SpringBoot(10) Servlet3.0的注解：自定义原生Servlet、自定义原生Listener

一、自定义原生Servlet

1、启动类里面增加注解 @ServletComponentScan

2、Servlet上添加注解  @WebServlet(name = "userServlet",urlPatterns = "/v1/api/test/customs")

@WebServlet(name = "userServlet",urlPatterns = "/v1/api/test/customs")
public class UserServlet extends HttpServlet{

     @Override
     public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         
         resp.getWriter().print("custom sevlet");
         resp.getWriter().flush();
         resp.getWriter().close();
     }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        this.doGet(req, resp);
    }
    
}

二、自定义原生Listener

常用的监听器 servletContextListener、httpSessionListener、servletRequestListener

servletContextListener：服务启动，一般用于初始化加载

servletRequestListener：访问启动，一般用于统计

@WebListener
public class CustomContextListner implements ServletContextListener{

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("======contextInitialized========");
        //启动时触发
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("======contextDestroyed========");
        
    }

}

@WebListener
public class RequestListener implements ServletRequestListener {

    @Override
    public void requestDestroyed(ServletRequestEvent sre) {
        // TODO Auto-generated method stub
        System.out.println("======requestDestroyed========");
    }

    @Override
    public void requestInitialized(ServletRequestEvent sre) {
        System.out.println("======requestInitialized========");
        
    }

}