) Gecko/20100101 Firefox/79.0";
+    public static final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36";
     private static final Logger LOGGER = LoggerFactory.getLogger(URLDownload.class);
     private static final Duration DEFAULT_CONNECT_TIMEOUT = Duration.ofSeconds(30);
 
@@ -202,7 +203,14 @@ public String getMimeType() {
      * @return the status code of the response
      */
     public boolean canBeReached() throws UnirestException {
-        Unirest.config().setDefaultHeader("User-Agent", "Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6");
+
+       // Set a custom Apache Client Builder to be able to allow circular redirects, otherwise downloads from springer might not work
+        Unirest.config().httpClient(new ApacheClient.Builder()
+                                    .withRequestConfig((c, r) -> RequestConfig.custom()
+                                                       .setCircularRedirectsAllowed(true)
+                                                       .build()));
+
+        Unirest.config().setDefaultHeader("User-Agent", USER_AGENT);
 
         int statusCode = Unirest.head(source.toString()).asString().getStatus();
         return (statusCode >= 200) && (statusCode < 300);
@@ -333,7 +341,7 @@ public Path toTemporaryFile() throws IOException {
         // Take everything after the last '/' as name + extension
         String fileNameWithExtension = sourcePath.substring(sourcePath.lastIndexOf('/') + 1);
         String fileName = "jabref-" + FileUtil.getBaseName(fileNameWithExtension);
-        String extension = "." + FileHelper.getFileExtension(fileNameWithExtension).orElse("tmp");
+        String extension = "." + FileUtil.getFileExtension(fileNameWithExtension).orElse("tmp");
 
         // Create temporary file and download to it
         Path file = Files.createTempFile(fileName, extension);