Minor internal clean ups. Add and use constants.

src/main/java/org/apache/commons/lang3/CharRange.java

@@ -49,6 +49,9 @@ final class CharRange implements Iterable<Character>, Serializable {
     /** Cached toString. */
     private transient String iToString;
 
+    /** Empty array. */
+    static final CharRange[] EMPTY_ARRAY = new CharRange[0];
+
     /**
      * <p>Constructs a {@code CharRange} over a set of characters,
      * optionally negating the range.</p>

src/main/java/org/apache/commons/lang3/CharSet.java

@@ -224,7 +224,7 @@ public class CharSet implements Serializable {
 // NOTE: This is no longer public as CharRange is no longer a public class.
 //       It may be replaced when CharSet moves to Range.
     /*public*/ CharRange[] getCharRanges() {
-        return set.toArray(new CharRange[0]);
+        return set.toArray(CharRange.EMPTY_ARRAY);
     }
 
     //-----------------------------------------------------------------------

src/main/java/org/apache/commons/lang3/time/DurationFormatUtils.java

@@ -479,13 +479,13 @@ public class DurationFormatUtils {
         return padWithZeros ? StringUtils.leftPad(longString, count, '0') : longString;
     }
 
-    static final Object y = "y";
+    static final String y = "y";
-    static final Object M = "M";
+    static final String M = "M";
-    static final Object d = "d";
+    static final String d = "d";
-    static final Object H = "H";
+    static final String H = "H";
-    static final Object m = "m";
+    static final String m = "m";
-    static final Object s = "s";
+    static final String s = "s";
-    static final Object S = "S";
+    static final String S = "S";
 
     /**
      * Parses a classic date format string into Tokens
@@ -507,7 +507,7 @@ public class DurationFormatUtils {
                 buffer.append(ch); // buffer can't be null if inLiteral is true
                 continue;
             }
-            Object value = null;
+            String value = null;
             switch (ch) {
             // TODO: Need to handle escaping of '
             case '\'':
@@ -563,15 +563,17 @@ public class DurationFormatUtils {
         if (inLiteral) { // i.e. we have not found the end of the literal
             throw new IllegalArgumentException("Unmatched quote in format: " + format);
         }
-        return list.toArray(new Token[0]);
+        return list.toArray(Token.EMPTY_ARRAY);
     }
 
-    //-----------------------------------------------------------------------
     /**
      * Element that is parsed from the format pattern.
      */
     static class Token {
 
+        /** Empty array. */
+        private static final Token[] EMPTY_ARRAY = new Token[0];
+
         /**
          * Helper method to determine if a set of tokens contain a value
          *

src/main/java/org/apache/commons/lang3/time/FastDatePrinter.java

@@ -91,6 +91,9 @@ public class FastDatePrinter implements DatePrinter, Serializable {
     // taking the value and adding (mathematically) the ASCII value for '0'.
     // So, don't change this code! It works and is very fast.
 
+    /** Empty array. */
+    private static final Rule[] EMPTY_RULE_ARRAY = new Rule[0];
+
     /**
      * Required for serialization support.
      *
@@ -161,7 +164,7 @@ public class FastDatePrinter implements DatePrinter, Serializable {
      */
     private void init() {
         final List<Rule> rulesList = parsePattern();
-        mRules = rulesList.toArray(new Rule[0]);
+        mRules = rulesList.toArray(EMPTY_RULE_ARRAY);
 
         int len = 0;
         for (int i=mRules.length; --i >= 0; ) {