Refactoring to reduce sonar code smell fixes

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/Ctags.java

@@ -574,6 +574,7 @@ public int exitValue() {
 
             @Override
             public void destroy() {
+                //Empty Method
             }
         };
 

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/CtagsReader.java

@@ -258,11 +258,9 @@ public void readLine(String tagLine) {
         addTag(defs, cidx.lineno, def, type, match, classInher, signature,
             cidx.lineStart, cidx.lineEnd);
 
-        String[] args;
         if (signature != null && !signature.equals("()") &&
-                !signature.startsWith("() ") && (args =
-                splitSignature(signature)) != null) {
-            for (String arg : args) {
+                !signature.startsWith("() ") ) {
+            for (String arg : splitSignature(signature)) {
                 //TODO this algorithm assumes that data types occur to
                 //     the left of the argument name, so it will not
                 //     work for languages like rust, kotlin, etc. which
@@ -287,7 +285,7 @@ public void readLine(String tagLine) {
                     arg = a[0];  // throws away assigned value
                 }
                 arg = arg.trim();
-                if (arg.length() < 1) {
+                if (arg.isEmpty()) {
                     continue;
                 }
 
@@ -433,7 +431,7 @@ private CpatIndex bestIndexOfTag(int lineno, String whole, String str) {
      * @return a defined instance
      */
     private CpatIndex bestIndexOfArg(int lineno, String whole, String arg) {
-        if (whole.length() < 1) {
+        if (whole.isEmpty()) {
             return new CpatIndex(lineno, 0, 1, true);
         }
 
@@ -551,9 +549,9 @@ private PatResult bestMatch(String whole, String arg, Pattern argpat) {
      * ending with a word character.
      */
     private int strictIndexOf(String whole, String substr) {
-        boolean strictLeft = substr.length() > 0 && WORD_CHAR.matcher(
+        boolean strictLeft = !substr.isEmpty() && WORD_CHAR.matcher(
             String.valueOf(substr.charAt(0))).matches();
-        boolean strictRight = substr.length() > 0 && WORD_CHAR.matcher(
+        boolean strictRight = !substr.isEmpty() && WORD_CHAR.matcher(
             String.valueOf(substr.charAt(substr.length() - 1))).matches();
 
         int spos = 0;
@@ -703,7 +701,7 @@ private static String[] splitSignature(String signature) {
         int soff = off0;
         int eoff = offz;
         if (soff >= eoff) {
-            return null;
+            return new String[0];
         }
 
         // Trim outer punctuation if it exists.

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/Definitions.java

@@ -23,6 +23,7 @@
  */
 package org.opengrok.indexer.analysis;
 
+import org.jetbrains.annotations.Nullable;
 import org.opengrok.indexer.util.WhitelistObjectInputFilter;
 
 import java.io.ByteArrayInputStream;
@@ -33,11 +34,14 @@
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 public class Definitions implements Serializable {
 
@@ -60,14 +64,14 @@ public class Definitions implements Serializable {
     public static class LineTagMap implements Serializable {
 
         private static final long serialVersionUID = 1191703801007779481L;
-        private final Map<String, Set<Tag>> sym_tags; //NOPMD
+        private final Map<String, Set<Tag>> symTags; //NOPMD
 
         protected LineTagMap() {
-            this.sym_tags = new HashMap<>();
+            this.symTags = new HashMap<>();
         }
     }
     // line number -> tag map
-    private final Map<Integer, LineTagMap> line_maps;
+    private final Map<Integer, LineTagMap> lineMaps;
 
     /**
      * Map from symbol to the line numbers on which the symbol is defined.
@@ -80,7 +84,7 @@ protected LineTagMap() {
 
     public Definitions() {
         symbols = new HashMap<>();
-        line_maps = new HashMap<>();
+        lineMaps = new HashMap<>();
         tags = new ArrayList<>();
     }
 
@@ -121,16 +125,18 @@ public boolean hasSymbol(String symbol) {
      * @return {@code true} if {@code symbol} is defined on the specified line
      */
     public boolean hasDefinitionAt(String symbol, int lineNumber, String[] strs) {
-        Set<Integer> lines = symbols.get(symbol);
         if (strs.length > 0) {
             strs[0] = "none";
         }
 
         // Get tag info
-        if (lines != null && lines.contains(lineNumber)) {
-            LineTagMap lineMap = line_maps.get(lineNumber);
+        boolean isDefinitionPresent = Optional.ofNullable(symbols.get(symbol))
+                .filter(lines -> lines.contains(lineNumber))
+                .isPresent();
+        if (isDefinitionPresent) {
+            LineTagMap lineMap = lineMaps.get(lineNumber);
             if (lineMap != null) {
-                for (Tag tag : lineMap.sym_tags.get(symbol)) {
+                for (Tag tag : lineMap.symTags.get(symbol)) {
                     if (tag.used) {
                         continue;
                     }
@@ -180,20 +186,15 @@ public List<Tag> getTags() {
      * Get a list of all tags on given line.
      *
      * @param line line number
-     * @return list of tags
+     * @return list of tags or null
      */
-    public List<Tag> getTags(int line) {
-        LineTagMap lineMap = line_maps.get(line);
-        List<Tag> result = null;
-
-        if (lineMap != null) {
-            result = new ArrayList<>();
-            for (Set<Tag> ltags : lineMap.sym_tags.values()) {
-                result.addAll(ltags);
-            }
-        }
-
-        return result;
+    public @Nullable List<Tag> getTags(int line) {
+        return Optional.ofNullable(lineMaps.get(line))
+                .map(lineMap -> lineMap.symTags.values().stream()
+                        .flatMap(Collection::stream)
+                        .collect(Collectors.toList())
+                )
+                .orElse(null);
     }
 
     /**
@@ -267,26 +268,20 @@ public void addTag(int line, String symbol, String type, String text,
         Tag newTag = new Tag(line, symbol, type, text, namespace, signature,
             lineStart, lineEnd);
         tags.add(newTag);
-        Set<Integer> lines = symbols.get(symbol);
-        if (lines == null) {
-            lines = new HashSet<>();
-            symbols.put(symbol, lines);
-        }
+        Set<Integer> lines = symbols.computeIfAbsent(symbol,
+                k -> new HashSet<>());
         Integer aLine = line;
         lines.add(aLine);
 
         // Get per line map
-        LineTagMap lineMap = line_maps.get(aLine);
-        if (lineMap == null) {
-            lineMap = new LineTagMap();
-            line_maps.put(aLine, lineMap);
-        }
+        LineTagMap lineMap = lineMaps.computeIfAbsent(aLine,
+                key -> new LineTagMap());
 
         // Insert sym->tag map for this line
-        Set<Tag> ltags = lineMap.sym_tags.get(symbol);
+        Set<Tag> ltags = lineMap.symTags.get(symbol);
         if (ltags == null) {
             ltags = new HashSet<>();
-            lineMap.sym_tags.put(symbol, ltags);
+            lineMap.symTags.put(symbol, ltags);
         }
         ltags.add(newTag);
     }

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/JFlexXrefUtils.java

@@ -26,11 +26,12 @@
 
 import java.io.IOException;
 import java.io.Writer;
+import java.util.Collection;
 import java.util.Comparator;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
@@ -55,6 +56,7 @@ public class JFlexXrefUtils {
      * Matches an HTML 5 ID or Name.
      */
     private static final Pattern HTML5_ID_NAME = Pattern.compile("(?U)^\\S+$");
+    private static final String A_HREF_START = "<a href=\"";
 
     /**
      * Appends the {@code url} to the specified {@code out} {@link Writer}.
@@ -89,7 +91,7 @@ public static void appendLink(Writer out, JFlexLexer lexer, String url,
         }
 
         url = result.getUri();
-        out.write("<a href=\"");
+        out.write(A_HREF_START);
         Util.htmlize(url, out);
         out.write("\">");
         Util.htmlize(url, out);
@@ -166,16 +168,13 @@ public static Scope maybeNewScope(boolean scopesEnabled,
         Scope existingScope, JFlexStackingLexer lexer, Definitions defs) {
         if (scopesEnabled && existingScope == null) {
             int line = lexer.getLineNumber();
-            if (defs != null) {
-                List<Tag> tags = defs.getTags(line);
-                if (tags != null) {
-                    for (Tag tag : tags) {
-                        if (tag.type.startsWith("function") || tag.type.startsWith("method")) {
-                            return new Scope(tag.line, tag.line, tag.symbol, tag.namespace, tag.signature);
-                        }
-                    }
-                }
-            }
+            return Optional.ofNullable(defs)
+                    .map(objDefs -> objDefs.getTags(line))
+                    .stream().flatMap(Collection::stream)
+                    .filter(tag -> tag.type.startsWith("function") || tag.type.startsWith("method"))
+                    .findFirst()
+                    .map(tag -> new Scope(tag.line, tag.line, tag.symbol, tag.namespace, tag.signature))
+                    .orElse(null);
         }
         return null;
     }
@@ -234,11 +233,11 @@ public static boolean writeSymbol(Writer out, Definitions defs,
         if (defs != null && defs.hasDefinitionAt(symbol, line, strs)) {
             // This is the definition of the symbol.
             String type = strs[0];
-            String style_class = "d";
+            String styleClass = "d";
 
             XrefStyle style = XrefStyle.getStyle(type);
             if (style != null) {
-                style_class = style.ssClass;
+                styleClass = style.ssClass;
             }
 
             // 1) Create an anchor for direct links. (Perhaps we should only
@@ -255,20 +254,20 @@ public static boolean writeSymbol(Writer out, Definitions defs,
             //    explained by @tulinkry.
             if (HTML5_ID_NAME.matcher(symbol).matches()) {
                 out.append("<a class=\"");
-                out.append(style_class);
+                out.append(styleClass);
                 out.append("\" name=\"");
                 Util.htmlize(symbol, out);
                 out.append("\"/>");
             }
 
             // 2) Create a link that searches for all references to this symbol.
-            out.append("<a href=\"");
+            out.append(A_HREF_START);
             out.append(urlPrefix);
             out.append(QueryParameters.REFS_SEARCH_PARAM_EQ);
             Util.qurlencode(symbol, out);
             appendProject(out, project);
             out.append("\" class=\"");
-            out.append(style_class);
+            out.append(styleClass);
             out.append(" intelliWindow-symbol\"");
             out.append(" data-definition-place=\"def\"");
             out.append(">");
@@ -281,7 +280,7 @@ public static boolean writeSymbol(Writer out, Definitions defs,
             // that is defined more than once in this file. In either case, we
             // can't generate a direct link to the definition, so generate a
             // link to search for all definitions of that symbol instead.
-            out.append("<a href=\"");
+            out.append(A_HREF_START);
             out.append(urlPrefix);
             out.append(QueryParameters.DEFS_SEARCH_PARAM_EQ);
             Util.qurlencode(symbol, out);
@@ -307,11 +306,11 @@ public static boolean writeSymbol(Writer out, Definitions defs,
     public static void writeSameFileLinkSymbol(Writer out, String symbol)
             throws IOException {
         // This is a reference to a symbol defined exactly once in this file.
-        String style_class = "d";
+        String styleClass = "d";
 
         // Generate a direct link to the symbol definition.
         out.append("<a class=\"");
-        out.append(style_class);
+        out.append(styleClass);
         out.append(" intelliWindow-symbol\" href=\"#");
         Util.uriEncode(symbol, out);
         out.append("\"");

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/hcl/HCLLexer.java

@@ -49,7 +49,7 @@ public abstract class HCLLexer extends JFlexSymbolMatcher
 
     private Stack<HCLLexerData> data;
 
-    public HCLLexer() {
+    protected HCLLexer() {
         dataHead = new HCLLexerData();
     }
 
@@ -113,7 +113,7 @@ public void hereOp(String capture) throws IOException {
      * @return true if a Here state was pushed
      */
     public boolean maybeHereStart() throws IOException {
-        if (dataHead.hereSettings != null && dataHead.hereSettings.size() > 0) {
+        if (dataHead.hereSettings != null && !dataHead.hereSettings.isEmpty()) {
             HereDocSettings settings = dataHead.hereSettings.peek();
             yypush(settings.state);
             disjointSpan(HtmlConsts.STRING_CLASS);
@@ -141,7 +141,7 @@ public boolean maybeHereEnd(String capture) throws IOException {
 
         offer(capture);
 
-        if (dataHead.hereSettings.size() > 0) {
+        if (!dataHead.hereSettings.isEmpty()) {
             settings = dataHead.hereSettings.peek();
             yybegin(settings.state);
             if (didZspan) {

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/yaml/YamlAnalyzerFactory.java

@@ -35,11 +35,8 @@ public class YamlAnalyzerFactory extends FileAnalyzerFactory {
         "YML"
     };
 
-    public static final YamlAnalyzerFactory DEFAULT_INSTANCE =
-            new YamlAnalyzerFactory();
 
-
-    private YamlAnalyzerFactory() {
+    public YamlAnalyzerFactory() {
         super(null, null, SUFFIXES, null, null, "text/plain",
                 AbstractAnalyzer.Genre.PLAIN, NAME);
     }