怎么让request inputstream 可以多次读取

1、包装ServletRequest对象

public class IRequestWrapper extends HttpServletRequestWrapper {
    private byte[] body;

    public IRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        body = readBytes(request.getInputStream());
    }

    public static byte[] readBytes(InputStream is) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while ((len = is.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.flush();
        return bos.toByteArray();
    }


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


    @Override
    public ServletInputStream getInputStream() {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body);
        return new ServletInputStream() {
            @Override
            public int read() {
                return byteArrayInputStream.read();
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
            }
        };

    }
}

 

2、在过滤器中应用包装

public class HttpServletRequestWrapperFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        if (request instanceof HttpServletRequest) {
            request = new IRequestWrapper((HttpServletRequest) request);
        }
        chain.doFilter(request, response);
    }


    @Override
    public void destroy() {

    }
}