Improved string utils class, added javaDocs

src/main/java/fr/xephi/authme/util/StringUtils.java

@@ -6,14 +6,23 @@ import net.ricecode.similarity.StringSimilarityServiceImpl;
 
 public class StringUtils {
 
+    /**
+     * Get the difference of two strings.
+     *
+     * @param first First string.
+     * @param second Second string.
+     *
+     * @return The difference value.
+     */
     public static double getDifference(String first, String second) {
+        // Make sure the strings are valid.
         if(first == null || second == null)
             return 1.0;
 
+        // Create a string similarity service instance, to allow comparison
         StringSimilarityService service = new StringSimilarityServiceImpl(new LevenshteinDistanceStrategy());
 
-        double score = service.score(first, second);
-
-        return Math.abs(score - 1.0);
+        // Determine the difference value, return the result
+        return Math.abs(service.score(first, second) - 1.0);
     }
 }