Run Java 11 online

What's in Java 11

• JEP 321: standard HTTP client (java.net.http) — no more Apache HTTP for basic calls.
• JEP 323: local-variable syntax for lambda parameters (`(var x, var y) -> ...`).
• JEP 330: launch single-file source-code programs (`java Hello.java`).

What you get in Java 11

Clicking "Run now" opens the playground with this exact code and a matching test case — passes on first Run.

import java.util.Scanner;
public class Solution {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    System.out.println(n * 2);
  }
}

How ls-judge runs Java 11

Every submission is compiled and executed inside its own Firecracker microVM — the same isolation primitive AWS Lambda uses. No shared container, no shared kernel with other users' code. The Java 11toolchain shipped with the microVM is the real thing (not a browser-side emulation): syscalls behave the way they do in production, and the compile / runtime behaviour matches what you would see on your own machine with that version installed.

Feed stdin from the Tests panel, watch verdicts stream per test case over a WebSocket. Free to use, no sign-up, works from any browser.