KKFileView（九）

2021SC@SDUSC

springboot设置过滤器

一、过滤器

   过滤器是处于客户端与服务器资源文件之间的一道过滤网，在访问资源文件之前，通过一系列的过滤器对请求进行修改、判断等，把不符合规则的请求在中途拦截或修改。也可以对响应进行过滤，拦截或修改响应。

二、springboot使用多个filter过滤器

1、编写实现filter接口的类，重写其中dofilter（）方法

2、FilterConfiguration注册过滤器类，添加Bean注解

三、本项目有关过滤器

baseurlfilter        :        对请求的url规范化

public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        String baseUrl;
        StringBuilder pathBuilder = new StringBuilder();
        pathBuilder.append(request.getScheme()).append("://").append(request.getServerName()).append(":")
                .append(request.getServerPort()).append(((HttpServletRequest) request).getContextPath()).append("/");
        String baseUrlTmp = ConfigConstants.getBaseUrl();
        if (baseUrlTmp != null && !ConfigConstants.DEFAULT_BASE_URL.equals(baseUrlTmp.toLowerCase())) {
            if (!baseUrlTmp.endsWith("/")) {
                baseUrlTmp = baseUrlTmp.concat("/");
            }
            baseUrl = baseUrlTmp;
        } else {
            baseUrl = pathBuilder.toString();
        }
        BASE_URL = baseUrl;
        request.setAttribute("baseUrl", baseUrl);
        filterChain.doFilter(request, response);
    }

 ChinesePathFilter：将字符改为utf-8规范

  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        chain.doFilter(request, response);
    }

TrustHostFilter：对不安全请求拦截

 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        String url = getSourceUrl(request);
        String host = getHost(url);
        if (host != null &&!ConfigConstants.getTrustHostSet().isEmpty() && !ConfigConstants.getTrustHostSet().contains(host)) {
            String html = this.notTrustHost.replace("${current_host}", host);
            response.getWriter().write(html);
            response.getWriter().close();
        }
        chain.doFilter(request, response);
    }

WaterMarkConfigFilter：水印设置

  public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        String watermarkTxt = request.getParameter("watermarkTxt");
        request.setAttribute("watermarkTxt", watermarkTxt != null ? watermarkTxt : WatermarkConfigConstants.getWatermarkTxt());
        request.setAttribute("watermarkXSpace", WatermarkConfigConstants.getWatermarkXSpace());
        request.setAttribute("watermarkYSpace", WatermarkConfigConstants.getWatermarkYSpace());
        request.setAttribute("watermarkFont", WatermarkConfigConstants.getWatermarkFont());
        request.setAttribute("watermarkFontsize", WatermarkConfigConstants.getWatermarkFontsize());
        request.setAttribute("watermarkColor", WatermarkConfigConstants.getWatermarkColor());
        request.setAttribute("watermarkAlpha", WatermarkConfigConstants.getWatermarkAlpha());
        request.setAttribute("watermarkWidth", WatermarkConfigConstants.getWatermarkWidth());
        request.setAttribute("watermarkHeight", WatermarkConfigConstants.getWatermarkHeight());
        request.setAttribute("watermarkAngle", WatermarkConfigConstants.getWatermarkAngle());
        filterChain.doFilter(request, response);
    }