springmvc通过request.getInputStream读取内容偶尔会卡很久

Question

以下类，是在springMvc中，通过request.getInputStream获取请求的内容，但是在bufferedReader.read读取inputStream中的内容的时候，有时候会在这里block住，有时候会在这里耗时10s-60s左右，不知道为什么？代码如下：

public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {
    @Autowired
    private Logger logger = LoggerFactory.getLogger(this.getClass());

    private final String body;

    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;
        try {
            InputStream inputStream = request.getInputStream();
            if (inputStream != null) {
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                char[] charBuffer = new char[128];
                int bytesRead = -1;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } else {
                stringBuilder.append("");
            }
        } catch (IOException ex) {
            throw ex;
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    logger.error("close bufferedReader exception, detail:", ex);
                }
            }
        }
        body = stringBuilder.toString();
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
        ServletInputStream servletInputStream = new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }

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

            @Override
            public void setReadListener(ReadListener readListener) {

            }

            public int read() throws IOException {
                return byteArrayInputStream.read();
            }
        };
        return servletInputStream;
    }

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

    public String getBody() {
        return this.body;
    }
}

Answer 1

看你代码只是读取了inputstream,如果只是为了读取json，springmvc中读取json的时候，提供了RequestBodyAdvice接口，你能自己操作解析完的json数据；没必要自己去包装request