这个问题怎么解决？？

Question

已知如下的类TestPara:
inport java.util.*
inport java.io.*
inport javax.servlet.*
inport javax.servlet.http.*

public class TestPara extends HttpServlet{
int para=0 ;
protected void doPost(HttpServletRequest request,HttpServletResponse response)throws
java.io.I0Exception,javax.servlet.ServletException{
doGet(request,response);
}

protected void doGet(HttpServletRequest request,HttpServletResponse response)throws
java.io.I0Exception,javax.servlet.ServletException{
response.setContentType(“test/html”);
try{
para ++ ;
PrintStream out=new PrintStream(response,getOutputStream());
out.println(“”+ para) ;
out.flush();
out.close();
}catch(Exception e){}
}
}

在客户机A的浏览器中调用该类后，在客户机B的浏览中调用该类，然后关掉A的浏览器后再次打开，重新调用该类，
请写出3次调用的输出值？