Some minor code cleanups

src/main/java/net/sf/jabref/logic/layout/format/CompositeFormat.java

@@ -16,6 +16,7 @@
 package net.sf.jabref.logic.layout.format;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import net.sf.jabref.logic.layout.LayoutFormatter;
@@ -27,14 +28,14 @@
  */
 public class CompositeFormat implements LayoutFormatter {
 
-    private List<LayoutFormatter> formatters;
+    private final List<LayoutFormatter> formatters;
 
 
     /**
      * If called with this constructor, this formatter does nothing.
      */
     public CompositeFormat() {
-        // Nothing
+        formatters = Collections.emptyList();
     }
 
     public CompositeFormat(LayoutFormatter first, LayoutFormatter second) {
@@ -48,10 +49,8 @@ public CompositeFormat(LayoutFormatter[] formatters) {
     @Override
     public String format(String fieldText) {
         String result = fieldText;
-        if (formatters != null) {
-            for (LayoutFormatter formatter : formatters) {
-                result = formatter.format(result);
-            }
+        for (LayoutFormatter formatter : formatters) {
+            result = formatter.format(result);
         }
         return result;
     }

src/main/java/net/sf/jabref/model/DuplicateCheck.java

@@ -17,6 +17,7 @@
 
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -85,31 +86,29 @@ public static boolean isDuplicate(BibEntry one, BibEntry two, BibDatabaseMode bi
         EntryType type = EntryTypes.getTypeOrDefault(one.getType(), bibDatabaseMode);
 
         // The check if they have the same required fields:
-        java.util.List<String> var = type.getRequiredFieldsFlat();
-        String[] fields = var.toArray(new String[var.size()]);
+        List<String> var = type.getRequiredFieldsFlat();
         double[] req;
-        if (fields == null) {
+        if (var == null) {
             req = new double[]{0., 0.};
         } else {
-            req = DuplicateCheck.compareFieldSet(fields, one, two);
+            req = DuplicateCheck.compareFieldSet(var, one, two);
         }
 
         if (Math.abs(req[0] - DuplicateCheck.duplicateThreshold) > DuplicateCheck.DOUBT_RANGE) {
             // Far from the threshold value, so we base our decision on the req. fields only
             return req[0] >= DuplicateCheck.duplicateThreshold;
         }
         // Close to the threshold value, so we take a look at the optional fields, if any:
-        java.util.List<String> optionalFields = type.getOptionalFields();
-        fields = optionalFields.toArray(new String[optionalFields.size()]);
-        if (fields != null) {
-            double[] opt = DuplicateCheck.compareFieldSet(fields, one, two);
+        List<String> optionalFields = type.getOptionalFields();
+        if (optionalFields != null) {
+            double[] opt = DuplicateCheck.compareFieldSet(optionalFields, one, two);
             double totValue = ((DuplicateCheck.REQUIRED_WEIGHT * req[0] * req[1]) + (opt[0] * opt[1])) / ((req[1] * DuplicateCheck.REQUIRED_WEIGHT) + opt[1]);
             return totValue >= DuplicateCheck.duplicateThreshold;
         }
         return req[0] >= DuplicateCheck.duplicateThreshold;
     }
 
-    private static double[] compareFieldSet(String[] fields, BibEntry one, BibEntry two) {
+    private static double[] compareFieldSet(List<String> fields, BibEntry one, BibEntry two) {
         double res = 0;
         double totWeights = 0.;
         for (String field : fields) {

src/test/java/net/sf/jabref/logic/layout/format/CompositeFormatTest.java

@@ -8,28 +8,30 @@
 public class CompositeFormatTest {
 
     @Test
-    public void testComposite() {
-
-        {
-            LayoutFormatter f = new CompositeFormat();
-            Assert.assertEquals("No Change", f.format("No Change"));
-        }
-        {
-            LayoutFormatter f = new CompositeFormat(new LayoutFormatter[] {
-                    fieldText -> fieldText + fieldText,
-                    fieldText -> "A" + fieldText,
-                    fieldText -> "B" + fieldText});
-
-            Assert.assertEquals("BAff", f.format("f"));
-        }
-
-        LayoutFormatter f = new CompositeFormat(new AuthorOrgSci(),
-                new NoSpaceBetweenAbbreviations());
+    public void testEmptyComposite() {
+        LayoutFormatter f = new CompositeFormat();
+        Assert.assertEquals("No Change", f.format("No Change"));
+    }
+
+    @Test
+    public void testArrayComposite() {
+        LayoutFormatter f = new CompositeFormat(new LayoutFormatter[] {fieldText -> fieldText + fieldText,
+                fieldText -> "A" + fieldText, fieldText -> "B" + fieldText});
+
+        Assert.assertEquals("BAff", f.format("f"));
+    }
+
+    @Test
+    public void testDoubleComposite() {
+
+        LayoutFormatter f = new CompositeFormat(new AuthorOrgSci(), new NoSpaceBetweenAbbreviations());
         LayoutFormatter first = new AuthorOrgSci();
         LayoutFormatter second = new NoSpaceBetweenAbbreviations();
 
-        Assert.assertEquals(second.format(first.format("John Flynn and Sabine Gartska")), f.format("John Flynn and Sabine Gartska"));
-        Assert.assertEquals(second.format(first.format("Sa Makridakis and Sa Ca Wheelwright and Va Ea McGee")), f.format("Sa Makridakis and Sa Ca Wheelwright and Va Ea McGee"));
+        Assert.assertEquals(second.format(first.format("John Flynn and Sabine Gartska")),
+                f.format("John Flynn and Sabine Gartska"));
+        Assert.assertEquals(second.format(first.format("Sa Makridakis and Sa Ca Wheelwright and Va Ea McGee")),
+                f.format("Sa Makridakis and Sa Ca Wheelwright and Va Ea McGee"));
     }
 
 }