@WebServlet
通过使用注解,省去了去xml中配置的这一项,大大减轻工作量
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/anno") public class AnnotationServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.getWriter().print("这是一个 Annotation Servlet"); } }
在启动时就加载,提升运行速度
<load-on-startup>
设置启动加载<load-on-startup>
0~9999<、load-on-startup>
此处设置了
loadOnStartup
,同时还是必须设置urlPatterns
地址才可以。
CreateServlet
@WebServlet(urlPatterns = "/create", loadOnStartup = 0) public class CreateServlet extends HttpServlet { @Override public void init() throws ServletException { System.out.println("正在创建数据库"); } }
ImportServlet
@WebServlet(urlPatterns = "/import", loadOnStartup = 1) public class ImportServlet extends HttpServlet { @Override public void init() throws ServletException { System.out.println("正在导入数据..."); } }
AnalysisServlet
@WebServlet(urlPatterns = "/analysis", loadOnStartup = 2) public class AnalysisServlet extends HttpServlet { @Override public void init() throws ServletException { System.out.println("正在分析数据..."); } }
Servlet在启动的时候就进行了加载,常用作服务的启动加速