老师让写一个事件驱动系统，没学过C++，想用java写，有点看不懂题目，各位帮忙分析下。。

我也没太理解..
package gaga;
import java.util.*;
import java.io.*;

public class eventdriver {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
EventStart a = new EventStart();
a.Add();
}

}

class EventHandler
{
public static void add()
{
int a,b,c;
System.out.println("input two numbers:");
Scanner input = new Scanner(System.in);
a=input.nextInt();
b=input.nextInt();
c=a+b;
System.out.println("The result is:"+c);
}
public static void sub()
{
int a,b,c;
System.out.println("input two numbers:");
Scanner input = new Scanner(System.in);
a=input.nextInt();
b=input.nextInt();
c=a-b;
System.out.println("The result is:"+c);
}
}
abstract class EventHandlerList
{
public abstract void Add();
public abstract void PrepareEvent();
public abstract void Dispatch();
}
class EventStart extends EventHandlerList
{
private char a;
@Override
public void Add() {
// TODO Auto-generated method stub
while(true){
System.out.println("select an operation(+,-,q)");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter characters, 'q' to quit.");
// read characters
try {
a = (char) br.read();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
PrepareEvent();
}
}
@Override
public void Dispatch() {
// TODO Auto-generated method stub
}
@Override
public void PrepareEvent() {
// TODO Auto-generated method stub
switch(a){
case '+':EventHandler.add();break;
case '-':EventHandler.sub();break;
case 'q':break;
}
}

}

这个好像用C#方便！

cqupt？？