SpringBoot 整合Servlet、Filter和Listener

一般情况下，使用Spring、Spring MVC这些框架之后，基本上就告别Servlet、Filter以及Listener了，但是有时在整合一些第三方框架时，可能还是不得不使用Servlet。Spring Boot中对于整合这些基本的Web组件也提供了很好的支持。

添加如下三个组件：

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

@WebFilter("/*")
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) {
        System.out.println("MyFilter>>>init");
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("MyFilter>>>doFilter");
        chain.doFilter(request, response);
    }
 
    @Override
    public void destroy() {
        System.out.println("MyFilter>>>destroy");
    }
}

@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");
    }
}