SpringMVC 拦截器配置

Question

一. SpringMVC 拦截器

public class Interceptor implements HandlerInterceptor{
  private Logger logger = LoggerFactory.getLogger(Interceptor.class);

  public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
      throws Exception {
    // TODO Auto-generated method stub

  }

  public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
      throws Exception {
    // TODO Auto-generated method stub

  }

  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
    String flag = null;
    flag = request.getParameter("auth");
    if(StringUtils.isEmpty(flag) || !flag.equals("php")){
      /*logger.error("error-auth:{}", flag);
      response.getWriter().append("error-auth");
      return false;*/
    } else {
      logger.info("通过校验！");
      return true;
    }
    return true;
  }
}

向 SpringBoot 注册拦截器：

@Configuration
public class MyWebAppConfigurer implements WebMvcConfigurer {
  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(new Interceptor()).addPathPatterns("/**");
  }
}

二. Servlet 过滤器

/*
 * 如果是一个过滤器,在 MyFilter 类上加上 @WebFilter(filterName = "myFilter",urlPatterns = {"/*"}) ,入口类加上 @ServletComponentScan 即可
 */
public class MyFilter implements Filter{
  @Override
  public void init(FilterConfig filterConfig) throws ServletException {

  }

  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    System.out.println(request.getParameter("name"));
    HttpServletRequest hrequest = (HttpServletRequest)request;
    HttpServletResponseWrapper wrapper = new HttpServletResponseWrapper((HttpServletResponse) response);
    if(hrequest.getRequestURI().indexOf("/index") != -1 ||
        hrequest.getRequestURI().indexOf("/asd") != -1 ||
        hrequest.getRequestURI().indexOf("/online") != -1 ||
        hrequest.getRequestURI().indexOf("/login") != -1
        ) {
      chain.doFilter(request, response);
    }else {
//      wrapper.sendRedirect("/login");
      chain.doFilter(request, response);
    }
  }

  @Override
  public void destroy() {

  }
}

SpringBoot 项目配置过滤器：

@Configuration
public class MyWebAppConfigurer implements WebMvcConfigurer {
  /**
   * 注册过滤器
   * @return
   */
  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Bean
  public FilterRegistrationBean filterRegist() {
    FilterRegistrationBean frBean = new FilterRegistrationBean();
    frBean.setFilter(new MyFilter());
//    frBean.setOrder(1);//多个过滤器时指定过滤器的执行顺序
    frBean.addUrlPatterns("/*");
    System.out.println("filter");
    return frBean;
  }
}

三. Servlet 监听器

/**
 * @date: 2019/4/1
 * @description:  ServletRequestListener、 HttpSessionListener 、ServletContextListener ......
 * 可直接在 MyListener 类上使用 @WebListener 注解,入口类加上 @ServletComponentScan 即可
 */
public class MyListener implements HttpSessionListener {
  private Logger logger = LoggerFactory.getLogger(this.getClass());//用户 this.getClass(), 粘贴不容易出错
  public static int online = 0;

  @Override
  public void sessionCreated(HttpSessionEvent se) {
    online ++;
    logger.info("online 在线人数为：" + online);
  }

  @Override
  public void sessionDestroyed(HttpSessionEvent se) {

  }
}

SpringBoot 项目配置监听器：

@Configuration
public class MyWebAppConfigurer implements WebMvcConfigurer {
  /**
   * 注册监听器
   * @return
   */
  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Bean
  public ServletListenerRegistrationBean listenerRegist() {
    ServletListenerRegistrationBean srb = new ServletListenerRegistrationBean();
    srb.setListener(new MyListener());
    System.out.println("listener");
    return srb;
  }
}