8251989: Hex formatting and parsing utility

Reviewed-by: tvaleev, chegar, naoto, darcy

Author: Roger Riggs

src/java.base/share/classes/java/lang/Integer.java

@@ -264,10 +264,18 @@ public static String toUnsignedString(int i, int radix) {
      * <blockquote>
      *  {@code Integer.toHexString(n).toUpperCase()}
      * </blockquote>
+     * <p>
+     * @apiNote
+     * The {@link java.util.HexFormat} class provides formatting and parsing
+     * of byte arrays and primitives to return a string or adding to an {@link Appendable}.
+     * {@code HexFormat} formats and parses uppercase or lowercase hexadecimal characters,
+     * with leading zeros and for byte arrays includes for each byte
+     * a delimiter, prefix, and suffix.
      *
      * @param   i   an integer to be converted to a string.
      * @return  the string representation of the unsigned integer value
      *          represented by the argument in hexadecimal (base&nbsp;16).
+     * @see java.util.HexFormat
      * @see #parseUnsignedInt(String, int)
      * @see #toUnsignedString(int, int)
      * @since   1.0.2

src/java.base/share/classes/java/lang/Long.java

@@ -299,11 +299,19 @@ private static BigInteger toUnsignedBigInteger(long i) {
      * <blockquote>
      *  {@code Long.toHexString(n).toUpperCase()}
      * </blockquote>
+     * <p>
+     * @apiNote
+     * The {@link java.util.HexFormat} class provides formatting and parsing
+     * of byte arrays and primitives to return a string or adding to an {@link Appendable}.
+     * {@code HexFormat} formats and parses uppercase or lowercase hexadecimal characters,
+     * with leading zeros and for byte arrays includes for each byte
+     * a delimiter, prefix, and suffix.
      *
      * @param   i   a {@code long} to be converted to a string.
      * @return  the string representation of the unsigned {@code long}
      *          value represented by the argument in hexadecimal
      *          (base&nbsp;16).
+     * @see java.util.HexFormat
      * @see #parseUnsignedLong(String, int)
      * @see #toUnsignedString(long, int)
      * @since   1.0.2

src/java.base/share/classes/java/lang/module/Resolver.java

@@ -35,6 +35,7 @@
 import java.util.Deque;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.HexFormat;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -475,25 +476,17 @@ private void checkHashes() {
                     if (actualHash == null)
                         findFail("Unable to compute the hash of module %s", dn);
                     if (!Arrays.equals(recordedHash, actualHash)) {
+                        HexFormat hex = HexFormat.of();
                         findFail("Hash of %s (%s) differs to expected hash (%s)" +
-                                 " recorded in %s", dn, toHexString(actualHash),
-                                 toHexString(recordedHash), descriptor.name());
+                                 " recorded in %s", dn, hex.formatHex(actualHash),
+                                hex.formatHex(recordedHash), descriptor.name());
                     }
                 }
             }
 
         }
     }
 
-    private static String toHexString(byte[] ba) {
-        StringBuilder sb = new StringBuilder(ba.length * 2);
-        for (byte b: ba) {
-            sb.append(String.format("%02x", b & 0xff));
-        }
-        return sb.toString();
-    }
-
-
     /**
      * Computes the readability graph for the modules in the given Configuration.
      *