后台进程与控制台交互的代码

本人在Eclipse里用代码在后台开启一个终端，然后将命令传入，然后再讲结果输出到控制台，但是有些命令需要你二次确认，本人理解就是终端重新开了另一个进程。这时，我写的代码就混乱了。
比如，输入某个命令时，显示

Start it from the beginning? (y or n) Please answer y or n.

此时，需要你在该句后面输入“y”或“n”才能继续。

我的代码如下：

    public void callBackCommand(Process tvm, String command) {

    MessageConsoleStream printer = ConsoleFactory1.getConsole().newMessageStream();
    printer.setActivateOnWrite(true);
    printer.println(command);

    BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(tvm.getOutputStream()));

    try {
        bw.flush();
        bw.write(command + " \n");
        bw.flush();
        InputStream is = tvm.getInputStream();
        InputStreamReader isr = null;
        isr = new InputStreamReader(is, "UTF-8");
        BufferedReader in = new BufferedReader(isr);
        String line = null;
        while ((line = in.readLine()) != null) {
            printer.println(line + "\n");
        }
        InputStream isE = tvm.getErrorStream();
        InputStreamReader isrE = null;
        isrE = new InputStreamReader(isE, "UTF-8");
        BufferedReader err = new BufferedReader(isrE);
        String lineE = null;
        while ((lineE = err.readLine()) != null) {
            printer.println(lineE + "\n");
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

请问要实现我的需求，应该怎么写？我的需求就是，怎么在Eclispe用代码和后台终端交互。有链接资料也可，拜谢。。。。

参考：https://blog.csdn.net/jsphnld/article/details/84415335

Scanner scanner=new Scanner(System.in);
        A:while(true){
            String str=scanner.nextLine().trim();
            //如果为空,则忽略此次输入
            if(str.isEmpty()){
                continue;
            }
            switch (str){
                case "q":{
                    System.out.println("结束");
                    break A;
                }
                default:{
                    System.out.println("无法识别指令:"+str);
                }
            }
        }