From f8a6ee542d76cba7d5ac3e2672d2a895212d72c7 Mon Sep 17 00:00:00 2001
From: Basil Crow <me@basilcrow.com>
Date: Sat, 30 Mar 2024 06:23:47 -0700
Subject: [PATCH] Deprecate `Util#RFC822_DATETIME_FORMATTER` (#9085)

---
 core/src/main/java/hudson/Functions.java | 5 ++++-
 core/src/main/java/hudson/Util.java      | 5 +++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/hudson/Functions.java b/core/src/main/java/hudson/Functions.java
index ac734f490e..6ebe09dd88 100644
--- a/core/src/main/java/hudson/Functions.java
+++ b/core/src/main/java/hudson/Functions.java
@@ -117,6 +117,9 @@ import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.text.DateFormat;
 import java.text.DecimalFormat;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -235,7 +238,7 @@ public class Functions {
     }
 
     public static String rfc822Date(Calendar cal) {
-        return Util.RFC822_DATETIME_FORMATTER.format(cal.getTime());
+        return DateTimeFormatter.RFC_1123_DATE_TIME.format(ZonedDateTime.ofInstant(cal.toInstant(), ZoneId.systemDefault()));
     }
 
     /**
diff --git a/core/src/main/java/hudson/Util.java b/core/src/main/java/hudson/Util.java
index 24b04ce308..340a717067 100644
--- a/core/src/main/java/hudson/Util.java
+++ b/core/src/main/java/hudson/Util.java
@@ -84,6 +84,7 @@ import java.text.NumberFormat;
 import java.text.ParseException;
 import java.time.LocalDate;
 import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
 import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -1875,6 +1876,10 @@ public class Util {
     public static final FastDateFormat XS_DATETIME_FORMATTER = FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss'Z'", new SimpleTimeZone(0, "GMT"));
 
     // Note: RFC822 dates must not be localized!
+    /**
+     * @deprecated use {@link DateTimeFormatter#RFC_1123_DATE_TIME}
+     */
+    @Deprecated
     public static final FastDateFormat RFC822_DATETIME_FORMATTER
             = FastDateFormat.getInstance("EEE, dd MMM yyyy HH:mm:ss Z", Locale.US);