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

【问题标题】：Process compressed json request in Spring Boot Rest Controller在 Spring Boot Rest Controller 中处理压缩的 json 请求
【发布时间】：2020-03-24 18:01:33
【问题描述】：

我一直在尝试处理作为 GZIP 发送的 JSON 数据的 RequestBody。在我的 RestController 我有以下方法：

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

    return new ResponseEntity(HttpStatus.CREATED);
}

发送到控制器的“数据”是经过 GZIP 压缩的 JSON，当我打印它时，它都是经过编码的。如何解码/解压缩这些数据？

【问题讨论】：

标签： json spring spring-boot gzip

【解决方案1】：

最后我从不同的来源抓取答案。这是一个例子：

@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 方法将在到达控制器之前执行，在控制器中我可以对请求的主体执行任何操作（因为我可以访问 ServletRequest），例如为我解压缩内容的 HttpServletRequestWrapper 创建一个实现。

【讨论】：