src/java.base/share/classes/sun/security/x509/X509CertImpl.java

@@ -1974,28 +1974,12 @@
              X509Certificate cert) {
          try {
              byte[] encCertInfo = cert.getEncoded();
              MessageDigest md = MessageDigest.getInstance(algorithm);
              byte[] digest = md.digest(encCertInfo);
-             StringBuilder sb = new StringBuilder(digest.length * 2);
-             for (int i = 0; i < digest.length; i++) {
-                 byte2hex(digest[i], sb);
-             }
-             return sb.toString();
+             return Hex.encoder().encode(digest);
          } catch (NoSuchAlgorithmException | CertificateEncodingException e) {
              // ignored
          }
          return "";
      }
- 
-     /**
-      * Converts a byte to hex digit and writes to the supplied builder
-      */
-     private static void byte2hex(byte b, StringBuilder buf) {
-         char[] hexChars = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
-                 '9', 'A', 'B', 'C', 'D', 'E', 'F' };
-         int high = ((b & 0xf0) >> 4);
-         int low = (b & 0x0f);
-         buf.append(hexChars[high])
-             .append(hexChars[low]);
-     }
  }