Gitpod: [Java] `jshell` doesn't work (no user input possible)

[jankeromnes]

Describe the bug
When you try to run jshell, the CLI starts, but then refuses to take any user input:

Even ^C or ^D don't work, the only way to kill it is to open another Terminal and run killall jshell.

Originally reported here.

To Reproduce

1. In any Gitpod workspace, run sdk use java 9.0.4-open (install if necessary)
2. Run jshell
3. Try to type anything into it. Nothing works.

Expected behavior
jshell should work.

I wonder if this is a bug with https://github.com/eclipse-theia/theia or even https://github.com/xtermjs/xterm.js.

[jankeromnes]

As a workaround, I found that you can pipe commands to it:

$ echo "/help" | jshell
Picked up JAVA_TOOL_OPTIONS: -Xmx2254m
|  Welcome to JShell -- Version 9.0.4
|  For an introduction type: /help intro

jshell> /help
|  Type a Java language expression, statement, or declaration.
|  Or type one of the following commands:
[...]
$ 

It runs the command and then exits, giving back control of the Terminal.

[JesterOrNot]

@jankeromnes can you send a repo with it installed

[jankeromnes]

@JesterOrNot jshell is part of Java by default (at least Java 9). The reproduction instructions work in every Gitpod workspace.

[JesterOrNot]

Sorry my bad!

[JesterOrNot]

It doesn't seem to be there

[jankeromnes]

Ah, so it's not in the default Java version.

But if you run sdk use java 9.0.4-open first, you'll have jshell.

[JesterOrNot]

[jankeromnes]

Then you can press Enter to install Java 9. :)