Check if value is already a Short DOI

CHANGELOG.md

@@ -19,6 +19,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - We moved the location of the 'Open only one instance of JabRef' preference option from "Network" to "General". [#9306](https://github.com/JabRef/jabref/issues/9306)
 - The two previews in the change resolver dialog now have their scrollbars synchronized. [#9576](https://github.com/JabRef/jabref/issues/9576).
 - We changed the setting of the keyword separator to accept a single character only. [#177](https://github.com/koppor/jabref/issues/177)
+- Short DOI formatter now checks, if the value is already formatted. If so, it returns the value instead of calling the ShortDOIService again. [#10589](https://github.com/JabRef/jabref/issues/10589)
 
 ### Fixed
 

src/main/java/org/jabref/logic/formatter/bibtexfields/ShortenDOIFormatter.java

@@ -1,6 +1,8 @@
 package org.jabref.logic.formatter.bibtexfields;
 
 import java.util.Objects;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
 
 import org.jabref.logic.cleanup.Formatter;
 import org.jabref.logic.importer.util.ShortDOIService;
@@ -14,6 +16,7 @@
 public class ShortenDOIFormatter extends Formatter {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(ShortenDOIFormatter.class);
+    private static final Predicate<String> SHORT_DOI_FORMAT = Pattern.compile("^10/[a-zA-Z0-9]+$").asPredicate();
 
     @Override
     public String getName() {
@@ -28,7 +31,7 @@ public String getKey() {
     @Override
     public String format(String value) {
         Objects.requireNonNull(value);
-        return DOI.parse(value)
+        return SHORT_DOI_FORMAT.test(value) ? value : DOI.parse(value)
                   .map(doi -> {
                       try {
                           return new ShortDOIService().getShortDOI(doi).getDOI();

src/test/java/org/jabref/logic/formatter/bibtexfields/ShortenDOIFormatterTest.java

@@ -26,4 +26,9 @@ public void formatDoi() {
     public void invalidDoiIsKept() {
         assertEquals("invalid-doi", formatter.format("invalid-doi"));
     }
+
+    @Test
+    public void shortDoi() {
+        assertEquals("10/adc", formatter.format("10/adc"));
+    }
 }