如何解决HttpServletRequest.getInputStream()多次读取问题

 private String getBody(HttpServletRequest request) throws IOException {
    InputStream in = request.getInputStream();
    BufferedReader br = new BufferedReader(new InputStreamReader(in, Charset.forName("UTF-8")));
    StringBuffer sb = new StringBuffer("");
    String temp;
    while ((temp = br.readLine()) != null) {
        sb.append(temp);
    }
    if (in != null) {
        in.close();
    }
    if (br != null) {
        br.close();
    }
    return sb.toString();
}

String body = getBody(request);
request.setAttribute("body", body);

request.getAttribute("body");

public class RequestWrapper extends HttpServletRequestWrapper {
    private final byte[] body;
    public RequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        body = getBodyStringFromReq(request).getBytes(Charset.forName("UTF-8"));
    }
    public String getBodyString() {
        try {
            return new String(body, "UTF-8");
        } catch (UnsupportedEncodingException ex) {
            return new String(body);
        }
    }
    private String getBodyStringFromReq(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();
    }
}

public class TestFilter implements Filter {
    @Override
    public void destroy() {
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        RequestWrapper requestWrapper = new RequestWrapper((HttpServletRequest)request);
        String body = requestWrapper.getBodyString();
        chain.doFilter(requestWrapper, response);  //传入Wrapper对象
    }
    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }
}