web.xml配置

DateServlet.class
public class DateServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    Date date = new Date();
    String data = sdf.format(date);
    resp.getOutputStream().write(data.getBytes());
}
}
web.xml
<servlet>
//定义servlet的名字
<servlet-name>dateServlet</servlet-name>
//Tomcat会根据该值反射创建servlet对象 
<servlet-class>com.neu.day01.DateServlet</servlet-class>
</servlet>
//配置当前servlet能处理怎样的url请求
<servlet-mapping>
<servlet-name>dateServlet</servlet-name>
<url-pattern>/dateServlet</url-pattern>
</servlet-mapping>

结果