servlet读取请求参数后流失效的问题

@WebFilter(filterName="accessFilter", urlPatterns={
             "*.do",
     //        "*.jsp",
     //        "/*",
     //        "/layout/*",
     //        "/apply/*",
     //        "/audit/*",
     //        "/authority/*",
     //        "/commonWare/*",
     //        "/contract/*",
     //        "/marketing/*",
     //        "/product/*",
     //        "/project/*",
     //        "/system/*",
     //        "/user/*"
             })
     public class MyFilter implements Filter {
         //     日志对象
         private static Logger logger = Logger.getLogger(MyFilter.class);
     
         public void init(FilterConfig filterConfig) throws ServletException {
         }
         
         public void destroy() {
         }
     
         public void doFilter(ServletRequest req, ServletResponse res,FilterChain chain) throws IOException, ServletException {
             HttpServletRequest request = (HttpServletRequest) req;
             System.out.println("=====+" + req.hashCode());
             HttpServletResponse response = (HttpServletResponse) res;        
             if ("POST".equalsIgnoreCase(request.getMethod())) {
                 
                 ServletRequest requestWrapper = new BodyReaderHttpServletRequestWrapper(request);
                 System.out.println("===filter==+" + requestWrapper.hashCode());
     
                 String body = HttpUtil.getBodyString(requestWrapper);
                 System.out.println("AccessFilter="+body);
                 chain.doFilter(requestWrapper, response);
                 return ;
             }
             
             chain.doFilter(req, res);
         }
     }

public class MyHttpServletRequestWrapper extends HttpServletRequestWrapper {

        private final byte[] body;

        public MyHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
            super(request);
            body = HttpUtil.getBodyString(request).getBytes(Charset.forName("UTF-8"));
        }

        @Override
        public BufferedReader getReader() throws IOException {
            return new BufferedReader(new InputStreamReader(getInputStream()));
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {

            final ByteArrayInputStream bais = new ByteArrayInputStream(body);

            return new ServletInputStream() {

                @Override
                public int read() throws IOException {
                    return bais.read();
                }
            };
        }
    }

public static String getBodyString(ServletRequest request) {
        StringBuilder sb = new StringBuilder();
        InputStream inputStream = null;
        BufferedReader reader = null;
        try {
            inputStream = request.getInputStream();
            reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")));
            String line = "";
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return sb.toString();
    }