Pass params to a running background java process via bash script

Question

I have a java application using switch-case in while loop to excute command. How can i pass params to a running background java process via bash script ?, I don't want to using socket or webUI to pass data. Here is my code:

    public static void main(String[] args) throws IOException {
    boolean eof = false;
    Scanner sc = new Scanner(System.in);
    while (!eof) {
        System.out.println("Enter your command!");
          String data = sc.useDelimiter("\\<end>").next();
        CommandField cmdF = gson.fromJson(data, CommandField.class);
        switch (Command.Parse(cmdF.getCommand())) {
            case LOGIN:
                result = client.isLogged();
                if (result) {
                    System.out.println("successful!");
                } else {
                    System.out.println("failed!");
                }
                break;
        }

}

Could you please clarify, what you mean with params and background process. Is this process already running or shall it be started with the parameters? — markusw, Dec 05 '18 at 09:34
process already running. I have edit my question. Thanks @markusw — Trung Nguyen, Dec 05 '18 at 09:37

score 0 · Answer 1 · answered Dec 05 '18 at 09:42

You can only pass variables to a running process by dedicated interfaces. To my mind come the following options:

JMX (https://alvinalexander.com/blog/post/java/source-code-java-jmx-hello-world-application)
HTTP (https://stackoverflow.com/a/52847756/1905015)
Socket (https://de.wikibooks.org/wiki/Java_Standard:_Socket_und_ServerSocket_(java.net))
Write to temp file, let the process look at that file and react to changes

But the program you want to pass the parameters to must provide an implementation of the interface. Otherwise there is no possibility to pass something if the process has no option to receive it.

Pass params to a running background java process via bash script

1 Answers1