Why Clojure's println does not print Unicode chars properly, while Java's println does?

Question

The repro is very simple, note the correct ║ with Java's println and incorrect ? with Clojure's println:

Clojure 1.10.3
user=> (.println System/out "abc\u2551")
abc║
nil
user=> (println "abc\u2551")
abc?
nil

Answer 1

Interesting, I have both correct in my case, in a fresh REPL started with just clj:

Clojure 1.10.3
user=> (.println System/out "abc\u2551")
abc║
nil
user=> (println "abc\u2551")
abc║
nil

Answer 2

I suspect the root cause of the difference might have to do with things like the operating system, the JDK version, whether the REPL is run inside of an IDE like VSCode with Calva, Emacs with CIDER, or at a terminal, and perhaps even environment variable settings used by the JVM for determining character sets like LC, LANG, TERM, etc. for macOS and Linux.

At least for macOS 10.14.6 built-in Terminal, AdoptOpenJDK 15.0.1, and a REPL started in that Terminal using clojure version 1.10.1.763 and the environment variable values below, I got the desired result:

$ env | egrep '(LC|LANG|TERM)' TERM_PROGRAM=Apple_Terminal TERM=xterm-256color TERM_PROGRAM_VERSION=421.2 TERM_SESSION_ID=51C20403-498A-4E4E-ABFE-B59367276B5D LANG=en_US.UTF-8

Answer 3

Interesting :-), here is more info about my system:
OS: Windows 10, version 21H1
Java:
java version "1.8.0_311" Java(TM) SE Runtime Environment (build 1.8.0_311-b11) Java HotSpot(TM) Client VM (build 25.311-b11, mixed mode)
Terminals:
I've tried 4 different terminals: cmd, PowerShell, VS Code's built-in term and ConEmu. The same result on all 4.
I've also tried clj from PowerShell, lein trampoline run and direct java -jar uberjar invocation, it never works properly with Clojure's println and always works for Java's.

Comments

I have the same problem... on Windows 10 21H1, JDK 16, clj 1.10.3.