2021-11-02 java | Clojure Slack Archive

java

West 2021-11-02T15:35:40.003200Z

Did I just discover a bug in the java standard library?

(ns scratchpad
  (:import java.text.SimpleDateFormat
           (java.time Instant Locale ZoneOffset)
           java.time.format.DateTimeFormatter
           java.util.Date))

(def pattern-1 "EEE, dd MMM yyyy HH:mm:ss ZZZZ")
(def pattern-2 "EEE, dd MMM yyyy HH:mm:ss ZZ")

(defn format-time [t pat]
  (when t
    (cond
      (instance? Date t)
      (.format (new SimpleDateFormat
                    pat
                    Locale/ENGLISH) t)
      (instance? Instant t)
      (.format (DateTimeFormatter/ofPattern pat Locale/ENGLISH)
               (.atOffset t ZoneOffset/UTC)))))

(let [inst (Instant/now)
      date (Date/from inst)]
  [[(format-time inst pattern-1) (format-time date pattern-1)]
   [(format-time inst pattern-2) (format-time date pattern-2)]])

Expected:

=> [["Tue, 02 Nov 2021 05:52:02 +0000" "Tue, 02 Nov 2021 05:52:02 +0000"]
    ["Tue, 02 Nov 2021 05:52:02 +0000" "Tue, 02 Nov 2021 05:52:02 +0000"]]

Actual:

=> [["Tue, 02 Nov 2021 05:52:02 GMT"   "Tue, 02 Nov 2021 05:52:02 +0000"]
    ["Tue, 02 Nov 2021 05:52:02 +0000" "Tue, 02 Nov 2021 05:52:02 +0000"]]

According to the https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/format/DateTimeFormatter.html, "Z" in a pattern should not yield a localized zone offset.

Colin P. Hill 2021-11-03T12:37:47.005600Z

Looks right to me (emphasis mine) > Offset Z: This formats the offset based on the number of pattern letters. One, two or three letters outputs the hour and minute, without a colon, such as '+0130'. The output will be '+0000' when the offset is zero. Four letters outputs the https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/format/TextStyle.html#FULL form of localized offset, equivalent to four letters of Offset-O. The output will be the corresponding localized offset text if the offset is zero. Five letters outputs the hour, minute, with optional second if non-zero, with colon. It outputs 'Z' if the offset is zero. Six or more letters throws IllegalArgumentException.

West 2021-11-03T13:20:08.005800Z

Damn, that makes me look dumb. Yet again I’m defeated by just skimming and not reading.

2021-11-02T15:36:43.003800Z

java.util.Date is cursed

2021-11-02T15:37:25.004300Z

easily my least favorite class 🙂

West 2021-11-02T15:37:54.004800Z

I discovered this while switching to the new java.time API.

2021-11-02T15:39:25.005Z

oh yeah I see what you mean

West 2021-11-02T15:40:26.005300Z

Nice name by the way @danielmartincraig

2021-11-02T15:40:32.005500Z

lol thank you

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