Centralise conversion to hex digit

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1788792 13f79535-47bb-0310-9956-ffa450edef68

Author: sebbASF

src/main/java/org/apache/commons/codec/net/QuotedPrintableCodec.java

@@ -181,8 +181,8 @@ public QuotedPrintableCodec(final String charsetName)
      */
     private static final int encodeQuotedPrintable(final int b, final ByteArrayOutputStream buffer) {
         buffer.write(ESCAPE_CHAR);
-        final char hex1 = Character.toUpperCase(Character.forDigit((b >> 4) & 0xF, 16));
-        final char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, 16));
+        final char hex1 = Utils.hexDigit(b >> 4);
+        final char hex2 = Utils.hexDigit(b);
         buffer.write(hex1);
         buffer.write(hex2);
         return 3;

src/main/java/org/apache/commons/codec/net/URLCodec.java

@@ -47,11 +47,6 @@
  */
 public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, StringDecoder {
 
-    /**
-     * Radix used in encoding and decoding.
-     */
-    static final int RADIX = 16;
-
     /**
      * The default charset used for string decoding and encoding.
      *
@@ -147,8 +142,8 @@ public static final byte[] encodeUrl(BitSet urlsafe, final byte[] bytes) {
                 buffer.write(b);
             } else {
                 buffer.write(ESCAPE_CHAR);
-                final char hex1 = Character.toUpperCase(Character.forDigit((b >> 4) & 0xF, RADIX));
-                final char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, RADIX));
+                final char hex1 = Utils.hexDigit(b >> 4);
+                final char hex2 = Utils.hexDigit(b);
                 buffer.write(hex1);
                 buffer.write(hex2);
             }

src/main/java/org/apache/commons/codec/net/Utils.java

@@ -29,6 +29,11 @@
  */
 class Utils {
 
+    /**
+     * Radix used in encoding and decoding.
+     */
+    private static final int RADIX = 16;
+
     /**
      * Returns the numeric value of the character <code>b</code> in radix 16.
      *
@@ -40,11 +45,21 @@ class Utils {
      *             Thrown when the byte is not valid per {@link Character#digit(char,int)}
      */
     static int digit16(final byte b) throws DecoderException {
-        final int i = Character.digit((char) b, URLCodec.RADIX);
+        final int i = Character.digit((char) b, RADIX);
         if (i == -1) {
-            throw new DecoderException("Invalid URL encoding: not a valid digit (radix " + URLCodec.RADIX + "): " + b);
+            throw new DecoderException("Invalid URL encoding: not a valid digit (radix " + RADIX + "): " + b);
         }
         return i;
     }
 
+    /**
+     * Returns the upper case hex digit of the lower 4 bits of the int.
+     *
+     * @param b the input int
+     * @return the upper case hex digit of the lower 4 bits of the int.
+     */
+    static char hexDigit(int b) {
+        return Character.toUpperCase(Character.forDigit(b & 0xF, RADIX));
+    }
+
 }