java如何覆盖GenericServlet？

Question

这是我的密码

public class hi extends GenericServlet{
    public void init(ServletConfig parm1){

    }

    @Override
    public void service(ServletRequest req,ServletRequest res){
        PrintWriter pw = res.getWriter();
        pw.println("hi");
    }
}

当我尝试编译它时：

hi.java:16: error: hi is not abstract and does not override abstract method service(ServletRequest,ServletResponse) in GenericServlet
public class hi extends GenericServlet{
       ^
hi.java:21: error: method does not override or implement a method from a supertype
    @Override
    ^
hi.java:23: error: cannot find symbol
        PrintWriter pw = res.getWriter();
                            ^
  symbol:   method getWriter()
  location: variable res of type ServletRequest
3 errors  

我想我已经重写了GenericServlet的service方法，但编译器确实得到了它，这让我很困惑

Answer 1

服务方法的第二个参数应该是ServletResponse