// 1. 注冊(cè)Servlet（作為Spring Bean）
@Component
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("MyServlet Auto Registered");
    }
}

// 2. 注冊(cè)Filter（作為Spring Bean）
@Component
public class MyFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("MyFilter Auto Filtering");
        chain.doFilter(request, response);
    }
}

// 3. 注冊(cè)Listener（作為Spring Bean）
@Component
public class MyListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("ServletContext Initialized (Auto Registered)");
    }
}

@Configuration
public class WebConfig {
    // 注冊(cè)Filter，自定義路徑和初始化參數(shù)
    @Bean
    public FilterRegistrationBean<MyFilter> myFilterRegistrationBean() {
        FilterRegistrationBean<MyFilter> registrationBean = new FilterRegistrationBean<>();
        registrationBean.setFilter(new MyFilter()); // 設(shè)置Filter實(shí)例
        registrationBean.addUrlPatterns("/api/*"); // 自定義映射路徑（僅攔截/api下的請(qǐng)求）
        registrationBean.setInitParameter("filterName", "myFilter"); // 初始化參數(shù)
        registrationBean.setOrder(1); // 設(shè)置加載順序（值越小，加載越早）
        return registrationBean;
    }

    // 注冊(cè)Servlet，自定義路徑和初始化參數(shù)
    @Bean
    public ServletRegistrationBean<MyServlet> myServletRegistrationBean() {
        ServletRegistrationBean<MyServlet> registrationBean = new ServletRegistrationBean<>();
        registrationBean.setServlet(new MyServlet());
        registrationBean.addUrlMappings("/myServlet/custom"); // 自定義映射路徑
        registrationBean.setInitParameter("servletName", "myServlet");
        registrationBean.setLoadOnStartup(1); // 啟動(dòng)時(shí)加載
        return registrationBean;
    }

    // 注冊(cè)Listener
    @Bean
    public ServletListenerRegistrationBean<MyListener> myListenerRegistrationBean() {
        ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>();
        registrationBean.setListener(new MyListener());
        return registrationBean;
    }
}

// 用@ServletRegistration注冊(cè)Servlet，替代ServletRegistrationBean
@ServletRegistration(urlPatterns = "/myServlet/annotation", loadOnStartup = 1)
@Component
public class MyServlet extends HttpServlet {
    // 實(shí)現(xiàn)邏輯...
}

// 用@FilterRegistration注冊(cè)Filter，替代FilterRegistrationBean
@FilterRegistration(urlPatterns = "/api/*", initParams = {@InitParam(name = "filterName", value = "myFilter")})
@Component
public class MyFilter implements Filter {
    // 實(shí)現(xiàn)邏輯...
}

// 1. 啟動(dòng)類(lèi)添加@ServletComponentScan，指定掃描包（可選，默認(rèn)掃描當(dāng)前包及子包）
@SpringBootApplication
@ServletComponentScan(basePackages = "com.example.web.component")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

// 2. 用@WebServlet注冊(cè)Servlet
@WebServlet(urlPatterns = "/webServlet", name = "WebServletDemo", loadOnStartup = 1)
public class WebServletDemo extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("WebServlet Annotated Registered");
    }
}

// 3. 用@WebFilter注冊(cè)Filter
@WebFilter(urlPatterns = "/web/*", filterName = "WebFilterDemo")
public class WebFilterDemo implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("WebFilter Annotated Filtering");
        chain.doFilter(request, response);
    }
}

// 4. 用@WebListener注冊(cè)Listener
@WebListener
public class WebListenerDemo implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("ServletContext Initialized (WebListener Annotated)");
    }
}