Address further error-prone warnings.

Mostly:
 * make final where possible
 * avoid implicit use of platform default charset (also fixes #470).

The charset for skeletons and graphviz dot files is UTF-8 (docs updated), for
spec input/output files, Options.enconding.

docs/md/ant-task.md

@@ -41,29 +41,29 @@ The following attributes are available for invoking the JFlex task.
     be written to `{destdir}/`**`{packagename}`**. This behaviour is similar
     to `javac -d dir.
 
--  `outdir="dir"`\   
+-  `outdir="dir"`\
     The directory to write the generated files to. If not set, the files are
     written to the directory containing the grammar file. This options works
     exactly like JFlex's `-d` command line option, it causes the output file
     to be written to `dir` regardless of the package name.
 
 -  `verbose` (default `"off"`)\
-    Display generation process messages.                     
+    Display generation process messages.
 
 -  `encoding` (if unset uses the JVM default encoding)\
     The character encoding to use when reading lexer specifications and writing java files.
 
--  `dump` (default `"off"`)\           
-    Dump character classes, NFA and DFA tables.                           
+-  `dump` (default `"off"`)\
+    Dump character classes, NFA and DFA tables.
 
 -  `time` or `timeStatistics` (default `"off"`)\
     Display generation time statistics.
 
 -  `nomin` or `skipMinimization` (default `"off"`)\
-    Skip DFA minimisation step.                  
+    Skip DFA minimisation step.
 
 -  `skel="file"` or `skeleton="file"`\
-    Use external skeleton file.                        
+    Use external skeleton file in UTF-8 encoding.
 
 -  `dot` or `generateDot` (default `"off"`)\
     Write graphviz `.dot` files for the generated automata.

docs/md/installing.md

@@ -8,35 +8,35 @@ Installing JFlex
 
 To install JFlex on Windows, follow these three steps:
 
-1.  Unzip the file you downloaded into the directory you want JFlex in. 
+1.  Unzip the file you downloaded into the directory you want JFlex in.
     If you unzipped it to say `C:\`, the following directory structure
     should be generated:
-    
+
 ```
-    C:\jflex-$VERSION\ 
-        +--bin\                        (start scripts) 
-        +--doc\                        (FAQ and manual) 
-        +--examples\ 
-            +--byaccj\                 (calculator example for BYacc/J) 
-            +--cup-maven\              (calculator example for cup and maven) 
-            +--interpreter\            (interpreter example for cup) 
-            +--java\                   (Java lexer specification) 
+    C:\jflex-$VERSION\
+        +--bin\                        (start scripts)
+        +--doc\                        (FAQ and manual)
+        +--examples\
+            +--byaccj\                 (calculator example for BYacc/J)
+            +--cup-maven\              (calculator example for cup and maven)
+            +--interpreter\            (interpreter example for cup)
+            +--java\                   (Java lexer specification)
             +--simple\                 (example scanner with no parser)
-            +--standalone-maven\       (a simple standalone scanner, 
-                                        built with maven) 
-            +--zero-reader\            (Readers that return 0 characters) 
-        +--lib\                        (precompiled classes) 
-        +--src\ 
-            +--main\ 
-                +--config\             (PMD source analyzer configuration) 
-                +--cup\                (JFlex parser spec) 
-                +--java\ 
-                    +--jflex\          (source code of JFlex) 
-                        +--anttask\    (source code of JFlex Ant Task) 
-                        +--gui\        (source code of JFlex UI classes) 
-                        +--unicode\    (source code for Unicode properties) 
-                +--jflex\              (JFlex scanner spec) 
-                +--resources\          (messages and default skeleton file) 
+            +--standalone-maven\       (a simple standalone scanner,
+                                        built with maven)
+            +--zero-reader\            (Readers that return 0 characters)
+        +--lib\                        (precompiled classes)
+        +--src\
+            +--main\
+                +--config\             (PMD source analyzer configuration)
+                +--cup\                (JFlex parser spec)
+                +--java\
+                    +--jflex\          (source code of JFlex)
+                        +--anttask\    (source code of JFlex Ant Task)
+                        +--gui\        (source code of JFlex UI classes)
+                        +--unicode\    (source code for Unicode properties)
+                +--jflex\              (JFlex scanner spec)
+                +--resources\          (messages and default skeleton file)
             +--test\                   (unit tests)
 ```
 
@@ -118,11 +118,11 @@ uses the character encoding `<name>` (e.g. `utf-8`) to read lexer
 specifications and write java files.
 
 `--skel <file>`\
-uses external skeleton `<file>`. This is mainly for JFlex maintenance
-and special low level customisations. Use only when you know what you
-are doing! JFlex comes with a skeleton file in the `src` directory that
-reflects exactly the internal, pre-compiled skeleton and can be used
-with the `-skel` option.
+uses external skeleton `<file>` in UTF-8 encoding. This is mainly for JFlex
+maintenance and special low level customisations. Use only when you know what
+you are doing! JFlex comes with a skeleton file in the `src` directory that
+reflects exactly the internal, pre-compiled skeleton and can be used with the
+`-skel` option.
 
 `--nomin`\
 skip the DFA minimisation step during scanner generation.

jflex/src/main/java/jflex/anttask/JFlexTask.java

@@ -11,9 +11,11 @@
 package jflex.anttask;
 
 import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
 import java.io.LineNumberReader;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import jflex.core.OptionUtils;
@@ -93,8 +95,8 @@ public void findPackageAndClass() throws IOException {
     // find name of the package and class in jflex source file
     packageName = null;
     className = null;
-
-    try (LineNumberReader reader = new LineNumberReader(new FileReader(inputFile))) {
+    Reader r = Files.newBufferedReader(inputFile.toPath(), StandardCharsets.UTF_8);
+    try (LineNumberReader reader = new LineNumberReader(r)) {
       while (className == null || packageName == null) {
         String line = reader.readLine();
         if (line == null) {

jflex/src/main/java/jflex/core/AbstractLexScan.java

@@ -1,7 +1,7 @@
 package jflex.core;
 
 import java.io.File;
-import java.io.FileNotFoundException;
+import java.io.IOException;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
@@ -194,7 +194,7 @@ void includeFile(String filePath) {
       files.push(file);
       file = f;
       Out.println("Including \"" + file + "\"");
-    } catch (FileNotFoundException e) {
+    } catch (IOException e) {
       throw new ScannerException(file, ErrorMessages.NOT_READABLE, lexLine());
     }
   }
@@ -387,5 +387,5 @@ public boolean isColumnCount() {
   protected abstract String lexText();
 
   @SuppressWarnings("WeakerAccess") // Implemented by generated LexScan
-  protected abstract void lexPushStream(File f) throws FileNotFoundException;
+  protected abstract void lexPushStream(File f) throws IOException;
 }

jflex/src/main/java/jflex/core/unicode/CharClasses.java

@@ -28,7 +28,7 @@ public class CharClasses {
   /** debug flag (for char classes only) */
   private static final boolean DEBUG = false;
 
-  private Comparator<IntCharSet> INT_CHAR_SET_COMPARATOR = new IntCharSetComparator();
+  private static final Comparator<IntCharSet> INT_CHAR_SET_COMPARATOR = new IntCharSetComparator();
 
   /** the largest character that can be used in char classes */
   public static final int maxChar = 0x10FFFF;

jflex/src/main/java/jflex/core/unicode/IntCharSet.java

@@ -34,7 +34,7 @@ public final class IntCharSet implements Iterable<Integer> {
   private static final boolean DEBUG = false;
 
   /* invariant: all intervals are disjoint, ordered */
-  private List<Interval> intervals = new ArrayList<>();
+  private final List<Interval> intervals = new ArrayList<>();
 
   /** Creates a charset that contains only one interval. */
   public static IntCharSet of(Interval interval) {
@@ -167,50 +167,48 @@ public void add(Interval interval) {
     for (int i = 0; i < size; i++) {
       Interval elem = intervals.get(i);
 
-      if (elem.end + 1 < interval.start) {
-        continue;
-      }
-
-      if (elem.contains(interval)) {
-        if (DEBUG) assert invariants();
-        return;
-      }
-
-      if (elem.start > interval.end + 1) {
-        intervals.add(i, Interval.copyOf(interval));
-        if (DEBUG) assert invariants();
-        return;
-      }
-
-      if (interval.start < elem.start) {
-        elem.start = interval.start;
-      }
+      if (elem.end + 1 >= interval.start) {
+        if (elem.contains(interval)) {
+          if (DEBUG) assert invariants();
+          return;
+        }
 
-      if (interval.end <= elem.end) {
-        if (DEBUG) assert invariants();
-        return;
-      }
+        if (elem.start > interval.end + 1) {
+          intervals.add(i, Interval.copyOf(interval));
+          if (DEBUG) assert invariants();
+          return;
+        }
 
-      elem.end = interval.end;
+        if (interval.start < elem.start) {
+          elem.start = interval.start;
+        }
 
-      i++;
-      // delete all x with x.contains( interval.end )
-      while (i < size) {
-        Interval x = intervals.get(i);
-        if (x.start > elem.end + 1) {
+        if (interval.end <= elem.end) {
           if (DEBUG) assert invariants();
           return;
         }
 
-        if (x.end > elem.end) {
-          elem.end = x.end;
+        elem.end = interval.end;
+
+        i++;
+        // delete all x with x.contains( interval.end )
+        while (i < size) {
+          Interval x = intervals.get(i);
+          if (x.start > elem.end + 1) {
+            if (DEBUG) assert invariants();
+            return;
+          }
+
+          if (x.end > elem.end) {
+            elem.end = x.end;
+          }
+          intervals.remove(i);
+          size--;
         }
-        intervals.remove(i);
-        size--;
-      }
 
-      if (DEBUG) assert invariants();
-      return;
+        if (DEBUG) assert invariants();
+        return;
+      }
     }
 
     intervals.add(Interval.copyOf(interval));
@@ -611,7 +609,7 @@ Interval getFirstInterval() {
   /** Iterator for enumerating the elements of this IntCharSet */
   public class IntCharSetIterator implements PrimitiveIterator.OfInt {
     /** Iterator over the Interval list */
-    private Iterator<Interval> intervalsIterator;
+    private final Iterator<Interval> intervalsIterator;
     /** Iterator within the current Interval */
     private IntervalIterator current;
 

jflex/src/main/java/jflex/core/unicode/UnicodeProperties.java

@@ -29,7 +29,7 @@ public class UnicodeProperties {
   private static final Pattern WORD_SEP_PATTERN = Pattern.compile("[-_\\s()]");
 
   private int maximumCodePoint;
-  private Map<String, IntCharSet> propertyValueIntervals = new HashMap<>();
+  private final Map<String, IntCharSet> propertyValueIntervals = new HashMap<>();
   private String caselessMatchPartitions;
   private int caselessMatchPartitionSize;
   private IntCharSet caselessMatches[];

jflex/src/main/java/jflex/dfa/DFA.java

@@ -10,9 +10,11 @@
 package jflex.dfa;
 
 import java.io.File;
-import java.io.FileWriter;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
@@ -252,7 +254,9 @@ private static boolean tableEquals(int[][] a, int[][] b) {
    */
   public void writeDot(File file) {
     try {
-      PrintWriter writer = new PrintWriter(new FileWriter(file));
+      PrintWriter writer =
+          new PrintWriter(
+              new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_8));
       writer.println(dotFormat());
       writer.close();
     } catch (IOException e) {

jflex/src/main/java/jflex/exceptions/SilentExit.java

@@ -18,7 +18,7 @@
 public class SilentExit extends Exception {
 
   /** Program exit code if this exception is taken */
-  private int exitCode;
+  private final int exitCode;
 
   /**
    * SilentExit with specified program exit code.

jflex/src/main/java/jflex/logging/Out.java

@@ -12,9 +12,9 @@
 import java.awt.TextArea;
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.file.Files;
 import jflex.base.Build;
 import jflex.exceptions.GeneratorException;
 import jflex.l10n.ErrorMessages;
@@ -385,7 +385,7 @@ public static void showPosition(File file, int line) {
    * @throws IOException if any error occurs
    */
   private static String getLine(File file, int line) throws IOException {
-    BufferedReader reader = new BufferedReader(new FileReader(file));
+    BufferedReader reader = Files.newBufferedReader(file.toPath(), Options.encoding);
 
     String msg = "";
 

jflex/src/main/java/jflex/skeleton/Skeleton.java

@@ -41,7 +41,7 @@
 public class Skeleton {
 
   /** location of default skeleton */
-  private static final String DEFAULT_LOC = "jflex/skeleton.default"; // $NON-NLS-1$
+  private static final String DEFAULT_LOC = "jflex/skeleton.default";
 
   /** expected number of sections in the skeleton file */
   private static final int size = 21;
@@ -59,7 +59,7 @@ public class Skeleton {
   private int pos;
 
   /** The writer to write the skeleton-parts to */
-  private PrintWriter out;
+  private final PrintWriter out;
 
   /**
    * Creates a new skeleton (iterator) instance.
@@ -82,7 +82,7 @@ public void emitNext() {
    */
   public static void makePrivate() {
     for (int i = 0; i < line.length; i++) {
-      line[i] = replace(" public ", " private ", line[i]); // $NON-NLS-1$ //$NON-NLS-2$
+      line[i] = replace(" public ", " private ", line[i]);
     }
   }
 
@@ -92,8 +92,7 @@ public static void makePrivate() {
    * @param skeletonFile the file to read (must be != null and readable)
    */
   public static void readSkelFile(File skeletonFile) {
-    if (skeletonFile == null)
-      throw new IllegalArgumentException("Skeleton file must not be null"); // $NON-NLS-1$
+    if (skeletonFile == null) throw new IllegalArgumentException("Skeleton file must not be null");
 
     if (!skeletonFile.isFile() || !skeletonFile.canRead()) {
       Out.error(ErrorMessages.CANNOT_READ_SKEL, skeletonFile.toString());
@@ -189,7 +188,8 @@ public static void readDefault() {
       throw new GeneratorException();
     }
 
-    try (BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()))) {
+    try (BufferedReader reader =
+        new BufferedReader(new InputStreamReader(url.openStream(), UTF_8))) {
       readSkel(reader);
     } catch (IOException e) {
       Out.error(ErrorMessages.SKEL_IO_ERROR_DEFAULT);