10.3.13、Servlet、Filter、Listener注入方式二

1、 MyServlet
```java package com.wzy.springbootweb02.servlet;

@WebServlet(name = “MyServlet”, value = “/myServlet”)//,urlPatterns = “/my” public class MyServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.getWriter().write(“111111”); }

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}

}

<br />2、MyFilter 过滤器。

```java
package com.wzy.springbootweb02.servlet;

@Slf4j//日志注解
@WebFilter(urlPatterns = {"/css/*","/imsges/*"})//Filter过滤器注解
public class MyFilter implements Filter {
    //初始化方法。
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("MyFilter初始化完成。");

    }

    //过滤逻辑
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        log.info("MyFilter运行。");
        filterChain.doFilter(servletRequest,servletResponse);//Filter放行
    }
    //销毁方法
    @Override
    public void destroy() {
        log.info("MyFilter销毁了。");
    }
}

3、MyServletContextListener 监听器。

package com.wzy.springbootweb02.servlet;

@Slf4j
@WebListener
public class MyServletContextListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        log.info("MyServletContextLister监听到项目初始化完成。");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        log.info("MyServletContextLister监听到项目销毁。");
    }
}

4、通过配置文件类的方式：@Configuration 要使用单实例方式。

@Configuration
public class MyRegistConfig {

    //servlet
    @Bean
    public ServletRegistrationBean myServlet(){
        MyServlet myServlet = new MyServlet();
        return new ServletRegistrationBean(myServlet,"/my","/my02");//拦截路径
    }

    //过滤器
    @Bean
    public FilterRegistrationBean myFilter(){
        MyFilter myFilter = new MyFilter();
        //myServlet拦截哪些路径，myFilter就拦截哪些路径。
       // return new FilterRegistrationBean(myFilter,myServlet());

        //自定义拦截路径。
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myFilter);
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/my","/css/*"));
        return filterRegistrationBean;
    }

    //监听器
    @Bean
    public ServletListenerRegistrationBean myList(){
        MyServletContextListener myServletContextListener = new MyServletContextListener();
        return new ServletListenerRegistrationBean(myServletContextListener);
    }

}