Prelimary stuff for REST error reporting

Change-Id: Ie562498d0a9394c3e839ceb463e9beab9e1ecff2
diff --git a/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java b/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java
new file mode 100644
index 0000000..edc39b2
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/rest/RestErrorFormatter.java
@@ -0,0 +1,32 @@
+package net.onrc.onos.api.rest;
+
+import org.slf4j.helpers.FormattingTuple;
+import org.slf4j.helpers.MessageFormatter;
+
+/**
+ * Utility class used for formatting Rest Error descriptions.
+ */
+public final class RestErrorFormatter {
+
+    /**
+     * Hide default constructor for utility classes.
+     */
+    private RestErrorFormatter() { }
+
+    /**
+     * Takes a RestError template and formats the description using a supplied
+     * list of replacement parameters.
+     *
+     * @param error the RestError to format
+     * @param parameters parameter list to use as positional parameters in the
+     *                   result string
+     *
+     * @return the String object for the formatted message.
+     */
+    static String formatErrorMessage(final RestError error,
+                                     final Object... parameters) {
+        final FormattingTuple formattingResult =
+                MessageFormatter.arrayFormat(error.getDescription(), parameters);
+        return formattingResult.getMessage();
+    }
+}