7. Thread-Per-Message模式

这项工作就交给你了

public class Main{
    public static void main(String[] args){
        System.out.println("main BEGIN");
        Host host = new Host();
        host.request(10,'A');
        host.request(20,'B');
        host.request(30,'C');
        System.out.println("main END");
    }
}