Group all checker which only check the value of one field

src/main/java/net/sf/jabref/logic/integrity/AbbreviationChecker.java

@@ -1,34 +1,17 @@
 package net.sf.jabref.logic.integrity;
 
-import java.util.Collections;
-import java.util.List;
 import java.util.Optional;
 
-import net.sf.jabref.logic.integrity.IntegrityCheck.Checker;
 import net.sf.jabref.logic.l10n.Localization;
-import net.sf.jabref.model.entry.BibEntry;
 
-public class AbbreviationChecker implements Checker {
-
-    private final String field;
-
-
-    public AbbreviationChecker(String field) {
-        this.field = field;
-    }
+public class AbbreviationChecker implements ValueChecker {
 
     @Override
-    public List<IntegrityMessage> check(BibEntry entry) {
-        Optional<String> value = entry.getField(field);
-        if (!value.isPresent()) {
-            return Collections.emptyList();
-        }
-
-        if (value.get().contains(".")) {
-            return Collections
-                    .singletonList(new IntegrityMessage(Localization.lang("abbreviation detected"), entry, field));
+    public Optional<String> checkValue(String value) {
+        if (value.contains(".")) {
+            return Optional.of(Localization.lang("abbreviation detected"));
         }
 
-        return Collections.emptyList();
+        return Optional.empty();
     }
 }

src/main/java/net/sf/jabref/logic/integrity/BooktitleChecker.java

@@ -1,30 +1,18 @@
 package net.sf.jabref.logic.integrity;
 
-import java.util.Collections;
-import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 
-import net.sf.jabref.logic.integrity.IntegrityCheck.Checker;
 import net.sf.jabref.logic.l10n.Localization;
-import net.sf.jabref.model.entry.BibEntry;
-import net.sf.jabref.model.entry.FieldName;
 
-public class BooktitleChecker implements Checker {
+public class BooktitleChecker implements ValueChecker {
 
     @Override
-    public List<IntegrityMessage> check(BibEntry entry) {
-        String field = FieldName.BOOKTITLE;
-        Optional<String> value = entry.getField(field);
-        if (!value.isPresent()) {
-            return Collections.emptyList();
+    public Optional<String> checkValue(String value) {
+        if (value.toLowerCase(Locale.ENGLISH).endsWith("conference on")) {
+            return Optional.of(Localization.lang("booktitle ends with 'conference on'"));
         }
 
-        if (value.get().toLowerCase(Locale.ENGLISH).endsWith("conference on")) {
-            return Collections.singletonList(
-                    new IntegrityMessage(Localization.lang("booktitle ends with 'conference on'"), entry, field));
-        }
-
-        return Collections.emptyList();
+        return Optional.empty();
     }
 }

src/main/java/net/sf/jabref/logic/integrity/BracketChecker.java

@@ -1,50 +1,31 @@
 package net.sf.jabref.logic.integrity;
 
-import java.util.Collections;
-import java.util.List;
 import java.util.Optional;
 
-import net.sf.jabref.logic.integrity.IntegrityCheck.Checker;
 import net.sf.jabref.logic.l10n.Localization;
-import net.sf.jabref.model.entry.BibEntry;
 
-public class BracketChecker implements Checker {
-
-    private final String field;
-
-
-    public BracketChecker(String field) {
-        this.field = field;
-    }
+public class BracketChecker implements ValueChecker {
 
     @Override
-    public List<IntegrityMessage> check(BibEntry entry) {
-        Optional<String> value = entry.getField(field);
-        if (!value.isPresent()) {
-            return Collections.emptyList();
-        }
-
+    public Optional<String> checkValue(String value) {
         // metaphor: integer-based stack (push + / pop -)
         int counter = 0;
-        for (char a : value.get().trim().toCharArray()) {
+        for (char a : value.trim().toCharArray()) {
             if (a == '{') {
                 counter++;
             } else if (a == '}') {
                 if (counter == 0) {
-                    return Collections.singletonList(
-                            new IntegrityMessage(Localization.lang("unexpected closing curly bracket"), entry, field));
+                    return Optional.of(Localization.lang("unexpected closing curly bracket"));
                 } else {
                     counter--;
                 }
             }
         }
 
         if (counter > 0) {
-            return Collections.singletonList(
-                    new IntegrityMessage(Localization.lang("unexpected opening curly bracket"), entry, field));
+            return Optional.of(Localization.lang("unexpected opening curly bracket"));
         }
 
-        return Collections.emptyList();
+        return Optional.empty();
     }
-
 }

src/main/java/net/sf/jabref/logic/integrity/DOIValidityChecker.java

@@ -1,22 +1,18 @@
 package net.sf.jabref.logic.integrity;
 
-import java.util.Collections;
-import java.util.List;
+import java.util.Optional;
 
-import net.sf.jabref.logic.integrity.IntegrityCheck.Checker;
 import net.sf.jabref.logic.l10n.Localization;
 import net.sf.jabref.logic.util.DOI;
-import net.sf.jabref.model.entry.BibEntry;
-import net.sf.jabref.model.entry.FieldName;
 
-public class DOIValidityChecker implements Checker {
+public class DOIValidityChecker implements ValueChecker {
 
     @Override
-    public List<IntegrityMessage> check(BibEntry entry) {
-        final String field = FieldName.DOI;
-        return entry.getField(field)
-                .filter(d -> !DOI.isValid(d))
-                .map(d -> Collections.singletonList(new IntegrityMessage(Localization.lang("DOI %0 is invalid", d), entry, field)))
-                .orElse(Collections.emptyList());
+    public Optional<String> checkValue(String value) {
+        if (DOI.isValid(value)) {
+            return Optional.empty();
+        } else {
+            return Optional.of(Localization.lang("DOI %0 is invalid", value));
+        }
     }
 }

src/main/java/net/sf/jabref/logic/integrity/EditionChecker.java

@@ -1,19 +1,14 @@
 package net.sf.jabref.logic.integrity;
 
-import java.util.Collections;
-import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
 
-import net.sf.jabref.logic.integrity.IntegrityCheck.Checker;
 import net.sf.jabref.logic.l10n.Localization;
 import net.sf.jabref.model.database.BibDatabaseContext;
-import net.sf.jabref.model.entry.BibEntry;
-import net.sf.jabref.model.entry.FieldName;
 
-public class EditionChecker implements Checker {
+public class EditionChecker implements ValueChecker {
 
     private static final Predicate<String> FIRST_LETTER_CAPITALIZED = Pattern.compile("^[A-Z]").asPredicate();
     private static final Predicate<String> ONLY_NUMERALS_OR_LITERALS = Pattern.compile("^([0-9]+|[^0-9].+)$")
@@ -37,24 +32,17 @@ public EditionChecker(BibDatabaseContext bibDatabaseContext) {
      * This should be an ordinal, and should have the first letter capitalized.
      */
     @Override
-    public List<IntegrityMessage> check(BibEntry entry) {
-        Optional<String> value = entry.getField(FieldName.EDITION);
-        if (!value.isPresent()) {
-            return Collections.emptyList();
-        }
-
+    public Optional<String> checkValue(String value) {
         //BibLaTeX
-        if (bibDatabaseContextEdition.isBiblatexMode() && !ONLY_NUMERALS_OR_LITERALS.test(value.get().trim())) {
-            return Collections.singletonList(new IntegrityMessage(
-                    Localization.lang("should contain an integer or a literal"), entry, FieldName.EDITION));
+        if (bibDatabaseContextEdition.isBiblatexMode() && !ONLY_NUMERALS_OR_LITERALS.test(value.trim())) {
+            return Optional.of(Localization.lang("should contain an integer or a literal"));
         }
 
         //BibTeX
-        if (!bibDatabaseContextEdition.isBiblatexMode() && !FIRST_LETTER_CAPITALIZED.test(value.get().trim())) {
-            return Collections.singletonList(new IntegrityMessage(
-                    Localization.lang("should have the first letter capitalized"), entry, FieldName.EDITION));
+        if (!bibDatabaseContextEdition.isBiblatexMode() && !FIRST_LETTER_CAPITALIZED.test(value.trim())) {
+            return Optional.of(Localization.lang("should have the first letter capitalized"));
         }
 
-        return Collections.emptyList();
+        return Optional.empty();
     }
 }

src/main/java/net/sf/jabref/logic/integrity/FieldChecker.java

@@ -0,0 +1,29 @@
+package net.sf.jabref.logic.integrity;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+import net.sf.jabref.logic.util.OptionalUtil;
+import net.sf.jabref.model.entry.BibEntry;
+
+public class FieldChecker implements IntegrityCheck.Checker {
+    protected final String field;
+    private final ValueChecker checker;
+
+    public FieldChecker(String field, ValueChecker checker) {
+        this.field = field;
+        this.checker = Objects.requireNonNull(checker);
+    }
+
+    @Override
+    public List<IntegrityMessage> check(BibEntry entry) {
+        Optional<String> value = entry.getField(field);
+        if (!value.isPresent()) {
+            return Collections.emptyList();
+        }
+
+        return OptionalUtil.toList(checker.checkValue(value.get()).map(message -> new IntegrityMessage(message, entry, field)));
+    }
+}

src/main/java/net/sf/jabref/logic/integrity/FieldCheckers.java

@@ -0,0 +1,51 @@
+package net.sf.jabref.logic.integrity;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import net.sf.jabref.model.database.BibDatabaseContext;
+import net.sf.jabref.model.entry.FieldName;
+import net.sf.jabref.model.entry.InternalBibtexFields;
+import net.sf.jabref.model.metadata.FileDirectoryPreferences;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.Multimap;
+
+public class FieldCheckers {
+    static List<FieldChecker> getAll(BibDatabaseContext databaseContext, FileDirectoryPreferences fileDirectoryPreferences) {
+        return getAllMap(databaseContext, fileDirectoryPreferences)
+                .entries().stream()
+                .map(pair -> new FieldChecker(pair.getKey(), pair.getValue()))
+                .collect(Collectors.toList());
+    }
+
+    private static Multimap<String, ValueChecker> getAllMap(BibDatabaseContext databaseContext, FileDirectoryPreferences fileDirectoryPreferences) {
+        ArrayListMultimap<String, ValueChecker> fieldCheckers = ArrayListMultimap.create(50, 10);
+
+        for (String field : InternalBibtexFields.getJournalNameFields()) {
+            fieldCheckers.put(field, new AbbreviationChecker());
+        }
+        for (String field : InternalBibtexFields.getBookNameFields()) {
+            fieldCheckers.put(field, new AbbreviationChecker());
+        }
+        for (String field : InternalBibtexFields.getPersonNameFields()) {
+            fieldCheckers.put(field, new PersonNamesChecker());
+        }
+        fieldCheckers.put(FieldName.BOOKTITLE, new BooktitleChecker());
+        fieldCheckers.put(FieldName.TITLE, new BracketChecker());
+        fieldCheckers.put(FieldName.TITLE, new TitleChecker(databaseContext));
+        fieldCheckers.put(FieldName.DOI, new DOIValidityChecker());
+        fieldCheckers.put(FieldName.EDITION, new EditionChecker(databaseContext));
+        fieldCheckers.put(FieldName.FILE, new FileChecker(databaseContext, fileDirectoryPreferences));
+        fieldCheckers.put(FieldName.HOWPUBLISHED, new HowPublishedChecker(databaseContext));
+        fieldCheckers.put(FieldName.ISBN, new ISBNChecker());
+        fieldCheckers.put(FieldName.ISSN, new ISSNChecker());
+        fieldCheckers.put(FieldName.MONTH, new MonthChecker(databaseContext));
+        fieldCheckers.put(FieldName.NOTE, new NoteChecker(databaseContext));
+        fieldCheckers.put(FieldName.PAGES, new PagesChecker(databaseContext));
+        fieldCheckers.put(FieldName.URL, new UrlChecker());
+        fieldCheckers.put(FieldName.YEAR, new YearChecker());
+
+        return fieldCheckers;
+    }
+}