整合Servlet、Filter、Listener(SpringBoot)

一般情況下, 使用Spring, SpringMVC 這些框架之後, 基本上就告別Servlet、Filter、Listener了, 但是有時候整合一些第三方框架時, 可能還是不得不使用Servlet、Filter、Listener。

• 整合Servlet

使用@WebServlet("/my")註解

@WebServlet("/my")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
        System.out.println("MyServlet>>>doGet");
        doPost(req,resp);
    }

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

}

• 整合Filter

@WebFilter("/*")
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("MyFilter>>>init");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("MyFilter>>>doFilter");
        filterChain.doFilter(servletRequest, servletResponse);
    }

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

• 整合Litener

• @WebListener
  public class MyListener implements ServletRequestListener {
      @Override
      public void requestDestroyed(ServletRequestEvent sre) {
          System.out.println("MyListener>>>requestDestroyed");
      }
  
      @Override
      public void requestInitialized(ServletRequestEvent sre) {
          System.out.println("MyListener>>>requestInitialized");
      }
  }

  最關鍵的一步是啓動這些配置, 需要告訴程序, 

  @SpringBootApplication
  //添加註解, 進行配置掃描
  @ServletComponentScan
  public class App {
  
      public static void main(String[] args) {
          SpringApplication.run(App.class, args);
      }
  
  }