Issue in Exit/Quit Command

[akhileshtripa]

I have written custom shell for my client application. My all commands are working fine except "Quit/Exit" command. When I Override Quit Command interface and write System.exit(0) inside my custom logic, entire sprint boot application goes down. please suggest?

[c4deszes]

By default the Quit command simply does:

spring-shell/spring-shell-standard-commands/src/main/java/org/springframework/shell/standard/commands/Quit.java

Line 46 in 296db93

throw new ExitRequest();

Which is then catched in the REPL cycle of the Shell.

spring-shell/spring-shell-core/src/main/java/org/springframework/shell/Shell.java

Lines 124 to 147 in 296db93

	public void run(InputProvider inputProvider) throws IOException {
	Object result = null;
	while (!(result instanceof ExitRequest)) { // Handles ExitRequest thrown from Quit command
	Input input;
	try {
	input = inputProvider.readInput();
	}
	catch (Exception e) {
	if (e instanceof ExitRequest) { // Handles ExitRequest thrown from hitting CTRL-C
	break;
	}
	resultHandler.handleResult(e);
	continue;
	}
	if (input == null) {
	break;
	}
	result = evaluate(input);
	if (result != NO_INPUT && !(result instanceof ExitRequest)) {
	resultHandler.handleResult(result);
	}
	}
	}

So calling quit/exit by default doesn't kill the application, it just stops the shell from the taking inputs from the command line interface. Note that run(InputProvider inputProvider) calls 'evaluate(Input input)' so if you have autowired the Shell into your application you can still call commands in your code.

If the only dependency you have is Spring Shell then your application should stop on an ExitRequest because it's the only Thread that was running. Once you have web or any other running thread then it's going to keep the application alive.

System.exit(0) tries to shutdown the JVM (all threads), if you don't want to close the application on the 'exit' command then don't override it. If you want it to close but gracefully then you could use SpringApplication.exit or ApplicationContext::close these will call close() on DisposableBean-s and @PreDestroy methods.

[BOFA1ex]

the error(ExitRequest&EndOffFileException) will be catch by org.springframework.shell.result.ThrowableResultHandler.
need to catch explicitly and break the loop.

Input input;
try {
    input = inputProvider.readInput();
    /*
    * change here
    * - add: keymap ctrl+c/d
    */
} catch (ExitRequest | EndOfFileException e) {
      break;
} catch (Exception e) {
      resultHandler.handleResult(e);
      continue;
}
if (input == null) {
      break;
}
result = evaluate(input);
if (result != NO_INPUT && !(result instanceof ExitRequest)) {
      resultHandler.handleResult(result);
}

[jvalkeal]

We're doing housekeeping in issues and closing ones which are potentially stale due to recent changes in a project. We are now more up to date with Spring Boot starting with release 2.1.0 and work in 3.x making shell compatible with Spring Framework 6 and Spring Boot 3.

If you think issue should not have been closed, try to re-open or open a new issue with updated info.