Simplifies code.

modules/util/RandomUtil.js

  */
 var ALPHANUM = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
 
+/**
+ * Hexadecimal digits.
+ * @const
+ */
+var HEX_DIGITS = '0123456789abcdef';
+
 /**
  * Generates random int within the range [min, max]
  * @param min the minimum value for the generated number
     return result;
 }
 
-/**
- * Generates random hex number within the range [min, max]
- * @param min the minimum value for the generated number
- * @param max the maximum value for the generated number
- * @returns random hex number
- */
-function rangeRandomHex(min, max)
-{
-    return randomInt(min, max).toString(16);
-}
-
 /**
  * Exported interface.
  */
 var RandomUtil = {
     /**
-     * Generates hex number with length 4
-     */
-    random4digitsHex: function () {
-        return rangeRandomHex(0x1000, 0xFFFF);
-    },
-    /**
-     * Generates hex number with length 8
+     * Returns a random hex digit.
+     * @returns {*}
      */
-    random8digitsHex: function () {
-        return rangeRandomHex(0x10000000, 0xFFFFFFFF);
+    randomHexDigit: function() {
+        return randomElement(HEX_DIGITS);
     },
     /**
-     * Generates hex number with length 12
+     * Returns a random string of hex digits with length 'len'.
+     * @param len the length.
      */
-    random12digitsHex: function () {
-        return rangeRandomHex(0x100000000000, 0xFFFFFFFFFFFF);
+    randomHexString: function (len) {
+        var ret = '';
+        while (len--) {
+            ret += this.randomHexDigit();
+        }
+        return ret;
     }
 };
 

modules/xmpp/xmpp.js

  * @returns {string}
  */
 function generateUserName() {
-    return RandomUtil.random8digitsHex() + "-" + RandomUtil.random4digitsHex() + "-" +
-        RandomUtil.random4digitsHex() + "-" + RandomUtil.random8digitsHex();
+    return RandomUtil.randomHexString(8) + "-" + RandomUtil.randomHexString(4)
+        + "-" + RandomUtil.randomHexString(4) + "-"
+        + RandomUtil.randomHexString(8);
 }
 
 function connect(jid, password) {