Fix for issue 7633: Unable to download arXiv pdfs if Title contains c…

…urly brackets (#7652)

* fix 7633

* Update CHANGELOG.md

* Update ArXivTest.java

* Update CHANGELOG.md

* Update ArXivTest.java

* Update StringUtil.java

* Update ArXiv.java

* add white space

* update checkstyle

CHANGELOG.md

@@ -76,6 +76,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where opening BibTex file (doubleclick) from Folder with spaces not working. [#6487](https://github.com/JabRef/jabref/issues/6487)
 - We fixed an issue with saving large `.bib` files [#7265](https://github.com/JabRef/jabref/issues/7265)
 - We fixed an issue with very large page numbers [#7590](https://github.com/JabRef/jabref/issues/7590)
+- We fixed an issue where the article title with curly brackets fails to download the arXiv link (pdf file). [#7633](https://github.com/JabRef/jabref/issues/7633)
 
 ### Removed
 

src/main/java/org/jabref/logic/importer/fetcher/ArXiv.java

@@ -136,7 +136,7 @@ private List<ArXivEntry> searchForEntries(BibEntry entry) throws FetcherExceptio
             query = "doi:" + doi.get();
         } else {
             Optional<String> authorQuery = entry.getField(StandardField.AUTHOR).map(author -> "au:" + author);
-            Optional<String> titleQuery = entry.getField(StandardField.TITLE).map(title -> "ti:" + title);
+            Optional<String> titleQuery = entry.getField(StandardField.TITLE).map(title -> "ti:" + StringUtil.ignoreCurlyBracket(title));
             query = OptionalUtil.toList(authorQuery, titleQuery).stream().collect(Collectors.joining("+AND+"));
         }
 
@@ -146,7 +146,7 @@ private List<ArXivEntry> searchForEntries(BibEntry entry) throws FetcherExceptio
             // Check if entry is a match
             StringSimilarity match = new StringSimilarity();
             String arxivTitle = arxivEntry.get().title.orElse("");
-            String entryTitle = entry.getField(StandardField.TITLE).orElse("");
+            String entryTitle = StringUtil.ignoreCurlyBracket(entry.getField(StandardField.TITLE).orElse(""));
 
             if (match.isSimilar(arxivTitle, entryTitle)) {
                 return OptionalUtil.toList(arxivEntry);

src/main/java/org/jabref/model/strings/StringUtil.java

@@ -735,4 +735,8 @@ public static boolean containsIgnoreCase(String text, String searchString) {
     public static String substringBetween(String str, String open, String close) {
         return StringUtils.substringBetween(str, open, close);
     }
+
+    public static String ignoreCurlyBracket(String title) {
+        return isNotBlank(title) ? title.replace("{", "").replace("}", "") : title;
+    }
 }

src/test/java/org/jabref/logic/importer/fetcher/ArXivTest.java

@@ -95,6 +95,13 @@ void findFullTextByTitle() throws IOException {
         assertEquals(Optional.of(new URL("http://arxiv.org/pdf/cond-mat/0406246v1")), fetcher.findFullText(entry));
     }
 
+    @Test
+    void findFullTextByTitleWithCurlyBracket() throws IOException {
+        entry.setField(StandardField.TITLE, "Machine versus {Human} {Attention} in {Deep} {Reinforcement} {Learning} {Tasks}");
+
+        assertEquals(Optional.of(new URL("https://arxiv.org/pdf/2010.15942v2")), fetcher.findFullText(entry));
+    }
+
     @Test
     void findFullTextByTitleAndPartOfAuthor() throws IOException {
         entry.setField(StandardField.TITLE, "Pause Point Spectra in DNA Constant-Force Unzipping");
@@ -103,6 +110,14 @@ void findFullTextByTitleAndPartOfAuthor() throws IOException {
         assertEquals(Optional.of(new URL("http://arxiv.org/pdf/cond-mat/0406246v1")), fetcher.findFullText(entry));
     }
 
+    @Test
+    void findFullTextByTitleWithCurlyBracketAndPartOfAuthor() throws IOException {
+        entry.setField(StandardField.TITLE, "Machine versus {Human} {Attention} in {Deep} {Reinforcement} {Learning} {Tasks}");
+        entry.setField(StandardField.AUTHOR, "Zhang, Ruohan and Guo");
+
+        assertEquals(Optional.of(new URL("https://arxiv.org/pdf/2010.15942v2")), fetcher.findFullText(entry));
+    }
+
     @Test
     void notFindFullTextByUnknownDOI() throws IOException {
         entry.setField(StandardField.DOI, "10.1529/unknown");