吕滔博客

为了那所谓的效率，试用了一下undertow容器，之前在tomcat容器下可以正常拦截的广告代码，在undertow下居然无效了...
费话不多说，直接上代码
错误提示:

ERROR io.undertow.request - [handleThrowable,80] - UT005023: Exception handling request to /druid/js/common.js
java.lang.IllegalStateException: UT010019: Response already commited
at io.undertow.servlet.spec.ServletOutputStreamImpl.resetBuffer(ServletOutputStreamImpl.java:748)
at io.undertow.servlet.spec.HttpServletResponseImpl.resetBuffer(HttpServletResponseImpl.java:514)
at javax.servlet.ServletResponseWrapper.resetBuffer(ServletResponseWrapper.java:190)
at javax.servlet.ServletResponseWrapper.resetBuffer(ServletResponseWrapper.java:190)
at com.dhecp.framework.config.DruidConfig$1.doFilter(DruidConfig.java:109)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)

tomcat下有效的代码

  /**
   * 去除监控页面底部的广告
   */
  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Bean
  @ConditionalOnProperty(name = "spring.datasource.druid.statViewServlet.enabled", havingValue = "true")
public FilterRegistrationBean removeDruidFilterRegistrationBean(DruidStatProperties properties)
{
    // 获取web监控页面的参数
    DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();
    // 提取common.js的配置路径
    String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";
    String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");
    final String filePath = "support/http/resources/js/common.js";
        // 创建filter进行过滤
   Filter filter = new Filter()
        {
            @Override
       public void init(javax.servlet.FilterConfig filterConfig) throws ServletException
            {
            }
            @Override
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
                throws IOException, ServletException
        {
            chain.doFilter(request, response);
            // 重置缓冲区，响应头不会被重置
            response.resetBuffer();
            // 获取common.js
            String text = Utils.readFromResource(filePath);
            // 正则替换banner, 除去底部的广告信息
            text = text.replaceAll("<a.*?banner\"></a><br/>", "");
            text = text.replaceAll("powered.*?shrek.wang</a>", "");
            response.getWriter().write(text);
        }
        @Override
        public void destroy()
        {
        }
    };
    FilterRegistrationBean registrationBean = new FilterRegistrationBean();
    registrationBean.setFilter(filter);
    registrationBean.addUrlPatterns(commonJsPattern);
    return registrationBean;
}

Undertow下有效的方法

 @Bean
    @ConditionalOnProperty(name = "spring.datasource.druid.statViewServlet.enabled", havingValue = "true")
    public FilterRegistrationBean<DruidAdFilter> druidAdFilterRegistration() {
        FilterRegistrationBean<DruidAdFilter> registration = new FilterRegistrationBean<>();
        registration.setFilter(new DruidAdFilter());
        // 设置过滤器匹配的URL模式
        registration.addUrlPatterns("/druid/js/common.js");
        // 设置过滤器的顺序
        registration.setOrder(Integer.MIN_VALUE);
        return registration;
    }

    @WebFilter(filterName = "druidWebStatFilter", urlPatterns = "/druid/*")
    public static class DruidAdFilter implements Filter {

        private String processedJs;

        @Override
        public void init(javax.servlet.FilterConfig filterConfig) throws ServletException {
            try {
                // 在初始化时加载和处理JS文件，避免每次请求都进行读取和处理
                ClassPathResource resource = new ClassPathResource("support/http/resources/js/common.js");
                byte[] bytes = FileCopyUtils.copyToByteArray(resource.getInputStream());
                String originalJs = new String(bytes);
                //processedJs = originalJs.replaceAll("<a.*?banner\"></a><br/>", "").replaceAll("powered.*?shrek.wang</a>", "");
                // 定义要匹配的正则表达式
                String pattern = "<footer class=\"footer\">([\\s\\S]*?)</footer>";
                // 编译正则表达式
                processedJs = Pattern.compile(pattern).matcher(originalJs).replaceAll("");;
            } catch (IOException e) {
                throw new ServletException("Failed to load js/common.js", e);
            }
        }

        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
            // 使用自定义响应包装器捕获响应输出
            chain.doFilter(request, response);
            // 确保仅在需要替换JS内容时才重写响应
            if (response.getContentType() != null && response.getContentType().contains("javascript")) {
                response.getWriter().write(processedJs);
            }
        }

        @Override
        public void destroy() {
            // 销毁时清理资源，如果有必要
        }
    }