RFR: 8352693: Use a simpler console reader instead of JLine for System.console()

[Jan Lahoda]

On Thu, 27 Mar 2025 18:28:17 GMT, Naoto Sato <naoto at openjdk.org> wrote:

>> The `java.io.Console` has several backends: a simple on in `java.base`, a more convenient one in `jdk.internal.le` (with line-reading based on JLine) and one for JShell.
>> 
>> The backend based on JLine is proving to be a somewhat problematic - JLine is very powerful, possibly too powerful and complex for the simple task of editing a line with no completion, no history, no variables, no commands, etc. As a consequence, there are inevitable sharp edges in this backend.
>> 
>> The idea in this PR is to replace the use of JLine in the `jdk.internal.le` backend with a simple escape code interpreter, that only handles a handful of keys/codes (left/right arrow, home, end, delete, backspace, enter), and ignores the rest. The goal is to have something simple with less surprising behavior.
>
> src/jdk.internal.le/share/classes/jdk/internal/console/SimpleConsoleReader.java line 69:
> 
>> 67:                 case 4: break READ; //EOF/Ctrl-D
>> 68:                 case 127:
>> 69:                     //backspace:
> 
> Is it `delete`?

I don't think so. Delete is an escape sequence (`\033[3~`).

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PR Review Comment: https://git.openjdk.org/jdk/pull/24242#discussion_r2021413402