Rework DBLPFetcher to new structure (#2314)

* Rework DBLPFetcher to new structure - also fixes #2311

* implement as SearchBasedParserFetcher

CHANGELOG.md

@@ -21,6 +21,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - We fixed an issue which prevented that a database was saved successfully if JabRef failed to generate new BibTeX-keys [#2285](https://github.com/JabRef/jabref/issues/2285).
 - We fixed an issue when JabRef restores its session and a shared database was used: The error message "No suitable driver found" will not appear.
 - Update check now correctly notifies about new release if development version is used. [#2298](https://github.com/JabRef/jabref/issues/2298)
+- Fixed [#2311](https://github.com/JabRef/jabref/issues/2311): The DBLP fetcher has been rewritten and is working again.
 
 ### Removed
 

src/main/java/net/sf/jabref/gui/importer/fetcher/EntryFetchers.java

@@ -9,6 +9,7 @@
 import net.sf.jabref.logic.importer.IdBasedFetcher;
 import net.sf.jabref.logic.importer.fetcher.ArXiv;
 import net.sf.jabref.logic.importer.fetcher.AstrophysicsDataSystem;
+import net.sf.jabref.logic.importer.fetcher.DBLPFetcher;
 import net.sf.jabref.logic.importer.fetcher.DiVA;
 import net.sf.jabref.logic.importer.fetcher.DoiFetcher;
 import net.sf.jabref.logic.importer.fetcher.GoogleScholar;
@@ -25,7 +26,7 @@ public class EntryFetchers {
 
     public EntryFetchers(JournalAbbreviationLoader abbreviationLoader) {
         entryFetchers.add(new CiteSeerXFetcher());
-        entryFetchers.add(new DBLPFetcher());
+        entryFetchers.add(new SearchBasedEntryFetcher(new DBLPFetcher(Globals.prefs.getImportFormatPreferences())));
         entryFetchers.add(new IEEEXploreFetcher(abbreviationLoader));
         entryFetchers.add(new INSPIREFetcher());
         // entryFetchers.add(new OAI2Fetcher()); - new arXiv fetcher in place, see below

src/main/java/net/sf/jabref/logic/importer/fetcher/DBLPFetcher.java

@@ -0,0 +1,78 @@
+package net.sf.jabref.logic.importer.fetcher;
+
+import java.net.MalformedURLException;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.Objects;
+
+import net.sf.jabref.logic.cleanup.DoiCleanup;
+import net.sf.jabref.logic.formatter.bibtexfields.ClearFormatter;
+import net.sf.jabref.logic.help.HelpFile;
+import net.sf.jabref.logic.importer.FetcherException;
+import net.sf.jabref.logic.importer.ImportFormatPreferences;
+import net.sf.jabref.logic.importer.Parser;
+import net.sf.jabref.logic.importer.SearchBasedParserFetcher;
+import net.sf.jabref.logic.importer.fileformat.BibtexParser;
+import net.sf.jabref.model.cleanup.FieldFormatterCleanup;
+import net.sf.jabref.model.entry.BibEntry;
+import net.sf.jabref.model.entry.FieldName;
+
+import org.apache.http.client.utils.URIBuilder;
+
+/**
+ * Fetches BibTeX data from DBLP (dblp.org)
+ *
+ * @see <a href="http://dblp.dagstuhl.de/faq/13501473">Basic API documentation</a>
+ */
+public class DBLPFetcher implements SearchBasedParserFetcher {
+
+    private static final String BASIC_SEARCH_URL = "http://www.dblp.org/search/api/";
+
+    private final ImportFormatPreferences importFormatPreferences;
+
+    public DBLPFetcher(ImportFormatPreferences importFormatPreferences) {
+        Objects.requireNonNull(importFormatPreferences);
+
+        this.importFormatPreferences = importFormatPreferences;
+    }
+
+    @Override
+    public URL getURLForQuery(String query) throws URISyntaxException, MalformedURLException, FetcherException {
+        URIBuilder uriBuilder = new URIBuilder(BASIC_SEARCH_URL);
+        uriBuilder.addParameter("q", query);
+        uriBuilder.addParameter("h", String.valueOf(100)); // number of hits
+        uriBuilder.addParameter("c", String.valueOf(0)); // no need for auto-completion
+        uriBuilder.addParameter("f", String.valueOf(0)); // "from", index of first hit to download
+        uriBuilder.addParameter("format", "bib1");
+
+        return uriBuilder.build().toURL();
+    }
+
+    @Override
+    public Parser getParser() {
+        return new BibtexParser(importFormatPreferences);
+    }
+
+    @Override
+    public void doPostCleanup(BibEntry entry) {
+        DoiCleanup doiCleaner = new DoiCleanup();
+
+        FieldFormatterCleanup clearTimestampFormatter = new FieldFormatterCleanup(FieldName.TIMESTAMP,
+                new ClearFormatter());
+
+        doiCleaner.cleanup(entry);
+        clearTimestampFormatter.cleanup(entry);
+
+    }
+
+    @Override
+    public String getName() {
+        return "DBLP";
+    }
+
+    @Override
+    public HelpFile getHelpPage() {
+        return HelpFile.FETCHER_DBLP;
+    }
+
+}