Spring Boot 整合Web三大基础组件

博客主页：我的主页
欢迎点赞  收藏 留言  欢迎讨论！
本文由 【泠青沼~】 原创，首发于 CSDN
由于博主是在学小白一枚，难免会有错误，有任何问题欢迎评论区留言指出，感激不尽！个人主页

 一、Web三大基础组件

 1.1、编写MyServlet 1.2、编写MyFilter 1.3、编写MyListener

ServletListenerFilter  1.1、编写MyServlet

@WebServlet(urlPatterns = "/hello")//注解非常重要
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Servlet");
    }
}

@WebFilter(urlPatterns = "/*")//拦截所有请求
public class WebFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("WebFilter");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {
        System.out.println("destroy");
    }
}

@WebListener()
public class WebListener extends RequestContextListener {
    @Override//请求初始化
    public void requestInitialized(ServletRequestEvent requestEvent) {
        System.out.println("requestInitialized");
    }

    @Override//请求销毁
    public void requestDestroyed(ServletRequestEvent requestEvent) {
        System.out.println("requestDestroyed");
    }
}

拥有这三个类显然是不够的，必须要将这几个类都扫描进容器中，否则不起任何作用，需要一个非常重要的注解@ServletComponentScan加在启动类的上面，其中填入Web组件的目录包的位置，就可以正常使用

@SpringBootApplication
@ServletComponentScan("com.dong.webcomponent")
public class WebComponentApplication {

    public static void main(String[] args) {
        SpringApplication.run(WebComponentApplication.class, args);
    }

}