SpringBoot2.1.X Servlet3.0注解自定义原生Servlet和Listener

向右看齐 2024-04-18 23:58 33阅读 0赞

### **1、自定义原生Servlet** ###

/**
     * servlet注解
     */
    @WebServlet(urlPatterns = "/servlet/test", name = "TestServlet")
    public class TestServlet extends HttpServlet {
        public TestServlet() {
            super();
            System.out.println("servlet constructor!");
        }
    
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            System.out.println("servlet doGet");
           //页面输出信息
            resp.getWriter().print("hello test sevlet!");
            //刷新
            resp.getWriter().flush();
            //关闭
            resp.getWriter().close();
        }
    
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          //调用doGet方法
            doGet(req, resp);
        }
    
        @Override
        public void destroy() {
            System.out.println("servlet destroy");
        }
    
        @Override
        public void init(ServletConfig config) throws ServletException {
            super.init(config);
            System.out.println("servlet init");
    
        }
    }

注意：必须在启动项配置ServletComponentScan注解扫描

@ServletComponentScan    //必须要注解扫描哦！
    public class NewdemoApplication {
    
    }

效果

![20190914184828785.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70][]

### **2.自定义原生Listener监听器** ###

/**
     * 监听器注解   ==>先注释了Filter
     */
    @WebListener()
    public class MyListener implements ServletContextListener,
            HttpSessionListener, ServletRequestListener {
    
        // Public constructor is required by servlet spec
        public MyListener() {
            System.out.println("MyListener constructor!");
        }
    
        // -------------------------------------------------------
        // ServletContextListener implementation
        // -------------------------------------------------------
        public void contextInitialized(ServletContextEvent sce) {
          /* This method is called when the servlet context is
             initialized(when the Web application is deployed). 
           You can initialize servlet context related data here.
          */
            System.out.println("MyListener contextInitialized 上下文！");
        }
    
        public void contextDestroyed(ServletContextEvent sce) {
          /* This method is invoked when the Servlet Context 
             (the Web application) is undeployed or 
             Application Server shuts down.
          */
            System.out.println("MyListener contextDestroyed 上下文！");
        }
    
        // -------------------------------------------------------
        // HttpSessionListener implementation
        // -------------------------------------------------------
        public void sessionCreated(HttpSessionEvent se) {
            /* Session is created. */
            System.out.println("MyListener sessionCreated");
        }
    
        public void sessionDestroyed(HttpSessionEvent se) {
            /* Session is destroyed. */
            System.out.println("MyListener sessionDestroyed");
        }
    
    
        @Override
        public void requestDestroyed(ServletRequestEvent sre) {
            System.out.println("MyListener requestDestroyed");
        }
    
        @Override
        public void requestInitialized(ServletRequestEvent sre) {
              System.out.println("MyListener requestInitialized");
        }
    }

controller类测试

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1][]

效果:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3][]

[20190914184828785.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/1e421ea9860c40ccbc8d1ac048ab6a37.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/92a5c0e3690b48908d01ca80cbe953e4.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/49f508d7787c40a184d7fef967acf189.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/fe6cb48ca365408aaea5375cecb4b742.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/33cee2a7fa7a416fb8a622dacbebe881.png