From a804c5e4316b7f883d8aa0c689b431ea8cfb5d32 Mon Sep 17 00:00:00 2001
From: Cyril de Catheu <cyril@startree.ai>
Date: Sun, 7 Jan 2024 00:11:31 +0100
Subject: [PATCH] improve exception message in DateTimeFormatter (#731)

Co-authored-by: Stephen Colebourne <scolebourne@joda.org>
---
 src/main/java/org/joda/time/format/DateTimeFormat.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/org/joda/time/format/DateTimeFormat.java b/src/main/java/org/joda/time/format/DateTimeFormat.java
index 89bb54d31..b3f7ab681 100644
--- a/src/main/java/org/joda/time/format/DateTimeFormat.java
+++ b/src/main/java/org/joda/time/format/DateTimeFormat.java
@@ -679,7 +679,7 @@ private static boolean isNumericToken(String token) {
      */
     private static DateTimeFormatter createFormatterForPattern(String pattern) {
         if (pattern == null || pattern.length() == 0) {
-            throw new IllegalArgumentException("Invalid pattern specification");
+            throw new IllegalArgumentException("Invalid pattern specification. Pattern is null or empty.");
         }
         DateTimeFormatter formatter = cPatternCache.get(pattern);
         if (formatter == null) {