图片防盗链

 

 <filter>
  <filter-name>imageRedirectFilter</filter-name>
  <filter-class>upload.ImageRedirectFilter</filter-class>
  </filter>
  <filter-mapping>
<filter-name>imageRedirectFilter</filter-name>
<url-pattern>/upload/*</url-pattern>
</filter-mapping>

 

 

package upload;

import java.io.IOException; import java.util.Properties;

import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.Filter; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.FilterChain;

public class ImageRedirectFilter implements Filter {

public void init(FilterConfig config) throws ServletException { }

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

HttpServletRequest request = (HttpServletRequest) req; HttpServletResponse response = (HttpServletResponse) res;

// 禁止缓存 response.setHeader("Cache-Control", "no-store"); response.setHeader("Pragrma", "no-cache"); response.setDateHeader("Expires", 0);

// 链接来源地址 String referer = request.getHeader("referer"); System.out.println("refer is"+referer);

Properties properties = new Properties(); properties.load(ImageRedirectFilter.class.getClassLoader()   .getResourceAsStream("config.properties")); String serverUrls = properties.getProperty("serverUrls"); String [] urls = serverUrls.split(",");

boolean bool = true; for(int i=0;i<urls.length;i++){  String url =urls[i];  if (referer.contains(url)){   bool = false;   break;  } }

 

if (referer == null || bool) {

/** * 如果 链接地址来自其他网站，则返回错误图片 */ request.getRequestDispatcher("/error.jpg").forward(request, response);

} else {

/** * 图片正常显示 */ //chain.doFilter(request, response);  request.getRequestDispatcher("/012.jpg").forward(request, response); }

}

public void destroy() { } }