Refactor BibtexParser

src/jmh/java/net/sf/jabref/benchmarks/Benchmarks.java

@@ -73,10 +73,8 @@ public void init() throws Exception {
 
     @Benchmark
     public ParserResult parse() throws IOException {
-        StringReader bibtexStringReader = new StringReader(bibtexString);
-        BibtexParser parser = new BibtexParser(bibtexStringReader,
-                Globals.prefs.getImportFormatPreferences());
-        return parser.parse();
+        BibtexParser parser = new BibtexParser(Globals.prefs.getImportFormatPreferences());
+        return parser.parse(new StringReader(bibtexString));
     }
 
     @Benchmark

src/main/java/net/sf/jabref/cli/CrossrefFetcherEvaluator.java

@@ -27,8 +27,8 @@ public class CrossrefFetcherEvaluator {
     public static void main(String[] args) throws IOException, InterruptedException {
         Globals.prefs = JabRefPreferences.getInstance();
         try (FileReader reader = new FileReader(args[0])) {
-            BibtexParser parser = new BibtexParser(reader, Globals.prefs.getImportFormatPreferences());
-            ParserResult result = parser.parse();
+            BibtexParser parser = new BibtexParser(Globals.prefs.getImportFormatPreferences());
+            ParserResult result = parser.parse(reader);
             BibDatabase db = result.getDatabase();
 
             List<BibEntry> entries = db.getEntries();

src/main/java/net/sf/jabref/gui/ClipBoardManager.java

@@ -91,9 +91,8 @@ public List<BibEntry> extractBibEntriesFromClipboard() {
                     entry.ifPresent(result::add);
                 } else {
                     // parse bibtex string
-                    BibtexParser bp = new BibtexParser(new StringReader(data),
-                            Globals.prefs.getImportFormatPreferences());
-                    BibDatabase db = bp.parse().getDatabase();
+                    BibtexParser bp = new BibtexParser(Globals.prefs.getImportFormatPreferences());
+                    BibDatabase db = bp.parse(new StringReader(data)).getDatabase();
                     LOGGER.info("Parsed " + db.getEntryCount() + " entries from clipboard text");
                     if (db.hasEntries()) {
                         result = db.getEntries();

src/main/java/net/sf/jabref/gui/entryeditor/EntryEditor.java

@@ -759,11 +759,9 @@ public synchronized void switchTo(BibEntry switchEntry) {
     }
 
     private boolean storeSource() {
-        BibtexParser bibtexParser = new BibtexParser(new StringReader(source.getText()),
-                Globals.prefs.getImportFormatPreferences());
-
+        BibtexParser bibtexParser = new BibtexParser(Globals.prefs.getImportFormatPreferences());
         try {
-            ParserResult parserResult = bibtexParser.parse();
+            ParserResult parserResult = bibtexParser.parse(new StringReader(source.getText()));
             BibDatabase database = parserResult.getDatabase();
 
             if (database.getEntryCount() > 1) {

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

@@ -242,9 +242,8 @@ private String getCitationsFromUrl(String urlQuery, Map<String, JLabel> ids) thr
     private BibEntry downloadEntry(String link) throws IOException {
         try {
             String s = new URLDownload(link).downloadToString(StandardCharsets.UTF_8);
-            BibtexParser bp = new BibtexParser(new StringReader(s),
-                    Globals.prefs.getImportFormatPreferences());
-            ParserResult pr = bp.parse();
+            BibtexParser bp = new BibtexParser(Globals.prefs.getImportFormatPreferences());
+            ParserResult pr = bp.parse(new StringReader(s));
             if ((pr != null) && (pr.getDatabase() != null)) {
                 Collection<BibEntry> entries = pr.getDatabase().getEntries();
                 if (entries.size() == 1) {

src/main/java/net/sf/jabref/logic/importer/SearchBasedParserFetcher.java

@@ -17,6 +17,7 @@
 
 package net.sf.jabref.logic.importer;
 
+import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
@@ -53,8 +54,8 @@ default List<BibEntry> performSearch(String query) throws FetcherException {
             return Collections.emptyList();
         }
 
-        try (InputStream is = getQueryURL(query).openStream()) {
-            return getParser().parseEntries(is);
+        try (InputStream stream = new BufferedInputStream(getQueryURL(query).openStream())) {
+            return getParser().parseEntries(stream);
         } catch (URISyntaxException e) {
             throw new FetcherException("Search URI is malformed", e);
         } catch (IOException e) {

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

@@ -1,13 +1,11 @@
 package net.sf.jabref.logic.importer.fetcher;
 
 import java.io.IOException;
-import java.io.StringReader;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.Optional;
 
 import net.sf.jabref.logic.importer.ImportFormatPreferences;
-import net.sf.jabref.logic.importer.ParserResult;
 import net.sf.jabref.logic.importer.fileformat.BibtexParser;
 import net.sf.jabref.logic.net.URLDownload;
 import net.sf.jabref.model.entry.BibEntry;
@@ -39,14 +37,7 @@ public static Optional<BibEntry> getEntry(String entryUrl, ImportFormatPreferenc
 
             URL url = new URL(BibsonomyScraper.BIBSONOMY_SCRAPER + cleanURL + BibsonomyScraper.BIBSONOMY_SCRAPER_POST);
             String bibtex = new URLDownload(url).downloadToString(StandardCharsets.UTF_8);
-            BibtexParser bp = new BibtexParser(new StringReader(bibtex), importFormatPreferences);
-            ParserResult pr = bp.parse();
-            if ((pr != null) && pr.getDatabase().hasEntries()) {
-                return Optional.of(pr.getDatabase().getEntries().iterator().next());
-            } else {
-                return Optional.empty();
-            }
-
+            return BibtexParser.singleFromString(bibtex, importFormatPreferences);
         } catch (IOException ex) {
             LOGGER.warn("Could not download entry", ex);
             return Optional.empty();

src/main/java/net/sf/jabref/logic/importer/fileformat/BibtexParser.java

@@ -1,9 +1,14 @@
 package net.sf.jabref.logic.importer.fileformat;
 
+import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.io.PushbackReader;
 import java.io.Reader;
 import java.io.StringReader;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Deque;
@@ -18,6 +23,8 @@
 import net.sf.jabref.logic.bibtex.FieldContentParser;
 import net.sf.jabref.logic.exporter.SavePreferences;
 import net.sf.jabref.logic.importer.ImportFormatPreferences;
+import net.sf.jabref.logic.importer.Parser;
+import net.sf.jabref.logic.importer.ParserException;
 import net.sf.jabref.logic.importer.ParserResult;
 import net.sf.jabref.logic.importer.util.ParseException;
 import net.sf.jabref.logic.l10n.Localization;
@@ -50,11 +57,11 @@
  * <p>
  * Can be used stand-alone.
  */
-public class BibtexParser {
+public class BibtexParser implements Parser {
 
     private static final Log LOGGER = LogFactory.getLog(BibtexParser.class);
 
-    private final PushbackReader pushbackReader;
+    private PushbackReader pushbackReader;
     private BibDatabase database;
     private Map<String, EntryType> entryTypes;
     private boolean eof;
@@ -66,11 +73,9 @@ public class BibtexParser {
     private final ImportFormatPreferences importFormatPreferences;
 
 
-    public BibtexParser(Reader in, ImportFormatPreferences importFormatPreferences) {
-        Objects.requireNonNull(in);
+    public BibtexParser(ImportFormatPreferences importFormatPreferences) {
         this.importFormatPreferences = Objects.requireNonNull(importFormatPreferences);
         fieldContentParser = new FieldContentParser(importFormatPreferences.getFieldContentParserPreferences());
-        pushbackReader = new PushbackReader(in, BibtexParser.LOOKAHEAD);
     }
 
     /**
@@ -79,9 +84,9 @@ public BibtexParser(Reader in, ImportFormatPreferences importFormatPreferences)
      * @param in the Reader to read from
      * @throws IOException
      */
+    @Deprecated // inline this method
     public static ParserResult parse(Reader in, ImportFormatPreferences importFormatPreferences) throws IOException {
-        BibtexParser parser = new BibtexParser(in, importFormatPreferences);
-        return parser.parse();
+        return new BibtexParser(importFormatPreferences).parse(in);
     }
 
     /**
@@ -92,10 +97,10 @@ public static ParserResult parse(Reader in, ImportFormatPreferences importFormat
      */
     public static List<BibEntry> fromString(String bibtexString, ImportFormatPreferences importFormatPreferences) {
         StringReader reader = new StringReader(bibtexString);
-        BibtexParser parser = new BibtexParser(reader, importFormatPreferences);
+        BibtexParser parser = new BibtexParser(importFormatPreferences);
 
         try {
-            return parser.parse().getDatabase().getEntries();
+            return parser.parse(reader).getDatabase().getEntries();
         } catch (Exception e) {
             LOGGER.warn("BibtexParser.fromString(String): " + e.getMessage(), e);
             return Collections.emptyList();
@@ -119,6 +124,16 @@ public static Optional<BibEntry> singleFromString(String bibtexString,
         return Optional.of(entries.iterator().next());
     }
 
+    @Override
+    public List<BibEntry> parseEntries(InputStream inputStream) throws ParserException {
+        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
+        try {
+            return parse(reader).getDatabase().getEntries();
+        } catch (IOException e) {
+            throw new ParserException(e);
+        }
+    }
+
     /**
      * Will parse the BibTex-Data found when reading from reader. Ignores any encoding supplied in the file by
      * "Encoding: myEncoding".
@@ -130,11 +145,10 @@ public static Optional<BibEntry> singleFromString(String bibtexString,
      * @return ParserResult
      * @throws IOException
      */
-    public ParserResult parse() throws IOException {
-        // If we already parsed this, just return it.
-        if (parserResult != null) {
-            return parserResult;
-        }
+    public ParserResult parse(Reader in) throws IOException {
+        Objects.requireNonNull(in);
+        pushbackReader = new PushbackReader(in, BibtexParser.LOOKAHEAD);
+
         // Bibtex related contents.
         initializeParserResult();
 

src/test/java/net/sf/jabref/BibtexTestData.java

@@ -17,17 +17,16 @@ public static BibEntry getBibtexEntry(ImportFormatPreferences importFormatPrefer
     }
 
     public static BibDatabase getBibtexDatabase(ImportFormatPreferences importFormatPreferences) throws IOException {
-        StringReader reader = new StringReader(
-                "@ARTICLE{HipKro03,\n" + "  author = {Eric von Hippel and Georg von Krogh},\n"
+        String article = "@ARTICLE{HipKro03,\n" + "  author = {Eric von Hippel and Georg von Krogh},\n"
                         + "  title = {Open Source Software and the \"Private-Collective\" Innovation Model: Issues for Organization Science},\n"
                         + "  journal = {Organization Science},\n" + "  year = {2003},\n" + "  volume = {14},\n"
                         + "  pages = {209--223},\n" + "  number = {2},\n"
                         + "  address = {Institute for Operations Research and the Management Sciences (INFORMS), Linthicum, Maryland, USA},\n"
                         + "  doi = {http://dx.doi.org/10.1287/orsc.14.2.209.14992}," + "\n" + "  issn = {1526-5455},"
-                        + "\n" + "  publisher = {INFORMS}\n" + "}");
+                        + "\n" + "  publisher = {INFORMS}\n" + "}";
 
-        BibtexParser parser = new BibtexParser(reader, importFormatPreferences);
-        ParserResult result = parser.parse();
+        BibtexParser parser = new BibtexParser(importFormatPreferences);
+        ParserResult result = parser.parse(new StringReader(article));
 
         return result.getDatabase();
     }

src/test/java/net/sf/jabref/logic/bibtex/BibEntryAssert.java

@@ -62,9 +62,8 @@ public static void assertEquals(Class<?> clazz, String resourceName, List<BibEnt
     private static List<BibEntry> getListFromInputStream(InputStream is) throws IOException {
         ParserResult result;
         try (Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
-            BibtexParser parser = new BibtexParser(reader,
-                    JabRefPreferences.getInstance().getImportFormatPreferences());
-            result = parser.parse();
+            BibtexParser parser = new BibtexParser(JabRefPreferences.getInstance().getImportFormatPreferences());
+            result = parser.parse(reader);
         }
         Assert.assertNotNull(result);
         Assert.assertFalse(result.isNullResult());

src/test/java/net/sf/jabref/logic/importer/fileformat/BibtexParserTest.java

@@ -60,8 +60,8 @@ public static void setUp() {
 
     @SuppressWarnings("unused")
     @Test(expected = NullPointerException.class)
-    public void initalizationWithNullThrowsNullPointerException() {
-        new BibtexParser(null, importFormatPreferences);
+    public void parseWithNullThrowsNullPointerException() throws Exception {
+        new BibtexParser(importFormatPreferences).parse(null);
     }
 
     @Test
@@ -126,15 +126,6 @@ public void singleFromStringReturnsNullIfNoEntryRecognized() {
         assertEquals(Optional.empty(), parsed);
     }
 
-    @Test
-    public void parseTwoTimesReturnsSameResult() throws IOException {
-        BibtexParser parser = new BibtexParser(new StringReader("@article{test,author={Ed von Test}}"),
-                importFormatPreferences);
-        ParserResult result = parser.parse();
-
-        assertEquals(result, parser.parse());
-    }
-
     @Test
     public void parseRecognizesEntry() throws IOException {
         ParserResult result = BibtexParser.parse(new StringReader("@article{test,author={Ed von Test}}"),
@@ -1394,18 +1385,18 @@ public void parseTrimsWhitespaceInEpilogueAfterEntry() throws IOException {
 
     @Test
     public void parseRecognizesSaveActionsAfterEntry() throws IOException {
-        BibtexParser parser = new BibtexParser(
+        BibtexParser parser = new BibtexParser(importFormatPreferences);
+
+        ParserResult parserResult = parser.parse(
                 new StringReader("@InProceedings{6055279,\n" + "  Title                    = {Educational session 1},\n"
                         + "  Booktitle                = {Custom Integrated Circuits Conference (CICC), 2011 IEEE},\n"
                         + "  Year                     = {2011},\n" + "  Month                    = {Sept},\n"
                         + "  Pages                    = {1-7},\n"
                         + "  Abstract                 = {Start of the above-titled section of the conference proceedings record.},\n"
                         + "  DOI                      = {10.1109/CICC.2011.6055279},\n"
                         + "  ISSN                     = {0886-5930}\n" + "}\n" + "\n"
-                        + "@comment{jabref-meta: saveActions:enabled;title[lower_case]}"),
-                importFormatPreferences);
-
-        ParserResult parserResult = parser.parse();
+                        + "@comment{jabref-meta: saveActions:enabled;title[lower_case]}")
+                );
 
         FieldFormatterCleanups saveActions = parserResult.getMetaData().getSaveActions().get();
 
@@ -1416,11 +1407,10 @@ public void parseRecognizesSaveActionsAfterEntry() throws IOException {
 
     @Test
     public void integrationTestSaveActions() throws IOException {
-        BibtexParser parser = new BibtexParser(
-                new StringReader("@comment{jabref-meta: saveActions:enabled;title[lower_case]}"),
-                importFormatPreferences);
+        BibtexParser parser = new BibtexParser(importFormatPreferences);
 
-        ParserResult parserResult = parser.parse();
+        ParserResult parserResult = parser.parse(
+                new StringReader("@comment{jabref-meta: saveActions:enabled;title[lower_case]}"));
         FieldFormatterCleanups saveActions = parserResult.getMetaData().getSaveActions().get();
 
         assertTrue(saveActions.isEnabled());

src/test/java/net/sf/jabref/logic/util/io/RegExpFileSearchTests.java

@@ -2,20 +2,15 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
-import net.sf.jabref.logic.importer.ParserResult;
-import net.sf.jabref.logic.importer.fileformat.BibtexParser;
 import net.sf.jabref.model.database.BibDatabase;
 import net.sf.jabref.model.entry.BibEntry;
 import net.sf.jabref.model.entry.BibtexEntryTypes;
-import net.sf.jabref.preferences.JabRefPreferences;
 
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -30,25 +25,23 @@ public class RegExpFileSearchTests {
     @Before
     public void setUp() throws IOException {
 
-        StringReader reader = new StringReader(
-                "@ARTICLE{HipKro03," + "\n" + "  author = {Eric von Hippel and Georg von Krogh}," + "\n"
-                        + "  title = {Open Source Software and the \"Private-Collective\" Innovation Model: Issues for Organization Science},"
-                        + "\n" + "  journal = {Organization Science}," + "\n" + "  year = {2003}," + "\n"
-                        + "  volume = {14}," + "\n" + "  pages = {209--223}," + "\n" + "  number = {2}," + "\n"
-                        + "  address = {Institute for Operations Research and the Management Sciences (INFORMS), Linthicum, Maryland, USA},"
-                        + "\n" + "  doi = {http://dx.doi.org/10.1287/orsc.14.2.209.14992}," + "\n"
-                        + "  issn = {1526-5455}," + "\n" + "  publisher = {INFORMS}" + "\n" + "}");
-
-        BibtexParser parser = new BibtexParser(reader, JabRefPreferences.getInstance().getImportFormatPreferences());
-        ParserResult result = null;
-
-        result = parser.parse();
-
-        database = result.getDatabase();
-        entry = database.getEntryByKey("HipKro03").get();
-
-        Assert.assertNotNull(database);
-        Assert.assertNotNull(entry);
+        entry = new BibEntry();
+        entry.setType(BibtexEntryTypes.ARTICLE);
+        entry.setCiteKey("HipKro03");
+        entry.setField("author", "Eric von Hippel and Georg von Krogh");
+        entry.setField("title", "Open Source Software and the \"Private-Collective\" Innovation Model: Issues for Organization Science");
+        entry.setField("journal", "Organization Science");
+        entry.setField("year", "2003");
+        entry.setField("volume", "14");
+        entry.setField("pages", "209--223");
+        entry.setField("number", "2");
+        entry.setField("address", "Institute for Operations Research and the Management Sciences (INFORMS), Linthicum, Maryland, USA");
+        entry.setField("doi", "http://dx.doi.org/10.1287/orsc.14.2.209.14992");
+        entry.setField("issn", "1526-5455");
+        entry.setField("publisher", "INFORMS");
+
+        database = new BibDatabase();
+        database.insertEntry(entry);
     }
 
     @Test