mEDRA DOI fetcher implementation.

CHANGELOG.md

@@ -11,6 +11,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 ### Added
 
+- We added a new fetcher to enable users to search mEDRA DOIs [#6602](https://github.com/JabRef/jabref/issues/6602)
 - We added a new fetcher to enable users to search "[Collection of Computer Science Bibliographies](https://liinwww.ira.uka.de/bibliography/index.html)". [#6638](https://github.com/JabRef/jabref/issues/6638)
 - We added default values for delimiters in Add Subgroup window [#6624](https://github.com/JabRef/jabref/issues/6624)
 - We improved responsiveness of general fields specification dialog window. [#6643](https://github.com/JabRef/jabref/issues/6604)

src/main/java/org/jabref/logic/importer/IdBasedParserFetcher.java

@@ -31,7 +31,7 @@ public interface IdBasedParserFetcher extends IdBasedFetcher {
      *
      * @param identifier the ID
      */
-    URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException;
+    URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException;
 
     /**
      * Returns the parser used to convert the response to a list of {@link BibEntry}.
@@ -61,7 +61,7 @@ default Optional<BibEntry> performSearchById(String identifier) throws FetcherEx
             return Optional.empty();
         }
 
-        try (InputStream stream = new URLDownload(getURLForID(identifier)).asInputStream()) {
+        try (InputStream stream = getUrlDownload(getUrlForIdentifier(identifier)).asInputStream()) {
             List<BibEntry> fetchedEntries = getParser().parseEntries(stream);
 
             if (fetchedEntries.isEmpty()) {

src/main/java/org/jabref/logic/importer/SearchBasedParserFetcher.java

@@ -43,31 +43,20 @@ public interface SearchBasedParserFetcher extends SearchBasedFetcher {
      * {@code new FieldFormatterCleanup(StandardField.TITLE, new RemoveBracesFormatter()).cleanup(entry);}
      *
      * By default, no cleanup is done.
+     *
      * @param entry the entry to be cleaned-up
      */
     default void doPostCleanup(BibEntry entry) {
         // Do nothing by default
     }
 
-    /**
-     * Gets the {@link URLDownload} object for downloading content. Overwrite, if you need to send additional headers for the download
-     *
-     * @param query The search query
-     * @throws MalformedURLException
-     * @throws FetcherException
-     * @throws URISyntaxException
-     */
-    default URLDownload getUrlDownload(String query) throws MalformedURLException, FetcherException, URISyntaxException {
-        return new URLDownload(getURLForQuery(query));
-    }
-
     @Override
     default List<BibEntry> performSearch(String query) throws FetcherException {
         if (StringUtil.isBlank(query)) {
             return Collections.emptyList();
         }
 
-        try (InputStream stream = getUrlDownload(query).asInputStream()) {
+        try (InputStream stream = getUrlDownload(getURLForQuery(query)).asInputStream()) {
             List<BibEntry> fetchedEntries = getParser().parseEntries(stream);
 
             // Post-cleanup

src/main/java/org/jabref/logic/importer/WebFetcher.java

@@ -1,8 +1,10 @@
 package org.jabref.logic.importer;
 
+import java.net.URL;
 import java.util.Optional;
 
 import org.jabref.logic.help.HelpFile;
+import org.jabref.logic.net.URLDownload;
 
 /**
  * Searches web resources for bibliographic information.
@@ -25,4 +27,11 @@ public interface WebFetcher {
     default Optional<HelpFile> getHelpPage() {
         return Optional.empty(); // no help page by default
     }
+
+    /**
+     * Constructs an {@link URLDownload} object for downloading content based on the given URL. Overwrite, if you need to send additional headers for the download.
+     */
+    default URLDownload getUrlDownload(URL url) {
+        return new URLDownload(url);
+    }
 }

src/main/java/org/jabref/logic/importer/WebFetchers.java

@@ -29,6 +29,7 @@
 import org.jabref.logic.importer.fetcher.LibraryOfCongress;
 import org.jabref.logic.importer.fetcher.MathSciNet;
 import org.jabref.logic.importer.fetcher.MedlineFetcher;
+import org.jabref.logic.importer.fetcher.Medra;
 import org.jabref.logic.importer.fetcher.OpenAccessDoi;
 import org.jabref.logic.importer.fetcher.RfcFetcher;
 import org.jabref.logic.importer.fetcher.ScienceDirect;
@@ -123,6 +124,7 @@ public static SortedSet<IdBasedFetcher> getIdBasedFetchers(ImportFormatPreferenc
         set.add(new LibraryOfCongress(importFormatPreferences));
         set.add(new IacrEprintFetcher(importFormatPreferences));
         set.add(new RfcFetcher(importFormatPreferences));
+        set.add(new Medra());
         return set;
     }
 

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

@@ -121,7 +121,7 @@ public URL getURLForEntry(BibEntry entry) throws URISyntaxException, MalformedUR
      * @return URL which points to a search URL for given identifier
      */
     @Override
-    public URL getURLForID(String identifier) throws FetcherException, URISyntaxException, MalformedURLException {
+    public URL getUrlForIdentifier(String identifier) throws FetcherException, URISyntaxException, MalformedURLException {
         String query = "doi:\"" + identifier + "\" OR " + "bibcode:\"" + identifier + "\"";
         URIBuilder builder = new URIBuilder(API_SEARCH_URL);
         builder.addParameter("q", query);
@@ -227,7 +227,7 @@ public Optional<BibEntry> performSearchById(String identifier) throws FetcherExc
         }
 
         try {
-            List<String> bibcodes = fetchBibcodes(getURLForID(identifier));
+            List<String> bibcodes = fetchBibcodes(getUrlForIdentifier(identifier));
             List<BibEntry> fetchedEntries = performSearchByIds(bibcodes);
 
             if (fetchedEntries.isEmpty()) {

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

@@ -4,6 +4,7 @@
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 
@@ -69,31 +70,38 @@ public URL getURLForQuery(String query) throws URISyntaxException, MalformedURLE
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         URIBuilder uriBuilder = new URIBuilder(API_URL + "/" + identifier);
         return uriBuilder.build().toURL();
     }
 
     @Override
     public Parser getParser() {
         return inputStream -> {
-            JSONObject response = JsonReader.toJsonObject(inputStream).getJSONObject("message");
-
-            List<BibEntry> entries = new ArrayList<>();
-            if (response.has("items")) {
-                // Response contains a list
-                JSONArray items = response.getJSONArray("items");
-                for (int i = 0; i < items.length(); i++) {
-                    JSONObject item = items.getJSONObject(i);
-                    BibEntry entry = jsonItemToBibEntry(item);
-                    entries.add(entry);
-                }
-            } else {
+            JSONObject response = JsonReader.toJsonObject(inputStream);
+            if (response.isEmpty()) {
+                return Collections.emptyList();
+            }
+
+            response = response.getJSONObject("message");
+            if (response.isEmpty()) {
+                return Collections.emptyList();
+            }
+
+            if (!response.has("items")) {
                 // Singleton response
                 BibEntry entry = jsonItemToBibEntry(response);
-                entries.add(entry);
+                return Collections.singletonList(entry);
             }
 
+            // Response contains a list
+            JSONArray items = response.getJSONArray("items");
+            List<BibEntry> entries = new ArrayList<>(items.length());
+            for (int i = 0; i < items.length(); i++) {
+                JSONObject item = items.getJSONObject(i);
+                BibEntry entry = jsonItemToBibEntry(item);
+                entries.add(entry);
+            }
             return entries;
         };
     }

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

@@ -38,7 +38,7 @@ public Optional<HelpFile> getHelpPage() {
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         URIBuilder uriBuilder = new URIBuilder("http://www.diva-portal.org/smash/getreferences");
 
         uriBuilder.addParameter("referenceFormat", "BibTex");

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

@@ -25,9 +25,15 @@
 import org.jabref.model.util.DummyFileUpdateMonitor;
 import org.jabref.model.util.OptionalUtil;
 
+import kong.unirest.json.JSONException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class DoiFetcher implements IdBasedFetcher, EntryBasedFetcher {
     public static final String NAME = "DOI";
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(DoiFetcher.class);
+
     private final ImportFormatPreferences preferences;
 
     public DoiFetcher(ImportFormatPreferences preferences) {
@@ -47,18 +53,27 @@ public Optional<HelpFile> getHelpPage() {
     @Override
     public Optional<BibEntry> performSearchById(String identifier) throws FetcherException {
         Optional<DOI> doi = DOI.parse(identifier);
+
         try {
             if (doi.isPresent()) {
+                Optional<BibEntry> fetchedEntry;
+
+                // mEDRA does not return a parsable bibtex string
+                if (doi.get().getAgency().isPresent() && "medra".equalsIgnoreCase(doi.get().getAgency().get())) {
+                    return new Medra().performSearchById(identifier);
+                }
+
                 URL doiURL = new URL(doi.get().getURIAsASCIIString());
 
                 // BibTeX data
-                URLDownload download = new URLDownload(doiURL);
+                URLDownload download = getUrlDownload(doiURL);
                 download.addHeader("Accept", MediaTypes.APPLICATION_BIBTEX);
                 String bibtexString = download.asString();
 
                 // BibTeX entry
-                Optional<BibEntry> fetchedEntry = BibtexParser.singleFromString(bibtexString, preferences, new DummyFileUpdateMonitor());
+                fetchedEntry = BibtexParser.singleFromString(bibtexString, preferences, new DummyFileUpdateMonitor());
                 fetchedEntry.ifPresent(this::doPostCleanup);
+
                 return fetchedEntry;
             } else {
                 throw new FetcherException(Localization.lang("Invalid DOI: '%0'.", identifier));
@@ -67,6 +82,8 @@ public Optional<BibEntry> performSearchById(String identifier) throws FetcherExc
             throw new FetcherException(Localization.lang("Connection error"), e);
         } catch (ParseException e) {
             throw new FetcherException("Could not parse BibTeX entry", e);
+        } catch (JSONException e) {
+            throw new FetcherException("Could not retrieve Registration Agency", e);
         }
     }
 
@@ -84,4 +101,5 @@ public List<BibEntry> performSearch(BibEntry entry) throws FetcherException {
             return Collections.emptyList();
         }
     }
+
 }

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

@@ -54,8 +54,8 @@ public URL getURLForQuery(String query) throws URISyntaxException, MalformedURLE
     }
 
     @Override
-    public URLDownload getUrlDownload(String query) throws MalformedURLException, FetcherException, URISyntaxException {
-        URLDownload download = new URLDownload(getURLForQuery(query));
+    public URLDownload getUrlDownload(URL url) {
+        URLDownload download = new URLDownload(url);
         download.addHeader("Accept", MediaTypes.APPLICATION_BIBTEX);
         return download;
     }

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

@@ -30,7 +30,7 @@ public String getName() {
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         this.ensureThatIsbnIsValid(identifier);
         URIBuilder uriBuilder = new URIBuilder(BASE_URL);
         uriBuilder.addParameter("isbn", identifier);

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

@@ -39,7 +39,7 @@ public String getName() {
      * @return null, because the identifier is passed using form data. This method is not used.
      */
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         return null;
     }
 

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

@@ -29,7 +29,7 @@ public String getName() {
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         URIBuilder uriBuilder = new URIBuilder("https://lccn.loc.gov/" + identifier + "/mods");
         return uriBuilder.build().toURL();
     }

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

@@ -57,7 +57,7 @@ public URL getURLForEntry(BibEntry entry) throws URISyntaxException, MalformedUR
         Optional<String> mrNumberInEntry = entry.getField(StandardField.MR_NUMBER);
         if (mrNumberInEntry.isPresent()) {
             // We are lucky and already know the id, so use it instead
-            return getURLForID(mrNumberInEntry.get());
+            return getUrlForIdentifier(mrNumberInEntry.get());
         }
 
         URIBuilder uriBuilder = new URIBuilder("https://mathscinet.ams.org/mrlookup");
@@ -83,7 +83,7 @@ public URL getURLForQuery(String query) throws URISyntaxException, MalformedURLE
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         URIBuilder uriBuilder = new URIBuilder("https://mathscinet.ams.org/mathscinet/search/publications.html");
         uriBuilder.addParameter("pg1", "MR"); // search MR number
         uriBuilder.addParameter("s1", identifier); // identifier

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

@@ -135,7 +135,7 @@ public Optional<HelpFile> getHelpPage() {
     }
 
     @Override
-    public URL getURLForID(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
+    public URL getUrlForIdentifier(String identifier) throws URISyntaxException, MalformedURLException, FetcherException {
         URIBuilder uriBuilder = new URIBuilder(ID_URL);
         uriBuilder.addParameter("db", "pubmed");
         uriBuilder.addParameter("retmode", "xml");
@@ -206,7 +206,7 @@ private URL createSearchUrl(String term) throws URISyntaxException, MalformedURL
     private List<BibEntry> fetchMedline(List<String> ids) throws FetcherException {
         try {
             // Separate the IDs with a comma to search multiple entries
-            URL fetchURL = getURLForID(String.join(",", ids));
+            URL fetchURL = getUrlForIdentifier(String.join(",", ids));
             URLConnection data = fetchURL.openConnection();
             ParserResult result = new MedlineImporter().importDatabase(
                     new BufferedReader(new InputStreamReader(data.getInputStream(), StandardCharsets.UTF_8)));