在 Spring Boot Rest Controller 中处理压缩的 json 请求

Question

I've been trying to process the RequestBody which is JSON data sent as GZIP. In my RestController I have the following method:

@RequestMapping(value = "/api/data", method = RequestMethod.POST)
public ResponseEntity<String> updateData(@RequestBody String data) {
    System.out.println(data);

    return new ResponseEntity(HttpStatus.CREATED);
}

The 'data' which is sent to the controller is JSON that is GZIP-ed and when I print it, it is all encoded. How can I decode/unzip this data?

Answer 1

In the end from different sources I scraped the answer. Here's an example:

@Component
public class GzipBodyDecompressFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
            throws IOException, ServletException {
            
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        request = new GzippedInputStreamWrapper((HttpServletRequest) servletRequest);

        chain.doFilter(request, response);
    }

    final class GzippedInputStreamWrapper extends HttpServletRequestWrapper {

        public static final String DEFAULT_ENCODING = "ISO-8859-1";

        private byte[] bytes;

        public GzippedInputStreamWrapper(final HttpServletRequest request) throws IOException {
            super(request);
            try {
                final InputStream in = new GZIPInputStream(request.getInputStream());
                bytes = IOUtils.toByteArray(in);
            } catch (EOFException e) {
                bytes = new byte[0];
            }
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {
            final ByteArrayInputStream sourceStream = new ByteArrayInputStream(bytes);
            return new ServletInputStream() {
                public int read() throws IOException {
                    return sourceStream.read();
                }

                @Override
                public void setReadListener(ReadListener listener) {
                    // TODO Auto-generated method stub

                }

                @Override
                public boolean isFinished() {
                    // TODO Auto-generated method stub
                    return false;
                }

                @Override
                public boolean isReady() {
                    // TODO Auto-generated method stub
                    return false;
                }

                public void close() throws IOException {
                    super.close();
                    sourceStream.close();
                }
            };
        }

        @Override
        public Map getParameterMap() {
            return super.getParameterMap();
        }
    }
}

doFilter method will be executed before it reaches controller, in which I can do anything to the body of the request (since I have access to ServletRequest), eg creating an implementation for HttpServletRequestWrapper where I unzip the content.