SpringBoot配置嵌入式服务器的实操演示

<!-- 传统web.xml配置Servlet -->
<servlet>
    <servlet-name>myServlet</servlet-name>
    <servlet-class>com.example.MyServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>myServlet</servlet-name>
    <url-pattern>/myServlet</url-pattern>
</servlet-mapping>

// 1. 自定义Servlet：处理请求
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        resp.getWriter().write("Hello MyServlet!"); // 响应内容
        System.out.println("MyServlet处理了GET请求");
    }
}
// 2. 自定义Filter：过滤请求
public class MyFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("MyFilter执行前");
        chain.doFilter(request, response); // 放行请求
        System.out.println("MyFilter执行后");
    }
}
// 3. 自定义Listener：监听Servlet容器事件（如启动、关闭）
public class MyListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("MyListener：Servlet容器初始化完成");
    }
    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("MyListener：Servlet容器销毁");
    }
}

@Configuration
public class ServletConfig {
    // 注册Servlet
    @Bean
    public ServletRegistrationBean<MyServlet> myServlet() {
        // 关联自定义Servlet，并指定访问路径为/myServlet
        ServletRegistrationBean<MyServlet> registrationBean = new ServletRegistrationBean<>(new MyServlet(), "/myServlet");
        registrationBean.setLoadOnStartup(1); // 启动顺序（数字越小越先启动）
        return registrationBean;
    }
    // 注册Filter
    @Bean
    public FilterRegistrationBean<MyFilter> myFilter() {
        FilterRegistrationBean<MyFilter> registrationBean = new FilterRegistrationBean<>();
        registrationBean.setFilter(new MyFilter()); // 关联自定义Filter
        // 指定过滤路径：拦截/hello和/myServlet的请求
        registrationBean.setUrlPatterns(Arrays.asList("/hello", "/myServlet"));
        return registrationBean;
    }
    // 注册Listener
    @Bean
    public ServletListenerRegistrationBean<MyListener> myListener() {
        // 关联自定义Listener
        ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener());
        return registrationBean;
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class TestController {
    // 该路径会被MyFilter过滤（因为Filter配置了拦截/hello）
    @GetMapping("/hello")
    public String hello() {
        System.out.println("TestController的/hello方法执行");
        return "hello";
    }
}

MyListener：Servlet容器初始化完成

MyFilter执行前
MyServlet处理了GET请求
MyFilter执行后

MyFilter执行前
TestController的/hello方法执行
MyFilter执行后

server.servletPath=/app/*  # 修改为拦截/app/*路径