原生注解方式注入web原生元件

• 使用原生注解注入servlet元件：@WebServlet處理請求路由，+主配置類中标注@ServletComponentScan掃描原生注解所在的路徑

@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("66666");
    }
}

@MapperScan("com.atguigu.admin.mapper")
@ServletComponentScan(basePackages = "com.atguigu.admin")
@SpringBootApplication(exclude = RedisAutoConfiguration.class)
public class Boot05WebAdminApplication {
    public static void main(String[] args) {
        SpringApplication.run(Boot05WebAdminApplication.class, args);
    }
}
``
 
- 使用原生注解注入filter元件：@WebFilter + @ServletComponentScan      

@Slf4j

@WebFilter(urlPatterns={"/css/","/images/"}) // 表示攔截該路徑下的靜态資源

public class MyFilter implements Filter {

@Override
public void init(FilterConfig filterConfig) throws ServletException {
    log.info("MyFilter初始化完成");
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    log.info("MyFilter工作");   // 攔截後進行邏輯處理
    chain.doFilter(request,response);   // 最後放行，放行後可通路
}

@Override
public void destroy() {
    log.info("MyFilter銷毀");
}      

}

- 使用原生元件注入listener元件：@WebListener + @ServletComponentScan      

@Slf4j

@WebListener

public class MyServletContextListener implements ServletContextListener {

@Override
public void contextInitialized(ServletContextEvent sce) {
    log.info("MySwervletContextListener監聽到項目初始化完成");
}

@Override
public void contextDestroyed(ServletContextEvent sce) {
    log.info("MySwervletContextListener監聽到項目銷毀");
}