Fix PMD warnings.

src/main/java/edu/hm/hafner/analysis/FileReaderFactory.java

@@ -59,6 +59,7 @@ public FileReaderFactory(final Path file) {
         this(file, null);
     }
 
+    @SuppressWarnings("PMD.CloseResource")
     @Override @MustBeClosed
     public Reader create() {
         try {

src/main/java/edu/hm/hafner/analysis/FullTextFingerprint.java

@@ -97,7 +97,7 @@ private String asHex(final byte[] bytes) {
             hexChars[j * 2] = HEX_CHARACTERS[v >>> 4];
             hexChars[j * 2 + 1] = HEX_CHARACTERS[v & 0x0F];
         }
-        return new String(hexChars);
+        return String.valueOf(hexChars);
     }
 
     @VisibleForTesting

src/main/java/edu/hm/hafner/analysis/Issue.java

@@ -60,7 +60,7 @@ public static String getPropertyValueAsString(final Issue issue, final String pr
      * @return the function that obtains the value
      */
     public static Function<Issue, String> getPropertyValueGetter(final String propertyName) {
-        return issue -> Issue.getPropertyValueAsString(issue, propertyName);
+        return issue -> getPropertyValueAsString(issue, propertyName);
     }
 
     /**

src/main/java/edu/hm/hafner/analysis/IssueDifference.java

@@ -84,19 +84,16 @@ public IssueDifference(final Report currentIssues, final String referenceId,
 
     private void findIssuesInChangedCode(final Map<String, Integer> includes) {
         for (Entry<String, Integer> include : includes.entrySet()) {
-            newIssues.filter(issue -> filter(issue, include.getKey(), include.getValue()))
+            newIssues.filter(issue -> isInFileAtPosition(issue, include.getKey(), include.getValue()))
                     .stream()
                     .map(Issue::getId)
                     .map(newIssues::remove)
                     .forEach(newIssuesInChangedCode::add);
         }
     }
 
-    private boolean filter(final Issue issue, final String fileName, final int line) {
-        if (!issue.getFileName().endsWith(fileName)) {
-            return false;
-        }
-        return issue.affectsLine(line);
+    private boolean isInFileAtPosition(final Issue issue, final String fileName, final int line) {
+        return issue.getFileName().endsWith(fileName) && issue.affectsLine(line);
     }
 
     private List<UUID> matchIssuesByEquals(final Report currentIssues) {

src/main/java/edu/hm/hafner/analysis/IssuesInModifiedCodeMarker.java

@@ -35,9 +35,6 @@ public void markIssuesInModifiedCode(final Report report, final Map<String, Set<
     private boolean affectsChangedLineInFile(final Issue issue, final String fileName, final Set<Integer> lines) {
         var normalizedPath = PATH_UTIL.getRelativePath(fileName);
 
-        if (!issue.getFileName().endsWith(normalizedPath)) { // check only the suffix
-            return false;
-        }
-        return lines.stream().anyMatch(issue::affectsLine);
+        return issue.getFileName().endsWith(normalizedPath) && lines.stream().anyMatch(issue::affectsLine);
     }
 }

src/main/java/edu/hm/hafner/analysis/LookaheadParser.java

@@ -1,7 +1,8 @@
 package edu.hm.hafner.analysis;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.Optional;
-import java.util.Stack;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
@@ -12,9 +13,9 @@
 
 /**
  * Parses a report file line by line for issues using a pre-defined regular expression. If the regular expression
- * matches then the abstract method {@link #createIssue(Matcher, LookaheadStream, IssueBuilder)} will be called. Sub
- * classes need to provide an implementation that transforms the {@link Matcher} instance into a new issue. If required,
- * sub classes may consume additional lines from the report file before control is handed back to the template method of
+ * matches then the abstract method {@link #createIssue(Matcher, LookaheadStream, IssueBuilder)} will be called.
+ * Subclasses need to provide an implementation that transforms the {@link Matcher} instance into a new issue. If required,
+ * subclasses may consume additional lines from the report file before control is handed back to the template method of
  * this parser.
  *
  * @author Ullrich Hafner
@@ -38,7 +39,7 @@ public abstract class LookaheadParser extends IssueParser {
 
     private final Pattern pattern;
 
-    private final Stack<String> recursiveDirectories;
+    private final Deque<String> recursiveDirectories;
 
     /**
      * Creates a new instance of {@link LookaheadParser}.
@@ -50,7 +51,7 @@ protected LookaheadParser(final String pattern) {
         super();
 
         this.pattern = Pattern.compile(pattern);
-        this.recursiveDirectories = new Stack<>();
+        this.recursiveDirectories = new ArrayDeque<>();
     }
 
     @Override
@@ -65,6 +66,7 @@ public Report parse(final ReaderFactory readerFactory) throws ParsingException,
         return postProcess(report);
     }
 
+    @SuppressWarnings("PMD.DoNotUseThreads")
     private void parse(final Report report, final LookaheadStream lookahead) {
         try (IssueBuilder builder = new IssueBuilder()) {
             while (lookahead.hasNext()) {
@@ -107,7 +109,7 @@ protected void preprocessLine(final String line) {
      * @return The new directory to change to
      */
     private String enterDirectory(final String line, final Report log) {
-        extractDirectory(line, ENTERING_DIRECTORY_PATH, log).map(recursiveDirectories::push);
+        extractDirectory(line, ENTERING_DIRECTORY_PATH, log).ifPresent(recursiveDirectories::push);
         return recursiveDirectories.isEmpty() ? NO_DIRECTORY : recursiveDirectories.peek();
     }
 
@@ -118,9 +120,9 @@ private String enterDirectory(final String line, final Report log) {
      * @return The last directory seen, or an empty String if we have returned to the beginning
      */
     private String leaveDirectory() {
-        if (!recursiveDirectories.empty()) {
+        if (!recursiveDirectories.isEmpty()) {
             recursiveDirectories.pop();
-            if (!recursiveDirectories.empty()) {
+            if (!recursiveDirectories.isEmpty()) {
                 return recursiveDirectories.peek();
             }
         }

src/main/java/edu/hm/hafner/analysis/ModuleDetector.java

@@ -108,7 +108,7 @@ public String guessModuleName(final String originalFileName) {
      * @return the found files (as absolute paths)
      */
     private List<String> find(final Path path) {
-        ArrayList<String> absoluteFileNames = new ArrayList<>();
+        List<String> absoluteFileNames = new ArrayList<>();
 
         for (AbstractModuleDetector moduleDetector : moduleDetectors) {
             String[] relativeFileNames = factory.find(path, moduleDetector.getPattern());

src/main/java/edu/hm/hafner/analysis/PackageNameResolver.java

@@ -3,13 +3,14 @@
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
 import edu.hm.hafner.util.VisibleForTesting;
-import static edu.hm.hafner.analysis.PackageDetectors.*;
 
+import static edu.hm.hafner.analysis.PackageDetectors.*;
 import static java.util.function.Function.*;
 
 /**
@@ -29,7 +30,7 @@ public PackageNameResolver() {
 
     @VisibleForTesting
     PackageNameResolver(final FileSystem fileSystem) {
-        ArrayList<AbstractPackageDetector> detectors = new ArrayList<>(Arrays.asList(
+        List<AbstractPackageDetector> detectors = new ArrayList<>(Arrays.asList(
                 new JavaPackageDetector(fileSystem),
                 new CSharpNamespaceDetector(fileSystem),
                 new KotlinPackageDetector(fileSystem)

src/main/java/edu/hm/hafner/analysis/Report.java

@@ -358,10 +358,14 @@ public Report addAll(final Report... reports) {
     }
 
     private boolean contains(final Issue issue) {
-        if (elements.contains(issue)) {
-            return true;
-        }
-        return subReports.stream().map(r -> r.contains(issue)).reduce(Boolean::logicalOr).orElse(false);
+        return elements.contains(issue) || subReportsContains(issue);
+    }
+
+    private Boolean subReportsContains(final Issue issue) {
+        return subReports.stream()
+                .map(r -> r.contains(issue))
+                .reduce(Boolean::logicalOr)
+                .orElse(false);
     }
 
     @VisibleForTesting
@@ -1157,7 +1161,7 @@ private String readLongString(final ObjectInputStream input) throws IOException
         for (int j = 0; j < chars.length; j++) {
             chars[j] = input.readChar();
         }
-        return new String(chars);
+        return String.valueOf(chars);
     }
 
     /**

src/main/java/edu/hm/hafner/analysis/Severity.java

@@ -96,18 +96,18 @@ public static Severity valueOf(@CheckForNull final String severity, final Severi
      */
     public static Severity guessFromString(@CheckForNull final String severity) {
         if (StringUtils.containsAnyIgnoreCase(severity, "error", "severe", "critical", "fatal")) {
-            return Severity.ERROR;
+            return ERROR;
         }
         if (StringUtils.containsAnyIgnoreCase(severity, "info", "note", "low")) {
-            return Severity.WARNING_LOW;
+            return WARNING_LOW;
         }
         if (StringUtils.containsAnyIgnoreCase(severity, "warning", "medium")) {
-            return Severity.WARNING_NORMAL;
+            return WARNING_NORMAL;
         }
         if (StringUtils.containsIgnoreCase(severity, "high")) {
-            return Severity.WARNING_HIGH;
+            return WARNING_HIGH;
         }
-        return Severity.WARNING_LOW;
+        return WARNING_LOW;
     }
 
     /**
@@ -120,7 +120,7 @@ public static Severity guessFromString(@CheckForNull final String severity) {
      */
     public static Collection<Severity> collectSeveritiesFrom(final Severity minimumSeverity) {
         List<Severity> priorities = new ArrayList<>();
-        priorities.add(Severity.ERROR);
+        priorities.add(ERROR);
         if (WARNING_HIGH.equals(minimumSeverity)) {
             priorities.add(WARNING_HIGH);
         }

src/main/java/edu/hm/hafner/analysis/parser/AjcParser.java

@@ -94,7 +94,7 @@ private void fillMessageAndCategory(final IssueBuilder builder, final String lin
             category = Categories.DEPRECATION;
         }
         else if (line.contains("adviceDidNotMatch")) {
-            category = AjcParser.ADVICE;
+            category = ADVICE;
         }
         else {
             category = "";

src/main/java/edu/hm/hafner/analysis/parser/IarCstatParser.java

@@ -19,6 +19,8 @@ public class IarCstatParser extends LookaheadParser {
 
     private static final String IAR_WARNING_PATTERN = ANT_TASK
             + "(?:\"?(.*?)\"?[\\(,](\\d+)\\)?\\s+)?(Severity-(?:Low|Medium|High))\\[(\\S+)\\]:(.*)$";
+    private static final String SEVERITY_LOW = "Severity-Low";
+    private static final String SEVERITY_HIGH = "Severity-High";
 
     /**
      * Creates a new instance of {@link IarCstatParser}.
@@ -45,10 +47,10 @@ protected Optional<Issue> createIssue(final Matcher matcher, final LookaheadStre
 
     private Severity mapSeverity(final String category) {
         Severity severity;
-        if ("Severity-Low".equals(category)) {
+        if (SEVERITY_LOW.equals(category)) {
             severity = Severity.WARNING_LOW;
         }
-        else if ("Severity-High".equals(category)) {
+        else if (SEVERITY_HIGH.equals(category)) {
             severity = Severity.WARNING_HIGH;
         }
         else {

src/main/java/edu/hm/hafner/analysis/parser/IdeaInspectionParser.java

@@ -3,7 +3,6 @@
 import java.util.List;
 import java.util.Optional;
 
-import edu.hm.hafner.analysis.util.IntegerParser;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.text.StringEscapeUtils;
 import org.w3c.dom.Document;
@@ -16,6 +15,7 @@
 import edu.hm.hafner.analysis.ReaderFactory;
 import edu.hm.hafner.analysis.Report;
 import edu.hm.hafner.analysis.Severity;
+import edu.hm.hafner.analysis.util.IntegerParser;
 import edu.hm.hafner.analysis.util.XmlElementUtil;
 
 /**
@@ -26,6 +26,8 @@
 public class IdeaInspectionParser extends IssueParser {
     private static final long serialVersionUID = 3307389086106375473L;
     private static final String PATH_PREFIX = "file://";
+    private static final String WARNING = "WARNING";
+    private static final String ERROR = "ERROR";
 
     @Override
     public Report parse(final ReaderFactory readerFactory) throws ParsingException {
@@ -58,10 +60,10 @@ private Report parseProblems(final List<Element> elements) {
 
     private Severity getPriority(final String severity) {
         Severity priority = Severity.WARNING_LOW;
-        if ("WARNING".equals(severity)) {
+        if (WARNING.equals(severity)) {
             priority = Severity.WARNING_NORMAL;
         }
-        else if ("ERROR".equals(severity)) {
+        else if (ERROR.equals(severity)) {
             priority = Severity.WARNING_HIGH;
         }
         return priority;

src/main/java/edu/hm/hafner/analysis/parser/LintParser.java

@@ -19,6 +19,7 @@
  */
 public class LintParser extends IssueParser {
     private static final long serialVersionUID = 3341424685245834156L;
+    private static final String FILE = "file";
 
     @Override
     public Report parse(final ReaderFactory readerFactory) throws ParsingException {
@@ -56,7 +57,7 @@ public void startElement(final String namespaceURI,
                 return; // Start element, good to skip
             }
 
-            if ("file".equals(key)) {
+            if (FILE.equals(key)) {
                 fileName = atts.getValue("name");
                 return;
             }

src/main/java/edu/hm/hafner/analysis/parser/MsBuildParser.java

@@ -38,6 +38,8 @@ public class MsBuildParser extends LookaheadParser {
 
     private static final Pattern IGNORED_TOOLS_PATTERN = Pattern.compile("(?!.exe)(\\.[^.]+)$");
     private static final Pattern LINKER_CAUSE = Pattern.compile(".*imported by '([A-Za-z0-9\\-_.]+)'.*");
+    private static final String EXPECTED_CATEGORY = "Expected";
+    private static final String MSBUILD = "MSBUILD";
 
     /**
      * Creates a new instance of {@link MsBuildParser}.
@@ -76,7 +78,7 @@ protected Optional<Issue> createIssue(final Matcher matcher, final LookaheadStre
         }
 
         String category = matcher.group(9);
-        if ("Expected".equals(category)) {
+        if (EXPECTED_CATEGORY.equals(category)) {
             return Optional.empty();
         }
         return builder.setLineStart(matcher.group(5))
@@ -124,15 +126,15 @@ else if (StringUtils.isNotBlank(matcher.group(7))) {
         if (canResolveRelativeFileName(fileName, projectDir)) {
             fileName = FilenameUtils.concat(projectDir, fileName);
         }
-        if ("MSBUILD".equals(fileName.trim())) {
+        if (MSBUILD.equals(fileName.trim())) {
             fileName = "-";
         }
         return fileName;
     }
 
     private boolean canResolveRelativeFileName(final String fileName, final String projectDir) {
         return StringUtils.isNotBlank(projectDir) && FilenameUtils.getPrefixLength(fileName) == 0
-                && !"MSBUILD".equals(fileName.trim());
+                && !MSBUILD.equals(fileName.trim());
     }
 }
 

src/main/java/edu/hm/hafner/analysis/parser/RevApiParser.java

@@ -20,6 +20,7 @@
  */
 public class RevApiParser extends JsonIssueParser {
     private static final long serialVersionUID = -2452699725595063377L;
+    private static final int CAPACITY = 1024;
 
     @Override
     protected void parseJsonArray(final Report report, final JSONArray jsonReport, final IssueBuilder issueBuilder) {
@@ -102,7 +103,7 @@ private Severity toSeverity(final String level) {
     }
 
     private String getDescription(final JSONObject jsonIssue) {
-        StringBuilder severityDescription = new StringBuilder();
+        StringBuilder severityDescription = new StringBuilder(CAPACITY);
         for  (Object severity :  jsonIssue.getJSONArray("classification")) {
             if (severity instanceof JSONObject) {
                 severityDescription.append("<p>Compatibility: ")

src/main/java/edu/hm/hafner/analysis/parser/RfLintParser.java

@@ -165,6 +165,7 @@ public Report parse(final ReaderFactory readerFactory) {
         }
     }
 
+    @SuppressWarnings("PMD.DoNotUseThreads")
     private void parseLine(final IssueBuilder builder, final Report warnings, final String line) {
         Matcher fileMatcher = FILE_PATTERN.matcher(line);
         if (fileMatcher.find()) {

src/main/java/edu/hm/hafner/analysis/parser/SbtScalacParser.java

@@ -10,14 +10,16 @@
 import edu.hm.hafner.util.LookaheadStream;
 
 /**
- * A parser for the sbt scala compiler warnings. You should use -feature and -deprecation compiler opts.
+ * A parser for the sbt scala compiler warnings. You should use {@code -feature} and {@code -deprecation} compiler
+ * opts.
  *
  * @author Hochak Hung
  */
 public class SbtScalacParser extends LookaheadParser {
     private static final long serialVersionUID = -4233964844965517977L;
 
     private static final String SBT_WARNING_PATTERN = "^(\\[warn\\]|\\[error\\](?!\\s+Total\\stime:))\\s*(.*?):(\\d+)(?::\\d+)?:\\s*(.*)$";
+    private static final String ERROR = "[error]";
 
     /**
      * Creates a new instance of {@link SbtScalacParser}.
@@ -37,7 +39,7 @@ protected Optional<Issue> createIssue(final Matcher matcher, final LookaheadStre
     }
 
     private Severity mapPriority(final Matcher matcher) {
-        if ("[error]".equals(matcher.group(1))) {
+        if (ERROR.equals(matcher.group(1))) {
             return Severity.WARNING_HIGH;
         }
         else {